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Sample records for dielectric-loaded mode-selective circuit

  1. Stability study of a gyrotron-traveling-wave amplifier based on a lossy dielectric-loaded mode-selective circuit

    SciTech Connect

    Du Chaohai; Liu Pukun

    2009-07-15

    The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute instabilities characterizes the roles the forward-backward-wave components played. The study indicates that the lowest threshold current of the absolute instabilities is higher than the operating current, which brings the system high stability. The reliability of the analysis is proved by the consistency between the analysis and the NRL experimental results.

  2. G-band harmonic multiplying gyrotron traveling-wave amplifier with a mode-selective circuit

    SciTech Connect

    Yeh, Y. S.; Chen, Chang-Hong; Wang, Z. W.; Kao, B. H.; Chen, Chien-Hsiang; Lin, T. Y.; Guo, Y. W.

    2014-12-15

    Harmonic multiplying gyrotron traveling-wave amplifiers (gyro-TWAs) permit for magnetic field reduction and frequency multiplication. A high-order-mode harmonic multiplying gyro-TWA with large circuit dimensions and low ohmic loss can achieve a high average power. By amplifying a fundamental harmonic TE{sub 01} drive wave, the second harmonic component of the beam current initiates a TE{sub 02} wave to be amplified. Wall losses can suppress some competing modes because they act as an effective sink of the energy of the modes. However, such wall losses do not suppress all competing modes as the fields are contracted in the copper section in the gyro-TWA. An improved mode-selective circuit, using circular waveguides with the specified radii, can provide the rejection points within the frequency range to suppress the competing modes. The simulated results reveal that the mode-selective circuit can provide an attenuation of more than 10 dB to suppress the competing modes (TE{sub 21}, TE{sub 51}, TE{sub 22}, and TE{sub 03}). A G-band second harmonic multiplying gyro-TWA with the mode-selective circuit is predicted to yield a peak output power of 50 kW at 198.8 GHz, corresponding to a saturated gain of 55 dB at an interaction efficiency of 10%. The full width at half maximum bandwidth is 5 GHz.

  3. G-band harmonic multiplying gyrotron traveling-wave amplifier with a mode-selective circuit

    NASA Astrophysics Data System (ADS)

    Yeh, Y. S.; Chen, Chang-Hong; Wang, Z. W.; Kao, B. H.; Chen, Chien-Hsiang; Lin, T. Y.; Guo, Y. W.

    2014-12-01

    Harmonic multiplying gyrotron traveling-wave amplifiers (gyro-TWAs) permit for magnetic field reduction and frequency multiplication. A high-order-mode harmonic multiplying gyro-TWA with large circuit dimensions and low ohmic loss can achieve a high average power. By amplifying a fundamental harmonic TE01 drive wave, the second harmonic component of the beam current initiates a TE02 wave to be amplified. Wall losses can suppress some competing modes because they act as an effective sink of the energy of the modes. However, such wall losses do not suppress all competing modes as the fields are contracted in the copper section in the gyro-TWA. An improved mode-selective circuit, using circular waveguides with the specified radii, can provide the rejection points within the frequency range to suppress the competing modes. The simulated results reveal that the mode-selective circuit can provide an attenuation of more than 10 dB to suppress the competing modes ( TE 21 , TE 51 , TE 22 , and TE 03 ). A G-band second harmonic multiplying gyro-TWA with the mode-selective circuit is predicted to yield a peak output power of 50 kW at 198.8 GHz, corresponding to a saturated gain of 55 dB at an interaction efficiency of 10%. The full width at half maximum bandwidth is 5 GHz.

  4. Dielectrically loaded horns

    NASA Astrophysics Data System (ADS)

    Tun, S. M.; Bustamante, R.; Williams, N.

    Dielectrically loaded horns have been proposed as alternatives to conical corrugated horns in high-performance primary feeds in virtue both of their lower cost and theoretical indications of superior operational bandwidth performance, while retaining circularly symmetric radiation, low sidelobes, and low cross-polarization. A prototype dielectric core-loaded horn, and a dual-band transmit/receive horn antenna incorporating a dielectric rod inside a small corrugated horn, have been developed and tested; the dielectric used for the rod is Rexolite. The high performance obtainable by this inexpensive technology has been experimentally demonstrated.

  5. Three-dimensional numerical modeling of photonic integration with dielectric-loaded SPP waveguides

    NASA Astrophysics Data System (ADS)

    Krasavin, A. V.; Zayats, A. V.

    2008-07-01

    Using full three-dimensional numerical modeling, we demonstrate highly efficient passive and active photonic circuit elements based on dielectric-loaded surface plasmon polariton waveguides (DLSPPWs). Highly confined surface plasmon polariton (SPP) mode having subwavelength cross section allows high level of integration of DLSPPW circuitry. We demonstrate very efficient guiding and routing of SPP signals with the passive waveguide elements such as bends, splitters, and Bragg reflectors, having a functional size of just a few microns at telecommunication wavelengths. Introducing a gain in the dielectric, we have found the requirement for lossless waveguiding and estimated the performance of DLSPPW lossless and active elements. DLSPPW based components have prospective implementation in photonic integrated chips, hybrid optical-electronic circuits, and lab-on-a-chip applications.

  6. Development of a dual layered dielectric-loaded accelerating structure.

    SciTech Connect

    Gai, W.; Liu, W.; Jing, C.; Kanareykin, A.; Antipov, S.; Nenasheva, E.; Schoessow, P.; High Energy Physics; Euclid Techlabs, LLC; Illinois Inst. of Tech.; KEK

    2008-09-01

    Due to the high magnetic field-induced surface currents on its conducting sleeve, a conventional single layer Dielectric-Loaded Accelerating (DLA) structure exhibits a relatively high RF loss. One possible way to solve this problem is to use multilayered DLA structures. In these devices, the RF power attenuation is reduced by making use of the Bragg Fiber concept: the EM fields are well confined by multiple reflections from multiple dielectric layers. This paper presents the design of an X-band dual layer DLA structure as well as the results of bench tests of the device. We will also present results on the design, numerical modeling, and fabrication of structures for coupling RF into multilayer DLAs such as a novel TM{sub 03} mode launcher and a TM{sub 01}-TM{sub 03} mode converter using dielectric-loaded corrugated waveguide.

  7. Dihedron dielectric loaded surface plasmon athermal polarization converter.

    PubMed

    Hassan, K; Leroy, F; Colas-des-Francs, G; Weeber, J-C

    2014-02-01

    We investigate numerically a novel plasmonic polarization converter relying on the excitation of a so-called dihedron dielectric loaded plasmon polariton. The dihedron dielectric loaded waveguide consists of a dielectric ridge implemented at the inner corner of a metal-coated dielectric step. For a dielectric ridge with a square cross section, the plasmon polariton modes supported by each side of the metallized step hybridize to create supermodes with crossed polarizations. We show that the two supermodes can be operated in a dual-mode interferometer configuration to perform an efficient (24 dB) TE-TM/TM-TE polarization conversion over typical distances below 30 μm at telecommunications wavelengths. In addition, on the basis of the thermo-optical properties of our device, we find that the dihedron plasmonic polarization converter is temperature insensitive. PMID:24487902

  8. Electrically tuneable directional coupling and switching based on multimode interference effect in dielectric loaded graphene plasmon waveguides

    NASA Astrophysics Data System (ADS)

    Qi, Zhe; Zhu, Zhihong; Xu, Wei; Zhang, Jianfa; Guo, Chucai; Liu, Ken; Yuan, Xiaodong; Qin, Shiqiao

    2016-06-01

    We have numerically demonstrated that electrically tuneable directional coupling and switching can be realized based on the multimode interference effect in dielectric-loaded graphene plasmon waveguides (DLGPWs) of our own design. The total field profile resulting from a superposition of all guided modes in the multimode dielectric-loaded graphene plasmon waveguide is electrically controllable because the propagation properties of the first three guided modes supported by the DLGPW can be effectively manipulated by electrostatic doping of graphene. The functional size of the device is only several micrometres, which is much smaller than the working wavelength. Such electrically controlled multifunctional devices may find potential applications in high-density integrated active plasmonic circuits.

  9. Development of X-Band Dielectric-Loaded Accelerating Structures

    SciTech Connect

    Gold, S. H.; Jing, C.; Kanareykin, A.; Gai, W.; Konecny, R.; Power, J. G.; Kinkead, A. K.

    2010-11-04

    This paper presents a progress report on the development and testing of X-band dielectric-loaded accelerating structures. Recent tests on several quartz DLA structures with different inner diameters are reported. Designs for gap-free DLA structures are presented. Also, planned new experiments are discussed, including higher gradient traveling-wave and standing-wave structures and special grooved structures for multipactor suppression.

  10. Nonlinear analysis of the dielectric loaded rectangular Cerenkov maser

    NASA Astrophysics Data System (ADS)

    Zhao, Ding; Ding, Yaogen

    2012-02-01

    To deeply investigate the nonlinear interaction between the sheet beam and the slow wave mode in the dielectric loaded rectangular Cerenkov maser, a third order differential equation of the field profile function is rigorously derived. By combining with the relativistic equation of motion and using the traveling-wave boundary condition, the nonlinear phenomena, which involve with the growth rate, the electron phase bunching, the saturated power and length, etc., can be predicted through numerical calculations. An illustrative example has been given to demonstrate the validation of this method. The results show that a beam with axial momentum spread will lower the saturated power, increase the saturated length, and decrease the working bandwidth.

  11. Tunable graphene near-IR dielectric loaded waveguides

    NASA Astrophysics Data System (ADS)

    Liu, Chunlin; He, Xiaoyong; Zhao, Zhenyu; Lin, Fangting; Liu, Feng; Shi, Wangzhou

    2016-07-01

    By integrating the graphene layer with the dielectric loaded surface plasmon waveguides, the tunable propagation properties have been investigated in the near-IR region, including the influences of operation frequency, the Fermi level of the graphene layer, and dielectric layer thickness. To improve the modulation properties, multiple unit cell (graphene-Al2O3) structure has been adopted. The results manifest that as the period number of the unit cell increases, the modulation depths of the propagation properties increase obviously. For instance, the modulation depth of propagation length can reach about 80% if the Fermi level changes in the range of 0.1–0.5 eV. As frequency increases, the effective index of the hybrid mode increases, while the propagation length shows a peak. The results are very helpful in understanding the tunable mechanisms of graphene plasmonic devices and designing novel waveguide structures, e.g. resonators and modulators.

  12. Multipactor Modeling in Cylindrical Dielectric-Loaded Accelerators

    SciTech Connect

    Power, John G.; Gold, Steven H.

    2006-11-27

    The observation of strong multipactor loading of a cylindrical dielectric-loaded accelerator (DLA) structure with an alumina liner was previously reported. Conventional multipactor loading of dielectric rf windows is due to a tangential rf electric field and generally saturates at a few percent power loss. However, this resonant single-surface multipactor is driven by a combination of normal and tangential rf electric fields, is a strong function of the incident power, and is capable of absorbing a large fraction (over 1/2) of the incident rf power. Since the initial report, several additional structures have been tested, fabricated from a variety of materials, some with low secondary-emission surface coatings, and having different physical dimensions. In this paper, we summarize the results of these tests and analyze the results in terms of a physical model of the multipactor phenomenon.

  13. Multipactor discharge in a dielectric-loaded accelerating structure

    NASA Astrophysics Data System (ADS)

    Wu, L.; Ang, L. K.

    2007-01-01

    This paper presents a Monte-Carlo model to explain the multipactor discharge and its high-power absorption in a dielectric-loaded accelerating (DLA) structure reported recently [J. G. Power et al., Phys. Rev. Lett. 92, 164801 (2004)]. Susceptibility diagrams are constructed. Dynamic calculations for beam loading and its power absorption by the multipactor discharge are performed. It is found that the fraction of power absorbed by multipactor discharge at saturation is much larger than the case of a simple rf window, and it is sensitive to the incident power, which confirms the prior experimental results. This enhanced power absorption is due to the fact that the length of a DLA structure is much larger than the radius of the structure. A resonant condition of a maximum growth region has also been determined numerically and analytically. The difference between the resonant condition and saturation (due to beam loading) is clarified.

  14. Rectangular Dielectric-loaded Structures for Achieving High Acceleration Gradients

    SciTech Connect

    Wang Changbiao; Yakovlev, V. P.; Marshall, T. C.; LaPointe, M. A.; Hirshfield, J. L.

    2006-11-27

    Rectangular dielectric-loaded structures are described that may sustain higher acceleration gradients than conventional all-metal structures with similar apertures. One structure is a test cavity designed to ascertain the breakdown limits of dielectrics, while a second structure could be the basis for a two-beam accelerator. CVD diamond is an attractive dielectric for a high-gradient structure, since the published DC breakdown limit for CVD diamond is {approx} 2 GV/m, although the limit has never been determined for RF fields. Here we present a design of a diamond-lined test cavity to measure the breakdown limit. The designed cavity operates at 34 GHz, where with 10-MW input power it is expected to produce an {approx}800 MV/m field on the diamond surface - provided breakdown is avoided. The two channel rectangular dielectric-loaded waveguide could be a two-beam accelerator structure, in which a drive beam is in one channel and an accelerated beam is in the other. The RF power produced by drive bunches in the drive channel is continuously coupled to the acceleration channel. The ratio of fields in the channels (transformer ratio) for the operating mode can be designed by adjusting the dimensions of the structure. An example of the two-channel structure is described, in which a train of five 3-nC drive bunches excites wake fields in the accelerator channel of up to 1.3 GV/m with a transformer ratio of 10 for the design mode.

  15. Numerical studies of multipactor in dielectric-loaded accelerator structures

    NASA Astrophysics Data System (ADS)

    Sinitsyn, Oleksandr; Nusinovich, Gregory; Antonsen, Thomas

    2009-11-01

    Multipactor (MP) is known as the avalanche growth of the number of secondary electrons emitted from a solid surface exposed to an rf electric field under vacuum conditions. MP may occur in various microwave and rf systems such as microwave tubes, rf windows and launchers, accelerating structures, and rf satellite payloads. In this work we present results of MP analysis in dielectric-loaded accelerator (DLA) structures. The starting point of our work was experimental and theoretical studies of DLA structures jointly done by Argonne National Laboratory and Naval Research Laboratory (J. G. Power et al., Phys. Rev. Lett. 92, 164801 (2004); J. G. Power et al., AIP Conf. Proc. 877, 362 (2006)). In the theoretical model developed during those studies the space-charge field due to the total number of particles is taken into account as a parameter. We perform our studies using a self-consistent approach with the help of time-dependent two-dimensional code developed at the University of Maryland (O. V. Sinitsyn et al., Phys. Plasmas 16, 073102 (2009)). Results include analysis of MP evolution at an early stage, detailed studies of individual electron trajectories, analysis of MP onset time under various conditions and comparison of some results with the experimental data.

  16. Electro-optic switching based on a waveguide-ring resonator made of dielectric-loaded graphene plasmon waveguides

    NASA Astrophysics Data System (ADS)

    Qi, Zhe; Zhu, Zhi Hong; Xu, Wei; Zhang, Jian Fa; Cai Guo, Chu; Liu, Ken; Yuan, Xiao Dong; Qiao Qin, Shi

    2016-09-01

    We numerically demonstrate that electro-optic switching in the mid-infrared range can be realized using a waveguide-ring resonator made of dielectric-loaded graphene plasmon waveguides (DLGPWs). The numerical results are in good agreement with the results of physical analysis. The switching mechanism is based on dynamic modification of the resonant wavelengths of the ring resonator, achieved by varying the Fermi energy of a graphene sheet. The results reveal that a switching ratio of ∼24 dB can be achieved with only a 0.01 eV change in the Fermi energy. Such electrically controlled switching operation may find use in actively tunable integrated photonic circuits.

  17. Two-stage dielectric-loading for broadbanding a gyro-TWT

    SciTech Connect

    Rao, S.J.; Jain, P.K.; Basu, B.N.

    1996-06-01

    A scheme of dielectric-loading for a gyro-traveling-wave tube (gyro-TWT) is proposed for a wider bandwidth at a higher gain. The method uses two-section dielectric-loaded cylindrical waveguide as the interaction structure, with the first section overloaded to exhibit a valley between the two peaks in the gain-frequency response, while the other suitably loaded to exhibit a single peak centered at the valley so as to yield an overall wideband response. A bandwidth {approximately}8.8% at a relatively high small-signal gain {approximately}30 dB is predicted.

  18. Experimental demonstration of wakefield acceleration in a tunable dielectric loaded accelerating structure.

    PubMed

    Jing, C; Kanareykin, A; Power, J G; Conde, M; Liu, W; Antipov, S; Schoessow, P; Gai, W

    2011-04-22

    We report on a collinear wakefield experiment using the first tunable dielectric loaded accelerating structure. By introducing an extra layer of nonlinear ferroelectric, which has a dielectric constant sensitive to temperature and dc bias, the frequency of a dielectric loaded accelerating structure can be tuned. During the experiment, the energy of a witness bunch at a fixed delay with respect to the drive beam was measured while the temperature of the structure was scanned over a 50 °C range. The energy change corresponded to a change of more than half of the nominal structure wavelength. PMID:21599371

  19. Experimental demonstration of Wakefield acceleration in a tunable dielectric loaded accelerating structure.

    SciTech Connect

    Liu, W.; Power, J. G.; Conde, M.; Antipov, S.; Schoessow, P.; Gai, W.; Jing, C.; Kanareykin, A.; Schoessow, P.

    2011-04-21

    We report on a collinear wakefield experiment using the first tunable dielectric loaded accelerating structure. By introducing an extra layer of nonlinear ferroelectric, which has a dielectric constant sensitive to temperature and dc bias, the frequency of a dielectric loaded accelerating structure can be tuned. During the experiment, the energy of a witness bunch at a fixed delay with respect to the drive beam was measured while the temperature of the structure was scanned over a 50 C range. The energy change corresponded to a change of more than half of the nominal structure wavelength.

  20. Experimental Demonstration of Wakefield Acceleration in a Tunable Dielectric Loaded Accelerating Structure

    SciTech Connect

    Jing, C.; Antipov, S.; Kanareykin, A.; Schoessow, P.; Power, J. G.; Conde, M.; Liu, W.; Gai, W.

    2011-04-22

    We report on a collinear wakefield experiment using the first tunable dielectric loaded accelerating structure. By introducing an extra layer of nonlinear ferroelectric, which has a dielectric constant sensitive to temperature and dc bias, the frequency of a dielectric loaded accelerating structure can be tuned. During the experiment, the energy of a witness bunch at a fixed delay with respect to the drive beam was measured while the temperature of the structure was scanned over a 50 deg. C range. The energy change corresponded to a change of more than half of the nominal structure wavelength.

  1. First operation of a dielectric-loaded double-stripline free-electron maser experiment

    SciTech Connect

    Einat, M.; Jerby, E.; Shahadi, A.

    1995-12-31

    A tabletop free-electron maser (FEM) experiment based on a dielectric-loaded double-stripline waveguide is presented. It employs a low-energy (8 keV, 0.5 A) electron beam and a folded-foil wiggler ({lambda}w = 2 cm). Metal striplines protects the dielectric slabs from the electron beam and support quasi-TEM modes in the waveguide. Radiation output is observed at f = 3.5 GHz, in agreement with the dielectric-loaded FEM tuning relation.

  2. Wakefield Generation in Compact Rectangular Dielectric Loaded Structures Using Flat Beams

    NASA Astrophysics Data System (ADS)

    Stoltz, Peter; Piot, Philippe; Cowan, Ben; Lemery, Francois; Mihalcea, Daniel; Prokop, Chris; Smith, Jonathan; Smithe, David

    2011-10-01

    Wakefields with amplitude in the 10s MV/m range can be routinely generated by passing electron beams through dielectric-loaded structures. The main obstacle in obtaining high field amplitude (in the GV/m range) is the ability to focus the high-peak-current electron beam in the transverse plane to micron level, and to maintain the focusing all the way along the dielectric structure. In this paper we explore the use of a flat, high-peak current, electron beams to be produced at the Fermilab NML facility to drive dielectric loaded structures. Based on beam dynamics simulation we anticipate that we can obtain flat beams with very small vertical size (under 100 microns) and peak current is in excess of 1 kA. We present simulations of the wakefield generation based on theoretical models and PIC simulations with VORPAL. Work supported by DTRA Grant Number HDTRA1-10-1-0051.

  3. 7.8GHz High power generation and extraction with a dielectric-loaded waveguide.

    SciTech Connect

    Conde, M. E.; Gai, W.; Konecny, R.; Power, J. G.; Gao, F.; Wong, T.; Yusof, Z.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs

    2009-01-01

    In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.

  4. 7.8 GHz High Power Generation And Extraction With A Dielectric-loaded Waveguide

    SciTech Connect

    Gao, F.; Conde, M. E.; Gai, W.; Konecny, R.; Liu, W.; Power, J. G.; Yusof, Z.; Jing, C.; Wong, T.

    2009-01-22

    In this paper, we present updated results on power extraction testing of a 7.8 GHz dielectric loaded waveguide power extractor using both high charge single bunches and bunch trains. We have generated a 1.7 ns radio frequency (rf) pulse with 30 MW of power with a single 66 nC electron bunch. Then we have generated a pulse train of electron beam for rf generation of 10 ns and 22 ns rf pulses.

  5. Development of a 20-MeV Dielectric-Loaded Accelerator Test Facility

    SciTech Connect

    Gold, S.H.; Kinkead, A.K.; Gai, W.; Power, J.G.; Konecny, R.; Jing, C.G.; Tantawi, S.G.; Nantista, C.D.; Hu, Y.; Chen, H.; Tang, C.; Lin, Y.; Bruce, R.W.; Bruce, R.L.; Fliflet, A.W.; Lewis, D.; /Naval Research Lab, Wash., D.C. /LET Corp., Washington /Argonne /SLAC /Tsinghua U., Beijing

    2005-06-22

    This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron inector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to {approx} 8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRl, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator.

  6. Development of a Compact Dielectric-Loaded Test Accelerator at 11.4 GHz

    SciTech Connect

    Gold, S. H.; Fliflet, A. W.; Kinkead, A. K.; Gai, W.; Power, J. G.; Konecny, R.; Jing, C.

    2009-01-22

    This paper presents a progress report on the development of a dielectric-loaded test accelerator in the Magnicon Facility at the Naval Research Laboratory (NRL). The accelerator will be powered by an 11.4-GHz magnicon amplifier that provides up to 25 MW of output power in a {approx}250-ns pulse at up to 10 Hz. The accelerator includes a 5-MeV electron injector originally developed at the Tsinghua University in Beijing, China, and can incorporate dielectric-loaded accelerating (DLA) structures of up to 0.5 m in length. The DLA structures are being developed by Argonne National Laboratory and Euclid Techlabs, and shorter test structures fabricated from a variety of dielectric materials have undergone rf testing at NRL at accelerating gradients up to 15 MV/m. The first stage of the accelerator, including the 5-MeV injector, has recently begun operation, and initial operation of the complete dielectric-loaded test accelerator, including injector, DLA test structure, and spectrometer, should take place within the next year.

  7. Mode selective directional coupler for NLC

    SciTech Connect

    Tantawi, S.G.

    1994-10-01

    The design method for a high power, X-band, 50 dB, circular to rectangular directional coupler is presented. The circular guide is over moded and is intended to operate in TE{sub 01} mode. The rectangular guide operates at the fundamental TE{sub 10} mode. A small percentage of higher order modes in the circular guide can cause considerable errors in the measurements because the magnitude of the axial magnetic field of these modes is higher than that of the operating mode, especially near their cutoff. We used a Hamming window patten for the coupling slots to achieve mode selectivity. Comparison of theory and experiment will be presented.

  8. Mode Selective Excitation Using Coherent Control Spectroscopy

    SciTech Connect

    Singh, Ajay K.; Konradi, Jakow; Materny, Arnulf; Sarkar, Sisir K.

    2008-11-14

    Femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) gives access to ultrafast molecular dynamics. However, femtosecond laser pulses are spectrally broad and therefore coherently excite several molecular modes. While the temporal resolution is high, usually no mode-selective excitation is possible. This paper demonstrates the feasibility of selectively exciting specific molecular vibrations in solution phase with shaped fs laser excitation using a feedback-controlled optimization technique guided by an evolutionary algorithm. This approach is also used to obtain molecule-specific CARS spectra from a mixture of different substances. The optimized phase structures of the fs pulses are characterized to get insight into the control process. Possible applications of the spectrum control are discussed.

  9. Enhance the terahertz Smith-Purcell superradiant radiation by using dielectric loaded grating

    SciTech Connect

    Cao, Miaomiao Li, Ke; Liu, Wenxin Wang, Yong

    2015-08-15

    A dielectric loaded grating (DLG) for terahertz Smith-Purcell (SP) device is proposed to enhance the radiation intensity. By using the theoretical analysis and particle-in-cell simulations, the dispersion characteristics and SP superradiant radiation are investigated. Compared with the general metal grating, the usage of DLG can improve the magnitude of electric field and, consequently, strengthen the interaction of the evanescent wave with electron beam, which can improve the growth rate, enhance the SP superradiant radiation, and lower the start current for the operation of SP free-electron laser.

  10. Studies of Multipactor in Dielectric-Loaded Accelerator Structures: Comparison of Simulation Results with Experimental Data

    SciTech Connect

    Sinitsyn, Oleksandr; Nusinovich, Gregory; Antonsen, Thomas Jr.

    2010-11-04

    In this paper new results of numerical studies of multipactor in dielectric-loaded accelerator structures are presented. The results are compared with experimental data obtained during recent studies of such structures performed by Argonne National Laboratory, the Naval Research Laboratory, SLAC National Accelerator Laboratory and Euclid TechLabs, LLC. Good agreement between the theory and experiment was observed for the structures with larger inner diameter, however the structures with smaller inner diameter demonstrated a discrepancy between the two. Possible reasons for such discrepancy are discussed.

  11. Development of a 20 MeV Dielectric-Loaded Test Accelerator

    SciTech Connect

    Gold, S.H.; Kinkead, A.K.; Gai, W.; Power, J.G.; Konecny, R.; Jing, C.; Long, J.; Tantawi, S.G.; Nantista, C.D.; Fliflet, A.W.; Lombardi, M.; Lewis, D.; Bruce, R.W.; /Unlisted

    2007-04-13

    This paper presents a progress report on a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded test accelerator in the magnicon facility at NRL. The accelerator will be powered by an experimental 11.424-GHz magnicon amplifier that presently produces 25 MW of output power in a {approx}250-ns pulse at up to 10 Hz. The accelerator will include a 5-MeV electron injector originally developed at the Tsinghua University in Beijing, China, and can incorporate DLA structures up to 0.5 m in length. The DLA structures are being developed by ANL, and shorter test structures fabricated from a variety of dielectric materials have undergone testing at NRL at gradients up to {approx}8 MV/m. SLAC has developed components to distribute the power from the two magnicon output arms to the injector and to the DLA accelerating structure with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRL, has investigated means to join short ceramic sections into a continuous accelerator tube by a brazing process using an intense 83-GHz beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA test structure, and spectrometer, should take place within the next year.

  12. Development of a 20 MeV Dielectric-Loaded Test Accelerator

    SciTech Connect

    Gold, Steven H.; Fliflet, Arne W.; Lombardi, Marcie; Kinkead, Allen K.; Gai, Wei; Power, John G.; Konecny, Richard; Long, Jidong; Jing, Chunguang; Tantawi, Sami G.; Nantista, Christopher D.; Bruce, Ralph W.; Lewis, David III

    2006-11-27

    This paper presents a progress report on a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded test accelerator in the magnicon facility at NRL. The accelerator will be powered by an experimental 11.424-GHz magnicon amplifier that presently produces 25 MW of output power in a {approx}250-ns pulse at up to 10 Hz. The accelerator will include a 5-MeV electron injector originally developed at the Tsinghua University in Beijing, China, and can incorporate DLA structures up to 0.5 m in length. The DLA structures are being developed by ANL, and shorter test structures fabricated from a variety of dielectric materials have undergone testing at NRL at gradients up to {approx}8 MV/m. SLAC has developed components to distribute the power from the two magnicon output arms to the injector and to the DLA accelerating structure with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRL, has investigated means to join short ceramic sections into a continuous accelerator tube by a brazing process using an intense 83-GHz beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA test structure, and spectrometer, should take place within the next year.

  13. Dispersion characteristics of three-dimensional dielectric-loaded grating for terahertz Smith-Purcell radiation

    SciTech Connect

    Cao, Miaomiao Li, Ke; University of Chinese Academy of Sciences, Beijing 100049 ; Liu, Wenxin Wang, Yong

    2014-02-15

    In this paper, a dielectric-loaded grating for Smith-Purcell device is proposed. The three-dimensional (3D) analytical theory for hot dispersion relation is obtained by using field matched method, which is solved by numerical simulations. The first and second order growth rates for the proposal model are analyzed, which is obtained by expanding hot dispersion equation at the operating point. The results show that the dispersion can be effectively weakened by introducing dielectric-loaded grating, in which the cutoff frequency is affected by the grating thickness. The dispersion curve becomes flatter and shifts towards lower frequency at the optimum grating parameters. The 3D particle-in-cell (PIC) simulation is also performed and the results are in good agreement with theoretical calculations. Comparing the first order growth rate with the second one, it reveals that the discrepancy is small when electron beam parameters are selected with small values. Otherwise, the discrepancy is large and cannot be ignored. To accurately describe the process of beam-wave interaction, the second order growth rate is necessary to apply.

  14. Update on the development of externally powered dielectric-loaded accelerating structures.

    SciTech Connect

    Jing, C.; Gai, W.; Konecny, R.; Power, J. G.; Liu, W.; Kanareykin, A.; Gold, S.; Kinkead, A. K.; High Energy Physics; EuclidTechlabs,; Naval Research Lab.; Icarus Research

    2009-01-01

    We report on recent progress in a program to develop an RF-driven Dielectric-Loaded Accelerating (DLA) structure, capable of supporting high gradient acceleration. Previous high power tests revealed that the earlier DLA structures suffered from multipactor and arcing at the dielectric joint. A few new DLA structures have been designed to alleviate this limitation including the coaxial coupler based DLA structure and the clamped DLA structure. These structures were recently fabricated and high power tested at the NRL X-band Magnicon facility. Results show the multipactor can be reduced by the TiN coating on the dielectric surface. Gradient of 15 MV/m has also been tested without dielectric breakdown in the test of the clamped DLA structure. Detailed results are reported, and future plans discussed.

  15. Integrated plasmonic semi-circular launcher for dielectric-loaded surface plasmon-polariton waveguide.

    PubMed

    Li, Xiaowei; Huang, Lingling; Tan, Qiaofeng; Bai, Benfeng; Jin, Guofan

    2011-03-28

    A semi-circular plasmonic launcher integrated with dielectric-loaded surface plasmon-polaritons waveguide (DLSPPW) is proposed and analyzed theoretically, which can focus and efficiently couple the excited surface plasmon polaritons (SPPs) into the DLSPPW via the highly matched spatial field distribution with the waveguide mode in the focal plane. By tuning the incident angle or polarization of the illuminating beam, it is shown that the launcher may be conveniently used as a switch or a multiplexer that have potential applications in plasmonic circuitry. Furthermore, from an applicational point of view, it is analyzed how the coupling performance of the launcher can be further improved by employing multiple semi-circular slits. PMID:21451682

  16. Cherenkov radiation from a relativistic annular electron beam propagating through a dielectric loaded waveguide

    NASA Astrophysics Data System (ADS)

    Uhm, H. S.

    1981-11-01

    The stability properties of the free-streaming mode (space-charge wave) in a relativistic annular electron beam with radius R sub 0 propagating through a dielectric loaded waveguide is studied in connection with the Cherenkov radiation. The stability analysis is carried out within the framework of the linearized Vlasov-Maxwell equations for an electron distribution function, where all electrons have a Lorentzian distribution in the axial canonical momentum. One of the most significant features of the analysis is that, for some ranges of physical parameters, a strong mode coupling between the vacuum dielectric waveguide and free streaming modes occurs, exhibiting possibilities of a Cherenkov radiation. It is found that the typical maximum growth rate of instability is a few percent of c/R sub 0, c being the speed of light in vacuo.

  17. Progress toward externally powered x-band dielectric-loaded accelerating structures.

    SciTech Connect

    Gai, W.; Power, J. G.; Liu, W.; Jing, C.; Gold, S. H.; Kinead, A. K.; Tantawi, S. G.; Dolgashev, V.; Kanareykin, A.; Konecny, R.; Wanming, L.

    2010-06-01

    We summarize recent progress in a program to develop externally powered dielectric-loaded accelerating (DLA) structures that can sustain high accelerating gradients. High-power RF tests of earlier structures showed strong multipactor loading. In addition, arcing at dielectric joints between the uniform DLA structure and matching sections at either end limited the achievable gradient. In this paper, we study the onset of multipactor in a DLA structure. We also study the effect of thin-film TiN coatings applied by atomic layer deposition and the effect of a reduction in the inner diameter of the structure. Test results of these structures show significant decreases in multipactor loading. We also test new structure designs that eliminate separate dielectric matching sections and, thus, the requirement for dielectric joints, including a DLA structure using a coaxial coupler and a clamped DLA structure. The clamped structure demonstrated a significantly improved gradient without breakdown.

  18. Update on the Development of Externally Powered Dielectric-Loaded Accelerating Structures

    SciTech Connect

    Jing, C.; Kanareykin, A.; Gai, W.; Konecny, R.; Power, J. G.; Liu, W.; Gold, S. H.; Kinkead, A. K.

    2009-01-22

    We report on recent progress in a program to develop an RF-driven Dielectric-Loaded Accelerating (DLA) structure, capable of supporting high gradient acceleration. Previous high power tests revealed that the earlier DLA structures suffered from multipactor and arcing at the dielectric joint. A few new DLA structures have been designed to alleviate this limitation including the coaxial coupler based DLA structure and the clamped DLA structure. These structures were recently fabricated and high power tested at the NRL X-band Magnicon facility. Results show the multipactor can be reduced by the TiN coating on the dielectric surface. Gradient of 15 MV/m has also been tested without dielectric breakdown in the test of the clamped DLA structure. Detailed results are reported, and future plans discussed.

  19. 3D Analysis of Wake Field Excitation in a Dielectric Loaded Rectangular Resonator

    SciTech Connect

    Sotnikov, Gennadij V.; Onishchenko, Ivan N.; Marshall, Thomas C.

    2006-11-27

    The results of a three-dimensional analysis of wake field excitation in a slab-symmetric dielectric-loaded resonator by rigid electron bunches are presented. The complete set of solutions, including the solenoidal and potential parts of the electromagnetic field, consists of LSM and LSE modes. Each of the LSM and LSE modes contains odd and even waves. A numerical analysis of wake field excitation by symmetric electron bunches is carried out. The three-dimensional spatial structure of the longitudinal electric field is investigated. The influence of the drift vacuum channel on the wake field amplitude and on the coherent summation of wakefields for a regular sequence of bunches is studied.

  20. Dielectric-loaded waveguide circulator for cryogenically cooled and cascaded maser waveguide structures

    NASA Technical Reports Server (NTRS)

    Clauss, R. C.; Quinn, R. B. (Inventor)

    1980-01-01

    A dielectrically loaded four port waveguide circulator is used with a reflected wave maser connected to a second port between first and third ports to form one of a plurality of cascaded maser waveguide structures. The fourth port is connected to a waveguide loaded with microwave energy absorbing material. The third (output signal) port of one maser waveguide structure is connected by a waveguide loaded with dielectric material to the first (input) port of an adjacent maser waveguide structure, and the second port is connected to a reflected wave maser by a matching transformer which passes the signal to be amplified into and out of the reflected wavemaser and blocks pumping energy in the reflected wave maser from entering the circulator. A number of cascaded maser waveguide structures are thus housed in a relatively small volume of conductive material placed within a cryogenically cooled magnet assembly.

  1. Complete multipactor suppression in an X-band dielectric-loaded accelerating structure

    NASA Astrophysics Data System (ADS)

    Jing, C.; Gold, S. H.; Fischer, Richard; Gai, W.

    2016-05-01

    Multipactor is a major issue limiting the gradient of rf-driven Dielectric-Loaded Accelerating (DLA) structures. Theoretical models have predicted that an axial magnetic field applied to DLA structures may completely block the multipactor discharge. However, previous attempts to demonstrate this magnetic field effect in an X-band traveling-wave DLA structure were inconclusive, due to the axial variation of the applied magnetic field, and showed only partial suppression of the multipactor loading [Jing et al., Appl. Phys. Lett. 103, 213503 (2013)]. The present experiment has been performed under improved conditions with a uniform axial magnetic field extending along the length of an X-band standing-wave DLA structure. Multipactor loading began to be continuously reduced starting from 3.5 kG applied magnetic field and was completely suppressed at ˜8 kG. Dependence of multipactor suppression on the rf gradient inside the DLA structure was also measured.

  2. Polarization-tuned Dynamic Color Filters Incorporating a Dielectric-loaded Aluminum Nanowire Array

    PubMed Central

    Raj Shrestha, Vivek; Lee, Sang-Shin; Kim, Eun-Soo; Choi, Duk-Yong

    2015-01-01

    Nanostructured spectral filters enabling dynamic color-tuning are saliently attractive for implementing ultra-compact color displays and imaging devices. Realization of polarization-induced dynamic color-tuning via one-dimensional periodic nanostructures is highly challenging due to the absence of plasmonic resonances for transverse-electric polarization. Here we demonstrate highly efficient dynamic subtractive color filters incorporating a dielectric-loaded aluminum nanowire array, providing a continuum of customized color according to the incident polarization. Dynamic color filtering was realized relying on selective suppression in transmission spectra via plasmonic resonance at a metal-dielectric interface and guided-mode resonance for a metal-clad dielectric waveguide, each occurring at their characteristic wavelengths for transverse-magnetic and electric polarizations, respectively. A broad palette of colors, including cyan, magenta, and yellow, has been attained with high transmission beyond 80%, by tailoring the period of the nanowire array and the incident polarization. Thanks to low cost, high durability, and mass producibility of the aluminum adopted for the proposed devices, they are anticipated to be diversely applied to color displays, holographic imaging, information encoding, and anti-counterfeiting. PMID:26211625

  3. Polarization-tuned Dynamic Color Filters Incorporating a Dielectric-loaded Aluminum Nanowire Array

    NASA Astrophysics Data System (ADS)

    Raj Shrestha, Vivek; Lee, Sang-Shin; Kim, Eun-Soo; Choi, Duk-Yong

    2015-07-01

    Nanostructured spectral filters enabling dynamic color-tuning are saliently attractive for implementing ultra-compact color displays and imaging devices. Realization of polarization-induced dynamic color-tuning via one-dimensional periodic nanostructures is highly challenging due to the absence of plasmonic resonances for transverse-electric polarization. Here we demonstrate highly efficient dynamic subtractive color filters incorporating a dielectric-loaded aluminum nanowire array, providing a continuum of customized color according to the incident polarization. Dynamic color filtering was realized relying on selective suppression in transmission spectra via plasmonic resonance at a metal-dielectric interface and guided-mode resonance for a metal-clad dielectric waveguide, each occurring at their characteristic wavelengths for transverse-magnetic and electric polarizations, respectively. A broad palette of colors, including cyan, magenta, and yellow, has been attained with high transmission beyond 80%, by tailoring the period of the nanowire array and the incident polarization. Thanks to low cost, high durability, and mass producibility of the aluminum adopted for the proposed devices, they are anticipated to be diversely applied to color displays, holographic imaging, information encoding, and anti-counterfeiting.

  4. 2D and 3D multipactor modeling in dielectric-loaded accelerator structures

    NASA Astrophysics Data System (ADS)

    Sinitsyn, Oleksandr; Nusinovich, Gregory; Antonsen, Thomas

    2010-11-01

    Multipactor (MP) is known as the avalanche growth of the number of secondary electrons emitted from a solid surface exposed to an RF electric field under vacuum conditions. MP is a severe problem in modern rf systems and, therefore, theoretical and experimental studies of MP are of great interest to the researchers working in various areas of physics and engineering. In this work we present results of MP studies in dielectric-loaded accelerator (DLA) structures. First, we show simulation results obtained with the use of the 2D self-consistent MP model (O. V. Sinitsyn, et. al., Phys. Plasmas, vol. 16, 073102 (2009)) and compare those to experimental ones obtained during recent extensive studies of DLA structures performed by Argonne National Laboratory, Naval Research Laboratory, SLAC National Accelerator Laboratory and Euclid TechLabs (C. Jing, et al., IEEE Trans. Plasma Sci., vol. 38, pp. 1354-1360 (2010)). Then we present some new results of 3D analysis of MP which include studies of particle trajectories and studies of MP development at the early stage.

  5. Start current of dielectric-loaded grating in Smith-Purcell radiation

    NASA Astrophysics Data System (ADS)

    Liu, Wenxin; Cao, Miaomiao; Wang, Yong; Li, Ke

    2016-03-01

    In this paper, a three-dimensional dielectric loaded grating (DLG) is proposed for the Smith-Purcell (SP) device. Taking into the considerations of thickness and width of electron beam, the dispersion equation is derived by using field matches method. The complex frequency is obtained by the numerical solution of dispersion equation, in which the imaginary part represents linear growth rate. The impacts of the electron beam filling factor (EBFF) on growth rate are discussed under the condition that the beam current and beam current density are kept as constants, respectively. In addition, the start current for SP oscillator is obtained by using the dispersion relation combined with boundary conditions. The relationship between the start current and other parameters is discussed and compared with the conventional metal grating. The results show that with the increasing of EBFF, the peak growth rate increases rapidly firstly and then decreases slowly, in which the current and current density are kept as constants, respectively. For the SP oscillator, the start current is increased with the shifting up beam voltage, but it is decreased with the improved EBFF, and only it has a slightly increasing trend when EBFF is close to 1. In addition, the start current is decreased with the increasing of relative dielectric constant, which indicates that by introducing DLG, the start current can be effectively reduced. Theoretical results are in good agreement with that of the simulations.

  6. Conductor disc used to suppress spurious mode and enhance electric coupling in a dielectric loaded combline resonator

    NASA Astrophysics Data System (ADS)

    Pholele, T. M.; Chuma, J. M.

    2016-03-01

    The effects of conductor disc in a dielectric loaded combline resonator on its spurious performance, unloaded quality factor (Qu), and coupling coefficients are analysed using a commercial electromagnetic software package CST Microwave Studio (CST MWS). The disc improves the spurious free band but simultaneously deteriorates the Qu. The presence of the disc substantially improves the electric coupling by a factor of 1.891 for an aperture opening of 12 mm, while it has insignificant effect on the magnetic coupling.

  7. Design considerations for a higher-order-mode dielectric-loaded power extractor set for millimeter-wave generation.

    SciTech Connect

    Gai, W.; Liu, W.; Gao, F.; Wong, T.; Jing, C.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs LLC

    2009-10-11

    The design of an electron-beam excited device for millimeter-wave generation is presented. Referred to as a dielectric-loaded power extractor, it is based on the higher-order-mode operation of a dielectric-loaded waveguide. With a matching transition, the unit can deliver power to the output waveguide at one of two frequencies, 20.8 and 35.1 GHz, corresponding to the TM{sub 02} and TM{sub 03} modes, respectively. By properly choosing the thickness of the dielectric lining, both modes are tuned to synchronize with an ultra-relativistic electron beam traversing the unit so that the wakefield generated by the beam is excited at these modes, chosen to be at 20.8 and 35.1 GHz, respectively, both corresponding to a harmonic of the 1.3 GHz operating frequency at an accelerator facility. Power generated in the unintended TM{sub 01} mode is effectively suppressed for bunch train operation by a novel technique. The device consists of a dielectric-loaded decelerating structure and two changeable output couplers to deliver the millimeter-wave power to a standard waveguide. For a drive beam with 50 nC of charge per bunch, power levels of 90.4 and 8.68 MW are expected to be delivered by the device at 20.8 and 35.1 GHz, respectively.

  8. A wearable ECG-HR detector and its application to automatic assist-mode selection of an electrically assisted bicycle.

    PubMed

    Ueno, Akinori; Miyashita, Osamu; Yoshida, Toshiya; Yamamoto, Junichi; Lataire, Philippe

    2011-01-01

    Recently, an electrically assisted bicycle has been widely used in daily life and becomes very popular. The user selects the stepwise assist-mode to determine the assistive torque for pleasurable running. From the viewpoint of improvement of health by exercise, the electrically assisted bicycle can be an exercise machine like a treadmill. The heart rate (HR) is regarded as an indication of exercise load. This paper presents an automatic assist-mode selection system based on the HR of the bicycle user. The HR is obtained from the R-waves measured by the proposed wearable electrocardiograph on the user. The mode-selection system is simply implemented by a personal computer, USB-connected interface, and some electronic switching circuits. The running experiments confirm that the proposed assist-mode selection method has practicability. PMID:22255925

  9. Observation of multipactor suppression in a dielectric-loaded accelerating structure using an applied axial magnetic field

    SciTech Connect

    Jing, C.; Konecny, R.; Antipov, S.; Chang, C.; Gold, S. H.; Schoessow, P.; Kanareykin, A.; Gai, W.

    2013-11-18

    Efforts by a number of institutions to develop a Dielectric-Loaded Accelerating (DLA) structure capable of supporting high gradient acceleration when driven by an external radio frequency source have been ongoing over the past decade. Single surface resonant multipactor has been previously identified as one of the major limitations on the practical application of DLA structures in electron accelerators. In this paper, we report the results of an experiment that demonstrated suppression of multipactor growth in an X-band DLA structure through the use of an applied axial magnetic field. This represents an advance toward the practical use of DLA structures in many accelerator applications.

  10. Multi-nanosecond high power pulse generation at 7.8GHz with a dielectric-loaded power extractor.

    SciTech Connect

    Conde, M..; Gai, W.; Konecny, R.; Liu, W.; Power, J. G.; Gao, F.; Jing, C.; Wong, T.; Yusof, Z.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs LLC; IEEE

    2009-06-01

    Power extraction from charged particle beams is a prospective way to develop future high power radio frequency (RF) sources. We have designed and tested a 7.8 GHz power extractor based on a dielectric-loaded waveguide. Building upon earlier work on single electron bunch tests, 10 ns and 22 ns megawatt-level RF pulses have been generated with trains consisting of 16 electron bunches each, by using a laser splitting-recombination scheme. In addition, 44 MW of peak power has been generated with a train consisting 4 electron bunches. Behaviors of higher-order-modes are also explored.

  11. Observation of multipactor suppression in a dielectric-loaded accelerating structure using an applied axial magnetic field

    NASA Astrophysics Data System (ADS)

    Jing, C.; Chang, C.; Gold, S. H.; Konecny, R.; Antipov, S.; Schoessow, P.; Kanareykin, A.; Gai, W.

    2013-11-01

    Efforts by a number of institutions to develop a Dielectric-Loaded Accelerating (DLA) structure capable of supporting high gradient acceleration when driven by an external radio frequency source have been ongoing over the past decade. Single surface resonant multipactor has been previously identified as one of the major limitations on the practical application of DLA structures in electron accelerators. In this paper, we report the results of an experiment that demonstrated suppression of multipactor growth in an X-band DLA structure through the use of an applied axial magnetic field. This represents an advance toward the practical use of DLA structures in many accelerator applications.

  12. Development of a Dielectric-Loaded Accelerator Test Facility Based on an X-Band Magnicon Amplifier

    SciTech Connect

    Gold, S. H.; Fliflet, A. W.; Kinkead, A. K.; Gai, W.; Power, J. G.; Konecny, R.; Jing, C.; Tantawi, S. G.; Nantista, C. D.; Hu, Y.; Du, X.; Tang, C.; Lin, Y.; Bruce, R. W.; Bruce, R. L.; Lewis, D. III

    2006-01-03

    The Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), are developing a dielectric-loaded accelerator (DLA) test facility powered by the 11.424-GHz magnicon amplifier that was developed jointly by NRL and Omega-P, Inc. Thus far, DLA structures developed by ANL have been tested at the NRL Magnicon Facility without injected electrons, including tests of alumina and magnesium calcium titanate structures at gradients up to {approx}8 MV/m. The next step is to inject electrons in order to build a compact DLA test accelerator. The Accelerator Laboratory of Tsinghua University in Beijing, China has developed a 5-MeV electron injector for the accelerator, and SLAC is developing a means to combine the two magnicon output arms, and to drive the injector and an accelerator section with separate control of the power ratio and relative phase. Also, RWBruce Associates, working with NRL, is developing a means to join ceramic tubes to produce long accelerating sections using a microwave brazing process. The installation and commissioning of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year.

  13. High efficiency in mode-selective frequency conversion.

    PubMed

    Quesada, Nicolás; Sipe, J E

    2016-01-15

    Frequency conversion (FC) is an enabling process in many quantum information protocols. Recently, it has been observed that upconversion efficiencies in single-photon, mode-selective FC are limited to around 80%. In this Letter, we argue that these limits can be understood as time-ordering corrections (TOCs) that modify the joint conversion amplitude of the process. Furthermore, using a simple scaling argument, we show that recently proposed cascaded FC protocols that overcome the aforementioned limitations act as "attenuators" of the TOCs. This observation allows us to argue that very similar cascaded architectures can be used to attenuate TOCs in photon generation via spontaneous parametric downconversion. Finally, by using the Magnus expansion, we argue that the TOCs, which are usually considered detrimental for FC efficiency, can also be used to increase the efficiency of conversion in partially mode-selective FC. PMID:26766715

  14. Contact-free sheet resistance determination of large area graphene layers by an open dielectric loaded microwave cavity

    SciTech Connect

    Shaforost, O.; Wang, K.; Adabi, M.; Guo, Z.; Hanham, S.; Klein, N.; Goniszewski, S.; Gallop, J.; Hao, L.

    2015-01-14

    A method for contact-free determination of the sheet resistance of large-area and arbitrary shaped wafers or sheets coated with graphene and other (semi) conducting ultrathin layers is described, which is based on an open dielectric loaded microwave cavity. The sample under test is exposed to the evanescent resonant field outside the cavity. A comparison with a closed cavity configuration revealed that radiation losses have no significant influence of the experimental results. Moreover, the microwave sheet resistance results show good agreement with the dc conductivity determined by four-probe van der Pauw measurements on a set of CVD samples transferred on quartz. As an example of a practical application, correlations between the sheet resistance and deposition conditions for CVD graphene transferred on quartz wafers are described. Our method has a high potential as measurement standard for contact-free sheet resistance measurement and mapping of large area graphene samples.

  15. Contact-free sheet resistance determination of large area graphene layers by an open dielectric loaded microwave cavity

    NASA Astrophysics Data System (ADS)

    Shaforost, O.; Wang, K.; Goniszewski, S.; Adabi, M.; Guo, Z.; Hanham, S.; Gallop, J.; Hao, L.; Klein, N.

    2015-01-01

    A method for contact-free determination of the sheet resistance of large-area and arbitrary shaped wafers or sheets coated with graphene and other (semi) conducting ultrathin layers is described, which is based on an open dielectric loaded microwave cavity. The sample under test is exposed to the evanescent resonant field outside the cavity. A comparison with a closed cavity configuration revealed that radiation losses have no significant influence of the experimental results. Moreover, the microwave sheet resistance results show good agreement with the dc conductivity determined by four-probe van der Pauw measurements on a set of CVD samples transferred on quartz. As an example of a practical application, correlations between the sheet resistance and deposition conditions for CVD graphene transferred on quartz wafers are described. Our method has a high potential as measurement standard for contact-free sheet resistance measurement and mapping of large area graphene samples.

  16. Transverse mode selection in laser resonators using volume Bragg gratings

    NASA Astrophysics Data System (ADS)

    Anderson, Brian; Venus, George; Ott, Daniel; Divliansky, Ivan; Dawson, Jay W.; Drachenberg, Derrek R.; Messerly, Mike J.; Pax, Paul H.; Tassano, John B.; Glebov, Leonid

    2014-06-01

    Power scaling of high power laser resonators is limited due to several nonlinear effects. Scaling to larger mode areas can offset these effects at the cost of decreased beam quality, limiting the brightness that can be achieved from the multi-mode system. In order to improve the brightness from such multi-mode systems, we present a method of transverse mode selection utilizing volume Bragg gratings (VBGs) as an angular filter, allowing for high beam quality from large mode area laser resonators. An overview of transverse mode selection using VBGs is given, with theoretical models showing the effect of the angular selectivity of transmitting VBGs on the resonator modes. Applications of this ideology to the design of laser resonators, with cavity designs and experimental results presented for three types of multimode solid state lasers: a Nd:YVO4 laser with 1 cm cavity length and 0.8 mm diameter beam with an M2 of 1.1, a multimode diode with diffraction limited far field divergence in the slow axis, and a ribbon fiber laser with 13 cores showing M2 improved from 11.3 to 1.5.

  17. Large-signal characteristics of a wide-band dielectric-loaded gyro-TWT amplifier

    SciTech Connect

    Leou, K.C.; McDermott, D.B.; Luhmann, N.C. Jr.

    1996-06-01

    The bandwidth of a gyrotron traveling wave amplifier (gyro-TWT) has been significantly increased by partially filling the interaction waveguide with dielectric to reduce the circuit`s dispersion. The proof-of-principle experiment was designed for X-band, and employs the fundamental mode of rectangular waveguide loaded with dielectric slabs along the narrow sidewalls. The amplifier yields a peak output power of 55 kW with 11% efficiency, 27 DB saturated gain, and an unprecedented untapered gyro-TWT constant-drive bandwidth of 11% and saturated bandwidth exceeding 14%. The single-stage amplifier is completely zero-drive stable. The 95-kV 5-A electron beam was produced by a single-anode magnetron injection gun with {upsilon}{sub {perpendicular}}/{upsilon}{sub z} = 0.6, as determined by the EGUN code, and {Delta}{upsilon}{sub z}/{upsilon}{sub z} = 4%, determined as the best fit to the gyro-TWT large-signal simulation data. Simulation studies predict that by lowering the velocity spread to {Delta}{upsilon}{sub z}/{upsilon}{sub z} = 2%, the amplifier performance will be further enhanced to a constant-drive bandwidth of 20% with 15% efficiency.

  18. Mode Selection for a Single-Frequency Fiber Laser

    NASA Technical Reports Server (NTRS)

    Liu, Jian

    2010-01-01

    A superstructured fiber-grating-based mode selection filter for a single-frequency fiber laser eliminates all free-space components, and makes the laser truly all-fiber. A ring cavity provides for stable operations in both frequency and power. There is no alignment or realignment required. After the fibers and components are spliced together and packaged, there is no need for specially trained technicians for operation or maintenance. It can be integrated with other modules, such as telescope systems, without extra optical alignment due to the flexibility of the optical fiber. The filter features a narrow line width of 1 kHz and side mode suppression ratio of 65 dB. It provides a high-quality laser for lidar in terms of coherence length and signal-to-noise ratio, which is 20 dB higher than solid-state or microchip lasers. This concept is useful in material processing, medical equipment, biomedical instrumentation, and optical communications. The pulse-shaping fiber laser can be directly used in space, airborne, and satellite applications including lidar, remote sensing, illuminators, and phase-array antenna systems.

  19. Temperature insensitive mass sensing of mode selected phononic crystal cavity

    NASA Astrophysics Data System (ADS)

    Li, Peng; Li, Feng; Liu, Yongshun; Shu, Fengfeng; Wu, Junfeng; Wu, Yihui

    2015-12-01

    Phononic crystal cavities with high quality (Q) factors are attractive in both signal processing and sensing applications. In this paper, 2D phononic crystal point defect cavities are fabricated on silicon slabs by micro electromechanical system (MEMS) technologies. An electrode design method is proposed to enhance displacements of the point defect modes. Then the method is applied to design MEMS resonators with different port numbers, among which Q factor as high as 21 300 is obtained in air. Multiport resonators with transmission measurements are proved to be advantageous over one-port resonators with impedance measurements in frequency resolution. A temperature insensitive resonant mass sensor is designed based on a two-port resonator. Two defect modes with strong responses in the two-port resonator are combined to compensate environmental temperature interference. The temperature compensation experiment reveals that temperature interference is effectively compensated from mass measurement and the mass sensitivity of the sensor is 5.4 Hz ng-1. The conclusion of mode selection or sensing mechanism will help to design resonators or sensors with high performances.

  20. Fast response and low power consumption 1×2 thermo-optic switch based on dielectric-loaded surface plasmon polariton waveguides

    NASA Astrophysics Data System (ADS)

    Qi, Zhipeng; Hu, Guohua; Yun, Binfeng; Zhang, Xiong; Cui, Yiping

    2016-08-01

    In this paper, we present a 1 × 2 thermo-optic (TO) switch based on the integration of the dielectric-loaded surface plasmon polariton (SPP) waveguides with the silicon nanowires. Liquid-curable fluorinated resin (LFR) made of perfluorinated polymer was adopted as the ridge, which has a TO coefficient twice more than that of polymethyl methacrylate, leading to a significant decrease in the power consumption. It was shown that the response time of the dielectric-loaded SPP waveguide could be improved through optimizing the dimensions of the LFR polymer ridge without loss of relative high figure of merit and large confinement factor. Performance characteristics of such a 1 × 2 TO switch operating at a telecom wavelength of 1550 nm was investigated theoretically from the analysis of both heat and optical fields. The results reveal that a switching power as low as 7 mW and an extremely short switching time (with rise time of 3 μs and fall time of 6.7 μs) could be achieved with the proposed dielectric-loaded SPP-based 1 × 2 TO switch. In addition, the crosstalk could be enhanced to at least 40 dB with the applied power of 7 mW at the wavelength of 1550 nm, and it could be retained to be above 20 dB in the wavelength spectrum of 1500-1600 nm during the on/off state.

  1. Mode-selective control of the crystal lattice.

    PubMed

    Först, M; Mankowsky, R; Cavalleri, A

    2015-02-17

    CONSPECTUS: Driving phase changes by selective optical excitation of specific vibrational modes in molecular and condensed phase systems has long been a grand goal for laser science. However, phase control has to date primarily been achieved by using coherent light fields generated by femtosecond pulsed lasers at near-infrared or visible wavelengths. This field is now being advanced by progress in generating intense femtosecond pulses in the mid-infrared, which can be tuned into resonance with infrared-active crystal lattice modes of a solid. Selective vibrational excitation is particularly interesting in complex oxides with strong electronic correlations, where even subtle modulations of the crystallographic structure can lead to colossal changes of the electronic and magnetic properties. In this Account, we summarize recent efforts to control the collective phase state in solids through mode-selective lattice excitation. The key aspect of the underlying physics is the nonlinear coupling of the resonantly driven phonon to other (Raman-active) modes due to lattice anharmonicities, theoretically discussed as ionic Raman scattering in the 1970s. Such nonlinear phononic excitation leads to rectification of a directly excited infrared-active mode and to a net displacement of the crystal along the coordinate of all anharmonically coupled modes. We present the theoretical basis and the experimental demonstration of this phenomenon, using femtosecond optical spectroscopy and ultrafast X-ray diffraction at a free electron laser. The observed nonlinear lattice dynamics is shown to drive electronic and magnetic phase transitions in many complex oxides, including insulator-metal transitions, charge/orbital order melting and magnetic switching in manganites. Furthermore, we show that the selective vibrational excitation can drive high-TC cuprates into a transient structure with enhanced superconductivity. The combination of nonlinear phononics with ultrafast crystallography at

  2. Layered mode selection logic control for border security

    NASA Astrophysics Data System (ADS)

    Born, T.; Ferrer, G.; Wright, A. M.; Wright, A. B.

    2007-04-01

    Challenges in border security may be resolved through a team of autonomous mobile robots configured as a flexible sensor array. The robots will have a prearranged formation along a section of a border, and each robot will attempt to maintain a uniform distance with its nearest neighbors. The robots will carry sensor packages which can detect a signature that is representative of a human (for instance, a thermal signature). When a robot detects an intruder, it will move away such that it attempts to maintain a constant distance from the intruder and move away from the border (i.e. into its home territory). As the robot moves away from the border, its neighbors will move away from the border to maintain a uniform distance with the moving robot and with their fixed neighbors. The pattern of motion in the team of robots can be identified, either algorithmically by a computer or by a human monitor of a display. Unique patterns are indicative of animal movement, human movement, and mass human movement. To realize such a scheme, a new control architecture must be developed. This architecture must be fault tolerant to sensor and manipulator failures, scalable in number of agents, and adaptable to different robotic base platforms (for instance, a UGV may be appropriate at the southern border and a UAV may be appropriate at the northern border). The Central Arkansas Robotics Consortium has developed an architecture, called Layered Mode Selection Logic (LMSL), which addresses all of these concerns. The overall LMSL scheme as applied to a multi-agent flexible sensor array is described in this paper.

  3. Improved Frame Mode Selection for AMR-WB+ Based on Decision Tree

    NASA Astrophysics Data System (ADS)

    Kim, Jong Kyu; Kim, Nam Soo

    In this letter, we propose a coding mode selection method for the AMR-WB+ audio coder based on a decision tree. In order to reduce computation while maintaining good performance, decision tree classifier is adopted with the closed loop mode selection results as the target classification labels. The size of the decision tree is controlled by pruning, so the proposed method does not increase the memory requirement significantly. Through an evaluation test on a database covering both speech and music materials, the proposed method is found to achieve a much better mode selection accuracy compared with the open loop mode selection module in the AMR-WB+.

  4. Optoelectronic optimization of mode selective converter based on liquid crystal on silicon

    NASA Astrophysics Data System (ADS)

    Wang, Yongjiao; Liang, Lei; Yu, Dawei; Fu, Songnian

    2016-03-01

    We carry out comprehensive optoelectronic optimization of mode selective converter used for the mode division multiplexing, based on liquid crystal on silicon (LCOS) in binary mode. The conversion error of digital-to-analog (DAC) is investigated quantitatively for the purpose of driving the LCOS in the application of mode selective conversion. Results indicate the DAC must have a resolution of 8-bit, in order to achieve high mode extinction ratio (MER) of 28 dB. On the other hand, both the fast axis position error of half-wave-plate (HWP) and rotation angle error of Faraday rotator (FR) have negative influence on the performance of mode selective conversion. However, the commercial products provide enough angle error tolerance for the LCOS-based mode selective converter, taking both of insertion loss (IL) and MER into account.

  5. Harmonics generation of a terahertz wakefield free-electron laser from a dielectric loaded waveguide excited by a direct current electron beam.

    PubMed

    Li, Weiwei; Lu, Yalin; He, Zhigang; Jia, Qika; Wang, Lin

    2016-06-01

    We propose to generate high-power terahertz (THz) radiation from a cylindrical dielectric loaded waveguide (DLW) excited by a direct-current electron beam with the harmonics generation method. The DLW supports a discrete set of modes that can be excited by an electron beam passing through the structure. The interaction of these modes with the co-propagating electron beam results in micro-bunching and the coherent enhancement of the wakefield radiation, which is dominated by the fundamental mode. By properly choosing the parameters of DLW and beam energy, the high order modes can be the harmonics of the fundamental one; thus, high frequency radiation corresponding to the high order modes will benefit from the dominating bunching process at the fundamental eigenfrequency and can also be coherently excited. With the proposed method, high power THz radiation can be obtained with an easily achievable electron beam and a large DLW structure. PMID:27244388

  6. Mode-selective quantization and multimodal effective models for spherically layered systems

    NASA Astrophysics Data System (ADS)

    Dzsotjan, D.; Rousseaux, B.; Jauslin, H. R.; des Francs, G. Colas; Couteau, C.; Guérin, S.

    2016-08-01

    We propose a geometry-specific, mode-selective quantization scheme in coupled field-emitter systems which makes it easy to include material and geometrical properties, and intrinsic losses, as well as the positions of an arbitrary number of quantum emitters. The method is presented through the example of a spherically symmetric, nonmagnetic, arbitrarily layered system. We follow it up by a framework to project the system on simpler, effective cavity QED models. Maintaining a well-defined connection to the original quantization, we derive the emerging effective quantities from the full, mode-selective model in a mathematically consistent way. We discuss the uses and limitations of these effective models.

  7. Transversal and longitudinal mode selections in double-corrugation coaxial slow-wave devices

    NASA Astrophysics Data System (ADS)

    Ge, Xingjun; Zhong, Huihuang; Qian, Baoliang; Liu, Lie; Liu, Yonggui; Li, Limin; Shu, Ting; Zhang, Jiande

    2009-06-01

    To reduce the dimensions of relativistic backward wave oscillators (RBWOs) operating in the low frequency regime of less than 2 GHz, the theory of transversal and longitudinal mode selections are introduced in this paper. The transversal mode selection is achieved using the property of "surface wave" of the coaxial slow-wave structure (SWS) to excite the quasi transverse electromagnetic (quasi-TEM) mode without the higher transverse magnetic (TM) modes and it is proved that the coaxial SWS may decrease the transversal dimension of the SWS sections. In addition, the S-parameter method is employed to investigate the longitudinal resonant characteristic of the finite-length SWS, and the scheme of longitudinal mode selection is put forward. It is proposed that the introduction of a well-designed coaxial extractor to slow-wave devices can help to achieve the longitudinal mode selection and reduce the period number of the SWS, which not only can make the devices more compact, but also can avoid the destructive competition between various longitudinal modes, therefore can enhance the efficiency and stabilize the frequency. To sum up, the physical mechanisms of transversal and longitudinal mode selections ensure that the microwave is produced with a single mode and a narrow band. Based on the above discussion, a compact L-band coaxial RBWO is investigated and optimized in detail with the particle-in-cell KARAT code (V. P. Tarakanov, Berkeley Research Associates, Inc., 1992). In simulation, the L-band coaxial RBWO, driven by a 700 kV, 11 kA electron beam, comes to a nonlinear steady state in 20 ns. High-power microwave of quasi-TEM mode is generated with an average power of 2.66 GW, a frequency of 1.6 GHz, and power conversion efficiency of 34.5% in durations of 30-60 ns.

  8. Transversal and longitudinal mode selections in double-corrugation coaxial slow-wave devices

    SciTech Connect

    Ge Xingjun; Zhong Huihuang; Qian Baoliang; Liu Lie; Liu Yonggui; Li Limin; Shu Ting; Zhang Jiande

    2009-06-15

    To reduce the dimensions of relativistic backward wave oscillators (RBWOs) operating in the low frequency regime of less than 2 GHz, the theory of transversal and longitudinal mode selections are introduced in this paper. The transversal mode selection is achieved using the property of ''surface wave'' of the coaxial slow-wave structure (SWS) to excite the quasi transverse electromagnetic (quasi-TEM) mode without the higher transverse magnetic (TM) modes and it is proved that the coaxial SWS may decrease the transversal dimension of the SWS sections. In addition, the S-parameter method is employed to investigate the longitudinal resonant characteristic of the finite-length SWS, and the scheme of longitudinal mode selection is put forward. It is proposed that the introduction of a well-designed coaxial extractor to slow-wave devices can help to achieve the longitudinal mode selection and reduce the period number of the SWS, which not only can make the devices more compact, but also can avoid the destructive competition between various longitudinal modes, therefore can enhance the efficiency and stabilize the frequency. To sum up, the physical mechanisms of transversal and longitudinal mode selections ensure that the microwave is produced with a single mode and a narrow band. Based on the above discussion, a compact L-band coaxial RBWO is investigated and optimized in detail with the particle-in-cell KARAT code (V. P. Tarakanov, Berkeley Research Associates, Inc., 1992). In simulation, the L-band coaxial RBWO, driven by a 700 kV, 11 kA electron beam, comes to a nonlinear steady state in 20 ns. High-power microwave of quasi-TEM mode is generated with an average power of 2.66 GW, a frequency of 1.6 GHz, and power conversion efficiency of 34.5% in durations of 30-60 ns.

  9. Single-mode lasers and parity-time symmetry broken gratings based on active dielectric-loaded long-range surface plasmon polariton waveguides.

    PubMed

    Hahn, Choloong; Song, Seok Ho; Oh, Cha Hwan; Berini, Pierre

    2015-07-27

    Single-mode distributed feedback laser structures and parity-time symmetry broken grating structures based on dielectric-loaded long-range surface plasmon polariton waveguides are proposed. The structures comprise a thin Ag stripe on an active polymer bottom cladding with an active polymer ridge. The active polymer assumed is PMMA doped with IR140 dye providing optical gain at near infrared wavelengths. Cutoff top ridge dimensions (thickness and width) are calculated using a finite element method and selected to guarantee single-mode operation of the laser. Several parameters such as the threshold number of periods and the lasing wavelength are determined using the transfer matrix method. A related structure based on two pairs of waveguides of two widths, which have the same imaginary part but different real part of effective index, arranged within one grating period, is proposed as an active grating operating at the threshold for parity-time symmetry breaking (i.e., operating at an exceptional point). Such "exceptional point" gratings produce ideal reflectance asymmetry as demonstrated via transfer matrix computations. PMID:26367652

  10. Guided wave mode selection for inhomogeneous elastic waveguides using frequency domain finite element approach.

    PubMed

    Chillara, Vamshi Krishna; Ren, Baiyang; Lissenden, Cliff J

    2016-04-01

    This article describes the use of the frequency domain finite element (FDFE) technique for guided wave mode selection in inhomogeneous waveguides. Problems with Rayleigh-Lamb and Shear-Horizontal mode excitation in isotropic homogeneous plates are first studied to demonstrate the application of the approach. Then, two specific cases of inhomogeneous waveguides are studied using FDFE. Finally, an example of guided wave mode selection for inspecting disbonds in composites is presented. Identification of sensitive and insensitive modes for defect inspection is demonstrated. As the discretization parameters affect the accuracy of the results obtained from FDFE, effect of spatial discretization and the length of the domain used for the spatial fast Fourier transform are studied. Some recommendations with regard to the choice of the above parameters are provided. PMID:26746160

  11. Realization of Plasmonic Microcavity with Full Transverse and Longitudinal Mode Selection

    NASA Astrophysics Data System (ADS)

    Liu, Ju; Chen, Yue-Gang; Gan, Lin; Xiao, Ting-Hui; Li, Zhi-Yuan

    2016-06-01

    Surface plasmon polaritons (SPPs) manipulation is of vital importance to construct ultracompact integrated micro/nano-optical devices and systems. Here we report the design, fabrication, and characterization of a SPP microcavity with full transverse and longitudinal mode selection and control on the surface of gold film. The designed microcavity supports the fundamental and first-order transverse modes of Gaussian mode beam with controllable longitudinal modes, respectively. The transverse mode is determined by two holographic mirrors made from deliberately designed groove patterns via the surface electromagnetic wave holography methodology, while the longitudinal mode is determined by the length of cavity. Both numerical simulations and leaky-wave SPP mode observations confirm the realization of full mode selection in the fabricated cavity. Our work opens up a powerful way to fully explore longitudinal and transverse mode control in SPP microcavities, which will be beneficial for light-matter interaction enhancement, construction of novel SPP nanolaser and microlaser, optical sensing, and optical information processing.

  12. An Innovative Structural Mode Selection Methodology: Application for the X-33 Launch Vehicle Finite Element Model

    NASA Technical Reports Server (NTRS)

    Hidalgo, Homero, Jr.

    2000-01-01

    An innovative methodology for determining structural target mode selection and mode selection based on a specific criterion is presented. An effective approach to single out modes which interact with specific locations on a structure has been developed for the X-33 Launch Vehicle Finite Element Model (FEM). We presented Root-Sum-Square (RSS) displacement method computes resultant modal displacement for each mode at selected degrees of freedom (DOF) and sorts to locate modes with highest values. This method was used to determine modes, which most influenced specific locations/points on the X-33 flight vehicle such as avionics control components, aero-surface control actuators, propellant valve and engine points for use in flight control stability analysis and for flight POGO stability analysis. Additionally, the modal RSS method allows for primary or global target vehicle modes to also be identified in an accurate and efficient manner.

  13. Mode-selective optical packet switching in mode-division multiplexing networks.

    PubMed

    Diamantopoulos, N P; Hayashi, M; Yoshida, Y; Maruta, A; Maruyama, R; Kuwaki, N; Takenaga, K; Uemura, H; Matsuo, S; Kitayama, K

    2015-09-01

    A novel mode-selective optical packet switching, based on mode-multiplexers/demultiplexers and multi-port optical micro-electro-mechanical systems (MEMS) switches, has been proposed and experimentally demonstrated. The experimental demonstration was performed using the LP(01), LP(11a) and LP(11b) modes of a 30-km long mode-division multiplexed few-mode fiber link, utilizing 40 Gb/s, 16-QAM signals. PMID:26368463

  14. Advanced LSI-based amperometric sensor array with light-shielding structure for effective removal of photocurrent and mode selectable function for individual operation of 400 electrodes.

    PubMed

    Inoue, Kumi Y; Matsudaira, Masahki; Nakano, Masanori; Ino, Kosuke; Sakamoto, Chika; Kanno, Yusuke; Kubo, Reyushi; Kunikata, Ryota; Kira, Atsushi; Suda, Atsushi; Tsurumi, Ryota; Shioya, Toshihito; Yoshida, Shinya; Muroyama, Masanori; Ishikawa, Tomohiro; Shiku, Hitoshi; Satoh, Shiro; Esashi, Masayoshi; Matsue, Tomokazu

    2015-02-01

    We have developed a large-scale integrated (LSI) complementary metal-oxide semiconductor (CMOS)-based amperometric sensor array system called "Bio-LSI" as a platform for electrochemical bio-imaging and multi-point biosensing with 400 measurement points. In this study, we newly developed a Bio-LSI chip with a light-shield structure and a mode-selectable function with the aim of extending the application range of Bio-LSI. The light shield created by the top metal layer of the LSI chip significantly reduces the noise generated by the photocurrent, whose value is less than 1% of the previous Bio-LSI without the light shield. The mode-selectable function enables the individual operation of 400 electrodes in off, electrometer, V1, and V2 mode. The off-mode cuts the electrode from the electric circuit. The electrometer-mode reads out the electrode potential. The V1-mode and the V2-mode set the selected sensor electrode at two different independent voltages and read out the current. We demonstrated the usefulness of the mode-selectable function. First, we displayed a dot picture based on the redox reactions of 2.0 mM ferrocenemethanol at 400 electrodes by applying two different independent voltages using the V1 and V2 modes. Second, we carried out a simultaneous detection of O2 and H2O2 using the V1 and V2 modes. Third, we used the off and V1 modes for the modification of the osmium-polyvinylpyridine gel polymer containing horseradish peroxidase (Os-HRP) at the selected electrodes, which act as sensors for H2O2. These results confirm that the advanced version of Bio-LSI is a promising tool that can be applied to a wide range of analytical fields. PMID:25483361

  15. Learning guide for the terminal configured vehicle advanced guidance and control system mode select panel

    NASA Technical Reports Server (NTRS)

    Anderson, M. A.; Callahan, R.

    1981-01-01

    This learning guide is designed to assist pilots in taking the PLATO presimulator training course on the advanced guidance and control system mode select panel. The learning guide is divided into five sections. The first section, the introduction, presents the course goals, prerequisites, definition of PLATO activities, and a suggested approach to completing the course. The remaining four sections present the purpose, learning activities and summary of each lesson of the AGCS PLATO course, which consists of (1) AGCS introduction; (2) lower order modes; (3) higher order modes; and (4) an arrival route exercise.

  16. An approach of waveguide mode selection based on the thin-film spatial filters

    NASA Astrophysics Data System (ADS)

    Luo, Zhaoming; Chen, Min; Liu, Jing; Lei, Dajun

    2016-04-01

    A novel approach is presented for waveguide mode selection by using thin-film spatial filters embedded in multimode waveguides. The waveguide modes are allowed to pass through the spatial filters if and when their mode angles fall within the angle-domain bandwidth of the filters. Consequently the waveguide modes are selectable with varied angle-domain bandwidth of the spatial filters. This approach is relatively simple, cost-effective and features good suppression effect of high-order modes, and is suitable for high-power laser systems.

  17. Strongly enhanced mode selection in a thin dielectric-coated layered microcavity laser

    NASA Astrophysics Data System (ADS)

    Moon, Hee-Jong; Kang, Dong-Yun

    2007-06-01

    Strong mode selection through an enhanced interferential coupling effect was observed in a thin dielectric-coated layered cylindrical microcavity laser. The strong coupling effect was induced owing to an enhanced reflectivity of around 50% at the dielectric-coated inner boundary of a fused silica capillary filled with a dye-doped liquid. At an optimized coating thickness of about 0.4 μm, the lasing peaks appeared only at the wavelengths corresponding to the constructive interference condition, whereas those from a bare capillary were weakly modulated.

  18. Mode selection and resonator design studies of a 95 GHz, 100 kW, CW gyrotron

    SciTech Connect

    Vamshi Krishna, P.; Kartikeyan, M.V. E-mail: kartik@iitr.ernet.in; Thumm, M.

    2011-07-01

    In this paper, the mode selection procedure leading to the design and the cavity resonator design studies of a 95 GHz, 100 kW, CW Gyrotron will be presented, such a gyrotron will be used for specific ECRH/ECRIS applications. In this course all the suitable modes with design constraints within the limits of design goals are considered and finally the TE{sub 10.4} mode is chosen as the operating mode which is suitable for the design. Design constraints are carefully investigated, and starting currents are computed. (author)

  19. Design of a spin-wave majority gate employing mode selection

    SciTech Connect

    Klingler, S. Pirro, P.; Brächer, T.; Leven, B.; Hillebrands, B.; Chumak, A. V.

    2014-10-13

    The design of a microstructured, fully functional spin-wave majority gate is presented and studied using micromagnetic simulations. This all-magnon logic gate consists of three-input waveguides, a spin-wave combiner, and an output waveguide. In order to ensure the functionality of the device, the output waveguide is designed to perform spin-wave mode selection. We demonstrate that the gate evaluates the majority of the input signals coded into the spin-wave phase. Moreover, the all-magnon data processing device is used to perform logic AND-, OR-, NAND-, and NOR- operations.

  20. Reflectionless compact plasmonic waveguide mode converter by using a mode-selective cavity.

    PubMed

    Kim, Joonsoo; Lee, Seung-Yeol; Park, Hyeonsoo; Lee, Kyookeun; Lee, Byoungho

    2015-04-01

    A compact transmissive plasmonic waveguide mode converter which aims for the elimination of reflection and transmission of unconverted mode is proposed. The proposed scheme exploits a cavity formed by mode selective mirrors, which only allows two output modes: the transmission of the target mode and the reflection of the input mode. By appropriately tuning cavity lengths, the reflection of the input mode can also be suppressed to near zero by destructive interference, thereby all the residual outgoing modes are suppressed. The proposed device might be useful in the design of integrated photonic system since it relaxes the problem of unwanted reflection. PMID:25968736

  1. Mode selectivity study of vertical-cavity surface-emitting lasers

    SciTech Connect

    Liu, G.; Seurin, J.; Chuang, S.L.; Babic, D.I.; Corzine, S.W.; Tan, M.; Barnes, D.C.; Tiouririne, T.N.

    1998-08-01

    Mode selectivity of an air-post index-guided vertical-cavity surface-emitting laser structure operating at 1550 nm is investigated using a full-vector Maxwell-equation solver with a finite-difference time-domain method. The resonance wavelengths, quality factors, and spatial field distributions are calculated for the three lowest-order modes. Transverse-mode competition is quantitatively described as a function of the cavity size and the pillar etch depth. {copyright} {ital 1998 American Institute of Physics.}

  2. Realization of Plasmonic Microcavity with Full Transverse and Longitudinal Mode Selection

    PubMed Central

    Liu, Ju; Chen, Yue-Gang; Gan, Lin; Xiao, Ting-Hui; Li, Zhi-Yuan

    2016-01-01

    Surface plasmon polaritons (SPPs) manipulation is of vital importance to construct ultracompact integrated micro/nano-optical devices and systems. Here we report the design, fabrication, and characterization of a SPP microcavity with full transverse and longitudinal mode selection and control on the surface of gold film. The designed microcavity supports the fundamental and first-order transverse modes of Gaussian mode beam with controllable longitudinal modes, respectively. The transverse mode is determined by two holographic mirrors made from deliberately designed groove patterns via the surface electromagnetic wave holography methodology, while the longitudinal mode is determined by the length of cavity. Both numerical simulations and leaky-wave SPP mode observations confirm the realization of full mode selection in the fabricated cavity. Our work opens up a powerful way to fully explore longitudinal and transverse mode control in SPP microcavities, which will be beneficial for light-matter interaction enhancement, construction of novel SPP nanolaser and microlaser, optical sensing, and optical information processing. PMID:27273163

  3. Realization of Plasmonic Microcavity with Full Transverse and Longitudinal Mode Selection.

    PubMed

    Liu, Ju; Chen, Yue-Gang; Gan, Lin; Xiao, Ting-Hui; Li, Zhi-Yuan

    2016-01-01

    Surface plasmon polaritons (SPPs) manipulation is of vital importance to construct ultracompact integrated micro/nano-optical devices and systems. Here we report the design, fabrication, and characterization of a SPP microcavity with full transverse and longitudinal mode selection and control on the surface of gold film. The designed microcavity supports the fundamental and first-order transverse modes of Gaussian mode beam with controllable longitudinal modes, respectively. The transverse mode is determined by two holographic mirrors made from deliberately designed groove patterns via the surface electromagnetic wave holography methodology, while the longitudinal mode is determined by the length of cavity. Both numerical simulations and leaky-wave SPP mode observations confirm the realization of full mode selection in the fabricated cavity. Our work opens up a powerful way to fully explore longitudinal and transverse mode control in SPP microcavities, which will be beneficial for light-matter interaction enhancement, construction of novel SPP nanolaser and microlaser, optical sensing, and optical information processing. PMID:27273163

  4. An Experimental Investigation of Flow Mode Selection in a Conical Taylor-Couette System

    NASA Astrophysics Data System (ADS)

    Noui-Mehidi, Mohamed Nabil; Ohmura, Naoto; Kataoka, Kunio

    Transitions of viscous flow between coaxial conical cylinders with the inner one rotating and the outer one at rest were investigated to reveal mode selection of the first instabilities with the aid of flow visualization and spectral analysis. The rotational velocity of the inner conical cylinder was linearly accelerated from rest until reaching its final speed. The different observed states were successfully distinguished by their dependency on the acceleration rate β in the investigated range of Taylor number Ta. Transitions between states were determined as functions of β and Ta by fixing the Taylor number and varying the acceleration rate in the range 0.01-1.5 rad/s2. Observed states were classified into: first toroidal vortices (FTV), helical motion (HMV), upward travelling vortices (UTV), steady Taylor vortices (TVF) and wavy vortices (WVF). Modes of six pairs of Taylor vortices (6TVF), seven pairs (7TVF) and eight pairs (8TVF) were observed at the same Ta and different β. Steady Taylor vortices and wavy vortices were also observed when β increased at the same Ta. The spectral analysis indicated that the states HMV and WVF have constant ratios between the characteristic frequencies and the frequency of rotation of the inner conical cylinder, while in UTV the ratio decreases with increasing Ta. The mode selection diagram in the (Ta,β) plane has no regular form with regard to the zones delimiting the different observed states.

  5. High-power radio frequency pulse generation and extration based on wakefield excited by an intense charged particle beam in dielectric-loaded waveguides.

    SciTech Connect

    Gao, F.; High Energy Physics; Illinois Inst. of Tech

    2009-07-24

    Power extraction using a dielectric-loaded (DL) waveguide is a way to generate high-power radio frequency (RF) waves for future particle accelerators, especially for two-beam-acceleration. In a two-beam-acceleration scheme, a low-energy, high-current particle beam is passed through a deceleration section of waveguide (decelerator), where the power from the beam is partially transferred to trailing electromagnetic waves (wakefields); then with a properly designed RF output coupler, the power generated in the decelerator is extracted to an output waveguide, where finally the power can be transmitted and used to accelerate another usually high-energy low-current beam. The decelerator, together with the RF output coupler, is called a power extractor. At Argonne Wakefield Accelerator (AWA), we designed a 7.8GHz power extractor with a circular DL waveguide and tested it with single electron bunches and bunch trains. The output RF frequency (7.8GHz) is the sixth harmonic of the operational frequency (1.3GHz) of the electron gun and the linac at AWA. In single bunch excitation, a 1.7ns RF pulse with 30MW of power was generated by a single 66nC electron bunch passing through the decelerator. In subsequent experiments, by employing different splitting-recombining optics for the photoinjector laser, electron bunch trains were generated and thus longer RF pulses could be successfully generated and extracted. In 16-bunch experiments, 10ns and 22ns RF pulses have been generated and extracted; and in 4-bunch experiments, the maximum power generated was 44MW with 40MW extracted. A 26GHz DL power extractor has also been designed to test this technique in the millimeter-wave range. A power level of 148MW is expected to be generated by a bunch train with a bunch spacing of 769ps and bunch charges of 20nC each. The arrangement for the experiment is illustrated in a diagram. Higher-order-mode (HOM) power extraction has also been explored in a dual-frequency design. By using a bunch

  6. Measuring circuit

    DOEpatents

    Sun, Shan C.; Chaprnka, Anthony G.

    1977-01-11

    An automatic gain control circuit functions to adjust the magnitude of an input signal supplied to a measuring circuit to a level within the dynamic range of the measuring circuit while a log-ratio circuit adjusts the magnitude of the output signal from the measuring circuit to the level of the input signal and optimizes the signal-to-noise ratio performance of the measuring circuit.

  7. Coherence properties of tunable solid-state pulsed lasers with mode selection

    SciTech Connect

    Vaitkus, Y.; Gaubas, E.; Yarashyunas, K.

    1981-06-01

    The temporal coherence of the output from tunable solid-state pulsed lasers has been studied in the commerical version of such a laser and after selection of longitudinal and transverse modes. The selection efficiency was determined by the method of light self-diffraction by dynamic gratings. The results show that the mode selection leads to single-frequency operation of the laser, characterized by an increase in the coherence length from 0.2 to 2 m and by an increase in the overall degree of coherence by a factor of 5--8. There is a good reproducibility of the pulses in terms of the intensity at the wavelength 1064 nm.

  8. A fiber-integrated optical component fabricated via photopolymerization: Mode-selective grating coupler

    NASA Astrophysics Data System (ADS)

    Sümer, Can; Dinleyici, M. Salih

    2013-11-01

    We demonstrate a mode-selective directional coupler based on a grating structure, which is fabricated by laser direct-writing on a photopolymer thin film. The device is implemented on the flat planar surface of the D-Fiber, enabling fiber integration, where an Acrylamide/Polyvinyl Alcohol based photopolymer material is used in the fabrication of the device. While the refractive index modulation properties of the polymer material are well known, surface relief and corrugation properties due to photopolymerization are investigated in this study. Theoretical model of the device is presented together with the optimization and simulation results of the final device; experimental results have been found to be in good agreement with simulations.

  9. Role of magnetic fluctuations in mode selection of magnetically driven instabilities

    SciTech Connect

    Dan, Jia-Kun Ren, Xiao-Dong; Huang, Xian-Bin; Ouyang, Kai; Chen, Guang-Hua

    2014-12-15

    The influences of magnetic fluctuations on quasiperiodic structure formation and fundamental wavelength selection of the instability have been studied using two 25-μm-diameter tungsten wires on a 100  ns rise time, 220 kA pulsed power facility. Two different load configurations were adopted to make end surfaces of electrodes approximately satisfy reflecting and absorbing boundary conditions, respectively. The experimental results that the fundamental wavelength in the case of absorbing boundary condition is about one half of that in the case of reflecting boundary condition have demonstrated that magnetic fluctuations appear to play a key role in mode selection of magnetically driven instabilities. The dominant wavelength should be proportional to magnetic field and inversely proportional to square root of mass density, provided that the magnetosonic wave propagating perpendicular to magnetic fields provides a leading candidate for magnetic fluctuations. Therefore, magnetic fluctuation is one of the three key perturbations, along with surface contaminants and surface roughness, that seeds magnetically driven instabilities.

  10. Demonstration of polarization mode selection and coupling efficiency of optofluidic ring resonator lasers.

    PubMed

    Zhang, Yuanxian; Meng, Weidong; Yang, Hongyue; Chu, Yufei; Pu, Xiaoyun

    2015-11-01

    We demonstrate the polarization mode selection and the dependence of coupling efficiency on polarization state of pump light for an optofluidic ring resonator (OFRR) laser. An optical fiber is chosen to serve as the ring resonator and surrounded by rhodamine 6G dye solution of lower refractive index as the fluidic gain medium. When the ring resonator is pumped by a linearly s-polarized laser, the emitted whispering gallery mode (WGM) lasing is of parallel polarization (TM mode), while p-polarized laser excitation generates a vertically polarized lasing emission (TE mode), both TM and TE mode lasing emission coexist simultaneously if the ring resonator is pumped by the s- and p-mixed polarized light. Further investigation reveals that the lasing intensity of the TM mode is approximately twice that of the TE mode for the same pump energy density, meaning an obvious difference of coupling efficiency on the polarization state of pump light; the experimental results of coupling efficiency are well explained by an induced dipole model. PMID:26512529

  11. Using speech for mode selection in control of multifunctional myoelectric prostheses.

    PubMed

    Fang, Peng; Wei, Zheng; Geng, Yanjuan; Yao, Fuan; Li, Guanglin

    2013-01-01

    Electromyogram (EMG) recorded from residual muscles of limbs is considered as suitable control information for motorized prostheses. However, in case of high-level amputations, the residual muscles are usually limited, which may not provide enough EMG for flexible control of myoelectric prostheses with multiple degrees of freedom of movements. Here, we proposed a control strategy, where the speech signals were used as additional information and combined with the EMG signals to realize more flexible control of multifunctional prostheses. By replacing the traditional "sequential mode-switching (joint-switching)", the speech signals were used to select a mode (joint) of the prosthetic arm, and then the EMG signals were applied to determine a motion class involved in the selected joint and to execute the motion. Preliminary results from three able-bodied subjects and one transhumeral amputee demonstrated the proposed strategy could achieve a high mode-selection rate and enhance the operation efficiency, suggesting the strategy may improve the control performance of commercial myoelectric prostheses. PMID:24110509

  12. Design and optimization of a multi-element piezoelectric transducer for mode-selective generation of guided waves

    NASA Astrophysics Data System (ADS)

    Yazdanpanah Moghadam, Peyman; Quaegebeur, Nicolas; Masson, Patrice

    2016-07-01

    A novel multi-element piezoelectric transducers (MEPT) is designed, optimized, machined and experimentally tested to improve structural health monitoring systems for mode-selective generation of guided waves (GW) in an isotropic structure. GW generation using typical piezoceramics makes the signal processing and consequently damage detection very complicated because at any driving frequency at least two fundamental symmetric (S 0) and antisymmetric (A 0) modes are generated. To prevent this, mode selective transducer design is proposed based on MEPT. A numerical method is first developed to extract the interfacial stress between a single piezoceramic element and a host structure and then used as the input of an analytical model to predict the GW propagation through the thickness of an isotropic plate. Two novel objective functions are proposed to optimize the interfacial shear stress for both suppressing unwanted mode(s) and maximizing the desired mode. Simplicity and low manufacturing cost are two main targets driving the design of the MEPT. A prototype MEPT is then manufactured using laser micro-machining. An experimental procedure is presented to validate the performances of the MEPT as a new solution for mode-selective GW generation. Experimental tests illustrate the high capability of the MEPT for mode-selective GW generation, as unwanted mode is suppressed by a factor up to 170 times compared with the results obtained with a single piezoceramic.

  13. ADDER CIRCUIT

    DOEpatents

    Jacobsohn, D.H.; Merrill, L.C.

    1959-01-20

    An improved parallel addition unit is described which is especially adapted for use in electronic digital computers and characterized by propagation of the carry signal through each of a plurality of denominationally ordered stages within a minimum time interval. In its broadest aspects, the invention incorporates a fast multistage parallel digital adder including a plurality of adder circuits, carry-propagation circuit means in all but the most significant digit stage, means for conditioning each carry-propagation circuit during the time period in which information is placed into the adder circuits, and means coupling carry-generation portions of thc adder circuit to the carry propagating means.

  14. Mode-selection and mode-switching of an autonomous motor composed of a camphor rotor and a mobile loop

    NASA Astrophysics Data System (ADS)

    Nakata, Satoshi; Tenno, Ryoichi; Ikura, Yumihiko S.

    2011-09-01

    Mode-selection and mode-switching of self-motion were investigated for a loop driven by the movement of a camphor rotor on water, as a simple autonomous system. Three modes of self-motion (caterpillar motion, translation, and alternating mode-switching between them) were selectively generated depending on the state of a knot of the loop. The experimental results were numerically reproduced and categorized by using a differential equation of rotation with a fold bifurcation.

  15. MULTIPLIER CIRCUIT

    DOEpatents

    Thomas, R.E.

    1959-01-20

    An electronic circuit is presented for automatically computing the product of two selected variables by multiplying the voltage pulses proportional to the variables. The multiplier circuit has a plurality of parallel resistors of predetermined values connected through separate gate circults between a first input and the output terminal. One voltage pulse is applied to thc flrst input while the second voltage pulse is applied to control circuitry for the respective gate circuits. Thc magnitude of the second voltage pulse selects the resistors upon which the first voltage pulse is imprcssed, whereby the resultant output voltage is proportional to the product of the input voltage pulses

  16. GATING CIRCUITS

    DOEpatents

    Merrill, L.C.

    1958-10-14

    Control circuits for vacuum tubes are described, and a binary counter having an improved trigger circuit is reported. The salient feature of the binary counter is the application of the input signal to the cathode of each of two vacuum tubes through separate capacitors and the connection of each cathode to ground through separate diodes. The control of the binary counter is achieved in this manner without special pulse shaping of the input signal. A further advantage of the circuit is the simplicity and minimum nuruber of components required, making its use particularly desirable in computer machines.

  17. TRIPPING CIRCUIT

    DOEpatents

    Lees, G.W.; McCormick, E.D.

    1962-05-22

    A tripping circuit employing a magnetic amplifier for tripping a reactor in response to power level, period, or instrument failure is described. A reference winding and signal winding are wound in opposite directions on the core. Current from an ion chamber passes through both windings. If the current increases at too fast a rate, a shunt circuit bypasses one or the windings and the amplifier output reverses polarity. (AEC)

  18. MULTIPLIER CIRCUIT

    DOEpatents

    Chase, R.L.

    1963-05-01

    An electronic fast multiplier circuit utilizing a transistor controlled voltage divider network is presented. The multiplier includes a stepped potentiometer in which solid state or transistor switches are substituted for mechanical wipers in order to obtain electronic switching that is extremely fast as compared to the usual servo-driven mechanical wipers. While this multiplier circuit operates as an approximation and in steps to obtain a voltage that is the product of two input voltages, any desired degree of accuracy can be obtained with the proper number of increments and adjustment of parameters. (AEC)

  19. Circuit Training.

    ERIC Educational Resources Information Center

    Nelson, Jane B.

    1998-01-01

    Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

  20. Mode- and wavelength-division multiplexed transmission using all-fiber mode multiplexer based on mode selective couplers.

    PubMed

    Chang, Sun Hyok; Chung, Hwan Seok; Ryf, Roland; Fontaine, Nicolas K; Han, Changyo; Park, Kyung Jun; Kim, Kwangjoon; Lee, Jyung Chan; Lee, Jong Hyun; Kim, Byoung Yoon; Kim, Young Kie

    2015-03-23

    We propose all-fiber mode multiplexer composed of two consecutive LP₁₁ mode selective couplers that allows for the multiplexing of LP₀₁ mode and two-fold degenerate LP₁₁ modes. We demonstrate WDM transmission of 32 wavelength channels with 100 GHz spacing, each carrying 3 modes of 120 Gb/s polarization division multiplexed quadrature phase shifted keying (PDM-QPSK) signal, over 560 km of few-mode fiber (FMF). Long distance transmission is achieved by 6×6 multiple-input multiple-output digital signal processing and modal differential group delay compensated link of FMF. The all-fiber mode multiplexer has considerable potential to be used in mode- and wavelength-division multiplexed transmission. PMID:25837061

  1. Mode-selective amplification in a large mode area Yb-doped fiber using a photonic lantern.

    PubMed

    Wittek, S; Bustos Ramirez, R; Alvarado Zacarias, J; Sanjabi Eznaveh, Z; Bradford, J; Lopez Galmiche, G; Zhang, D; Zhu, W; Antonio-Lopez, J; Shah, L; Amezcua Correa, R

    2016-05-15

    We demonstrate selective spatial mode amplification in a few mode, double-clad Yb-doped large mode area (LMA) fiber, utilizing an all-fiber photonic lantern. Amplification to multi-watt output power is achieved while preserving high spatial mode selectivity. We observe gain values of over 12 dB for all modes: LP01, LP11a, and LP11b, when amplified individually. Additionally, we investigate the simultaneous amplification of LP01+LP11a and LP11a+LP11b, and the resultant mode competition. The proposed architecture allows for the reconfigurable excitation of spatial modes in the LMA fiber amplifiers, and represents a promising method that could enable dynamic spatial mode control in high power fiber lasers. PMID:27176951

  2. DIELECTRIC-LOADED WAVE-GUIDES

    DOEpatents

    Robertson-Shersby-Harvie, R.B.; Mullett, L.B.

    1957-04-23

    This patent presents a particular arrangement for delectric loading of a wave-guide carrying an electromagnetic wave in the E or TM mode of at least the second order, to reduce the power dissipated as the result of conduction loss in the wave-guide walls. To achieve this desirabie result, the effective dielectric constants in the radial direction of adjacent coaxial tubular regions bounded approximateiy by successive nodai surfaces within the electromagnetic field are of two different values alternating in the radial direction, the intermost and outermost regions being of the lower value, and the dielectric constants between nodes are uniform.

  3. Circuit Connectors

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The U-shaped wire devices in the upper photo are Digi-Klipsm; aids to compact packaging of electrical and electronic devices. They serve as connectors linking the circuitry of one circuit board with another in multi-board systems. Digi-Klips were originally developed for Goddard Space Flight Center to meet a need for lightweight, reliable connectors to replace hand-wired connections formerly used in spacecraft. They are made of beryllium copper wire, noted for its excellent conductivity and its spring-like properties, which assure solid electrical contact over a long period of time.

  4. Experimental demonstration of mode-selective phonon excitation of 6H-SiC by a mid-infrared laser with anti-Stokes Raman scattering spectroscopy

    SciTech Connect

    Yoshida, Kyohei; Hachiya, Kan; Okumura, Kensuke; Mishima, Kenta; Inukai, Motoharu; Torgasin, Konstantin; Omer, Mohamed; Sonobe, Taro; Zen, Heishun; Negm, Hani; Kii, Toshiteru; Masuda, Kai; Ohgaki, Hideaki

    2013-10-28

    Mode-selective phonon excitation by a mid-infrared laser (MIR-FEL) is demonstrated via anti-Stokes Raman scattering measurements of 6H-silicon carbide (SiC). Irradiation of SiC with MIR-FEL and a Nd-YAG laser at 14 K produced a peak where the Raman shift corresponds to a photon energy of 119 meV (10.4 μm). This phenomenon is induced by mode-selective phonon excitation through the irradiation of MIR-FEL, whose photon energy corresponds to the photon-absorption of a particular phonon mode.

  5. LOGIC CIRCUIT

    DOEpatents

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  6. Continuous sensors for mode selective actuation and reception of waves for structural health monitoring of woven composite laminates

    NASA Astrophysics Data System (ADS)

    Kirikera, Goutham R.; Petculescu, Gabriela; Krishnaswamy, Sridhar; Achenbach, Jan D.

    2007-04-01

    The quantitative evaluation of damage in woven composites using mode selective excitation of Lamb waves is reported in this paper. PVDF (polyvinylidene fluoride) comb sensors are used to generate and detect a single plate mode. The top electrode is a single set of equidistant fingers connected in parallel to the same potential while the bottom electrode is kept at ground. First, a pair of such sensors is used to generate and detect a single plate mode. Group velocity changes of a wave packet traveling through the damaged area are used for quantitative damage estimation. Second, a new electrode configuration is used in order to improve the receiver signal. The proposed configuration referred to as continuous sensors, is used in structural health monitoring (SHM) for detection of growing cracks. Theoretical and experimental results are presented. In addition, an analog circuitry to actuate the structure at high frequency (~1MHz) based on energy tapped from a vibrating cantilever beam (~20Hz) is developed, towards a high-frequency energy-harvested SHM.

  7. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  8. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, W.J.

    1981-11-10

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components. 13 figs.

  9. Mode Selection Rules for Two-Delay Systems: Dynamical Explanation for the Function of the Register Hole on the Clarinet

    NASA Astrophysics Data System (ADS)

    Takahashi, Kin'ya; Goya, Kana; Goya, Saya

    2014-12-01

    Generally, time-delay systems are regarded as multi-attractor systems. We investigate mode selection rules for two-delay systems considering which oscillation mode is first excited by the Hopf bifurcation with increasing a bifurcation parameter. In particular, we focus on the case that the strength of the short time delay α1 is lower than that of the long time delay α2. In a certain range of α1/α2 in which it is sufficiently small but still not negligible, the third-harmonic mode occupies a particular range of the ratio of the two delay times such that 2 < tR2/tR1 < 4, where tR1 and tR2 denote the short and long delay times, respectively. This is the key for understanding the function of the register hole on the clarinet, which is smaller in radius than the other tone holes, but works well to raise the pitch of first register notes in a wide range more than an octave by a twelfth (19 semitones), i.e., generating third harmonics, when opened. This is confirmed using a simple model of the clarinet with two delays: short and long time delays are regarded as delayed reflections caused by the register hole and the open end of the pipe, respectively. The working range of the register hole roughly corresponds to the particular range of the third-harmonic mode for two-delay systems (2 < tR2/tR1 < 4).

  10. A simple tachometer circuit

    NASA Technical Reports Server (NTRS)

    Dimeff, J.

    1972-01-01

    Electric circuit to measure frequency of repetitive sinusoidal or rectangular wave is presented. Components of electric circuit and method of operation are explained. Application of circuit as tachometer for automobile is discussed.

  11. Photomultiplier blanking circuit

    NASA Technical Reports Server (NTRS)

    Mcclenahan, J. O.

    1972-01-01

    Circuit for protecting photomultiplier equipment from current surges which occur when exposed to brilliant illumination is discussed. Components of circuit and details of operation are provided. Circuit diagram to show action of blanking pulse on zener diode is included.

  12. Charge regulation circuit

    DOEpatents

    Ball, Don G.

    1992-01-01

    A charge regulation circuit provides regulation of an unregulated voltage supply in the range of 0.01%. The charge regulation circuit is utilized in a preferred embodiment in providing regulated voltage for controlling the operation of a laser.

  13. Linear integrated circuits

    NASA Astrophysics Data System (ADS)

    Young, T.

    This book is intended to be used as a textbook in a one-semester course at a variety of levels. Because of self-study features incorporated, it may also be used by practicing electronic engineers as a formal and thorough introduction to the subject. The distinction between linear and digital integrated circuits is discussed, taking into account digital and linear signal characteristics, linear and digital integrated circuit characteristics, the definitions for linear and digital circuits, applications of digital and linear integrated circuits, aspects of fabrication, packaging, and classification and numbering. Operational amplifiers are considered along with linear integrated circuit (LIC) power requirements and power supplies, voltage and current regulators, linear amplifiers, linear integrated circuit oscillators, wave-shaping circuits, active filters, DA and AD converters, demodulators, comparators, instrument amplifiers, current difference amplifiers, analog circuits and devices, and aspects of troubleshooting.

  14. Electrical Circuits and Water Analogies

    ERIC Educational Resources Information Center

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  15. Sense circuit arrangement

    NASA Technical Reports Server (NTRS)

    Bohning, Oliver D. (Inventor)

    1976-01-01

    A unique, two-node sense circuit is disclosed. The circuit includes a bridge comprised of resistance elements and a differential amplifier. The two-node circuit is suitably adapted to be arranged in an array comprised of a plurality of discrete bridge-amplifiers which can be selectively energized. The circuit is arranged so as to form a configuration with minimum power utilization and a reduced number of components and interconnections therebetween.

  16. Electrical Circuit Simulation Code

    Energy Science and Technology Software Center (ESTSC)

    2001-08-09

    Massively-Parallel Electrical Circuit Simulation Code. CHILESPICE is a massively-arallel distributed-memory electrical circuit simulation tool that contains many enhanced radiation, time-based, and thermal features and models. Large scale electronic circuit simulation. Shared memory, parallel processing, enhance convergence. Sandia specific device models.

  17. Piezoelectric drive circuit

    DOEpatents

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  18. Piezoelectric drive circuit

    DOEpatents

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  19. CIRCUITS FOR CURRENT MEASUREMENTS

    DOEpatents

    Cox, R.J.

    1958-11-01

    Circuits are presented for measurement of a logarithmic scale of current flowing in a high impedance. In one form of the invention the disclosed circuit is in combination with an ionization chamber to measure lonization current. The particular circuit arrangement lncludes a vacuum tube having at least one grid, an ionization chamber connected in series with a high voltage source and the grid of the vacuum tube, and a d-c amplifier feedback circuit. As the ionization chamber current passes between the grid and cathode of the tube, the feedback circuit acts to stabilize the anode current, and the feedback voltage is a measure of the logaritbm of the ionization current.

  20. Source circuit design considerations

    NASA Astrophysics Data System (ADS)

    Noel, G. T.

    1983-11-01

    The cost of several circuit configurations for large (5MW) array fields were investigated to assess the relative costs of high and low voltage configurations. Three source circuit NOC voltages were evaluated: 400V (ungrounded), 800V (+ or 400V center grounded), and 2000V (+ or - 1000V center grounded). Four source circuit configurations were considered for each of the three NOC voltages. The configurations correspond to source circuit currents of 15, 30, 45, and 60 amperes, respectively. Conceptual layouts for 5MW building blocks for each of the above configurations were developed. The designs were optimized to minimize BOS electrical and structural costs. Only the BOS electrical costs were evaluated. The designs were broken down into the following elements for cost: (1) basic source circuit intermodule wiring, bypass diodes and associated hardware, source circuit to J-Box wiring, etc; (2) J-Box blocking diodes, varistors, heat sinks, and housing; (3) disconnects source circuit disconnects, fuses, and housing; (4) bus cabling J-Box to PCU interface wiring, and trenching; (5) interface bus bar, group disconnects, and fuses; and (6) fault detection shunts, signal wire, electronics, and alarm. It is concluded that high voltage low current circuits are not economical, at higher currents high and low voltage circuit costs approach each other, high voltage circuits are not likely to offer near term advantage, and development work/manufacturer stimulation is needed to develop low cost high voltage hardware.

  1. Source circuit design considerations

    NASA Technical Reports Server (NTRS)

    Noel, G. T.

    1983-01-01

    The cost of several circuit configurations for large (5MW) array fields were investigated to assess the relative costs of high and low voltage configurations. Three source circuit NOC voltages were evaluated: 400V (ungrounded), 800V (+ or 400V center grounded), and 2000V (+ or - 1000V center grounded). Four source circuit configurations were considered for each of the three NOC voltages. The configurations correspond to source circuit currents of 15, 30, 45, and 60 amperes, respectively. Conceptual layouts for 5MW building blocks for each of the above configurations were developed. The designs were optimized to minimize BOS electrical and structural costs. Only the BOS electrical costs were evaluated. The designs were broken down into the following elements for cost: (1) basic source circuit intermodule wiring, bypass diodes and associated hardware, source circuit to J-Box wiring, etc; (2) J-Box blocking diodes, varistors, heat sinks, and housing; (3) disconnects source circuit disconnects, fuses, and housing; (4) bus cabling J-Box to PCU interface wiring, and trenching; (5) interface bus bar, group disconnects, and fuses; and (6) fault detection shunts, signal wire, electronics, and alarm. It is concluded that high voltage low current circuits are not economical, at higher currents high and low voltage circuit costs approach each other, high voltage circuits are not likely to offer near term advantage, and development work/manufacturer stimulation is needed to develop low cost high voltage hardware.

  2. [Shunt and short circuit].

    PubMed

    Rangel-Abundis, Alberto

    2006-01-01

    Shunt and short circuit are antonyms. In French, the term shunt has been adopted to denote the alternative pathway of blood flow. However, in French, as well as in Spanish, the word short circuit (court-circuit and cortocircuito) is synonymous with shunt, giving rise to a linguistic and scientific inconsistency. Scientific because shunt and short circuit made reference to a phenomenon that occurs in the field of the physics. Because shunt and short circuit are antonyms, it is necessary to clarify that shunt is an alternative pathway of flow from a net of high resistance to a net of low resistance, maintaining the stream. Short circuit is the interruption of the flow, because a high resistance impeaches the flood. This concept is applied to electrical and cardiovascular physiology, as well as to the metabolic pathways. PMID:17257492

  3. Automatic circuit interrupter

    NASA Technical Reports Server (NTRS)

    Dwinell, W. S.

    1979-01-01

    In technique, voice circuits connecting crew's cabin to launch station through umbilical connector disconnect automatically unused, or deadened portion of circuits immediately after vehicle is launched, eliminating possibility that unused wiring interferes with voice communications inside vehicle or need for manual cutoff switch and its associated wiring. Technique is applied to other types of electrical actuation circuits, also launch of mapped vehicles, such as balloons, submarines, test sleds, and test chambers-all requiring assistance of ground crew.

  4. Regenerative feedback resonant circuit

    DOEpatents

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  5. Remote reset circuit

    DOEpatents

    Gritzo, R.E.

    1985-09-12

    A remote reset circuit acts as a stand-along monitor and controller by clocking in each character sent by a terminal to a computer and comparing it to a given reference character. When a match occurs, the remote reset circuit activates the system's hardware reset line. The remote reset circuit is hardware based centered around monostable multivibrators and is unaffected by system crashes, partial serial transmissions, or power supply transients. 4 figs.

  6. Remote reset circuit

    DOEpatents

    Gritzo, Russell E.

    1987-01-01

    A remote reset circuit acts as a stand-alone monitor and controller by clocking in each character sent by a terminal to a computer and comparing it to a given reference character. When a match occurs, the remote reset circuit activates the system's hardware reset line. The remote reset circuit is hardware based centered around monostable multivibrators and is unaffected by system crashes, partial serial transmissions, or power supply transients.

  7. Printed circuit board industry.

    PubMed

    LaDou, Joseph

    2006-05-01

    The printed circuit board is the platform upon which microelectronic components such as semiconductor chips and capacitors are mounted. It provides the electrical interconnections between components and is found in virtually all electronics products. Once considered low technology, the printed circuit board is evolving into a high-technology product. Printed circuit board manufacturing is highly complicated, requiring large equipment investments and over 50 process steps. Many of the high-speed, miniaturized printed circuit boards are now manufactured in cleanrooms with the same health and safety problems posed by other microelectronics manufacturing. Asia produces three-fourths of the world's printed circuit boards. In Asian countries, glycol ethers are the major solvents used in the printed circuit board industry. Large quantities of hazardous chemicals such as formaldehyde, dimethylformamide, and lead are used by the printed circuit board industry. For decades, chemically intensive and often sloppy manufacturing processes exposed tens of thousands of workers to a large number of chemicals that are now known to be reproductive toxicants and carcinogens. The printed circuit board industry has exposed workers to high doses of toxic metals, solvents, acids, and photolithographic chemicals. Only recently has there been any serious effort to diminish the quantity of lead distributed worldwide by the printed circuit board industry. Billions of electronics products have been discarded in every region of the world. This paper summarizes recent regulatory and enforcement efforts. PMID:16580876

  8. Understanding Simple Circuits

    ERIC Educational Resources Information Center

    Mant, Jenny; Wilson, Helen

    2007-01-01

    Many envisage electricity as the "power" to "do things." They know that electricity needs "circuits" and that something is "flowing" in the circuits, but they are not sure what or why. Words such as "current" and "voltage" are part of electricity but their meaning, and the difference between them, is not always clear. In this article, the authors…

  9. Liquid detection circuit

    DOEpatents

    Regan, Thomas O.

    1987-01-01

    Herein is a circuit which is capable of detecting the presence of liquids, especially cryogenic liquids, and whose sensor will not overheat in a vacuum. The circuit parameters, however, can be adjusted to work with any liquid over a wide range of temperatures.

  10. Computer circuit card puller

    NASA Technical Reports Server (NTRS)

    Sawyer, R. V.; Szuwalski, B. (Inventor)

    1981-01-01

    The invention generally relates to hand tools, and more particularly to an improved device for facilitating removal of printed circuit cards from a card rack characterized by longitudinal side rails arranged in a mutually spaced parallelism and a plurality of printed circuit cards extended between the rails of the rack.

  11. A Virtual Circuits Lab

    ERIC Educational Resources Information Center

    Vick, Matthew E.

    2010-01-01

    The University of Colorado's Physics Education Technology (PhET) website offers free, high-quality simulations of many physics experiments that can be used in the classroom. The Circuit Construction Kit, for example, allows students to safely and constructively play with circuit components while learning the mathematics behind many circuit…

  12. Genetic circuit design automation.

    PubMed

    Nielsen, Alec A K; Der, Bryan S; Shin, Jonghyeon; Vaidyanathan, Prashant; Paralanov, Vanya; Strychalski, Elizabeth A; Ross, David; Densmore, Douglas; Voigt, Christopher A

    2016-04-01

    Computation can be performed in living cells by DNA-encoded circuits that process sensory information and control biological functions. Their construction is time-intensive, requiring manual part assembly and balancing of regulator expression. We describe a design environment, Cello, in which a user writes Verilog code that is automatically transformed into a DNA sequence. Algorithms build a circuit diagram, assign and connect gates, and simulate performance. Reliable circuit design requires the insulation of gates from genetic context, so that they function identically when used in different circuits. We used Cello to design 60 circuits forEscherichia coli(880,000 base pairs of DNA), for which each DNA sequence was built as predicted by the software with no additional tuning. Of these, 45 circuits performed correctly in every output state (up to 10 regulators and 55 parts), and across all circuits 92% of the output states functioned as predicted. Design automation simplifies the incorporation of genetic circuits into biotechnology projects that require decision-making, control, sensing, or spatial organization. PMID:27034378

  13. Amplifier improvement circuit

    NASA Technical Reports Server (NTRS)

    Sturman, J.

    1968-01-01

    Stable input stage was designed for the use with a integrated circuit operational amplifier to provide improved performance as an instrumentation-type amplifier. The circuit provides high input impedance, stable gain, good common mode rejection, very low drift, and low output impedance.

  14. Parasitic suppressing circuit

    NASA Technical Reports Server (NTRS)

    Fowler, J. T.; Raposa, F. L. (Inventor)

    1973-01-01

    A circuit for suppressing parasitic oscillations across an inductor operating in a resonant mode is described. The circuit includes a switch means and resistive means connected serially across the inductor. A unidirectional resistive-capacitive network is also connected across the inductor and to the switch means to automatically render the switch means conducting when inductive current through the inductor ceases to flow.

  15. Completing a Simple Circuit.

    ERIC Educational Resources Information Center

    Slater, Timothy F.; Adams, Jeffrey P.; Brown, Thomas R.

    2000-01-01

    Students have problems successfully arranging an electric circuit to make the bulb produce light. Investigates the percentage of students able to complete a circuit with a given apparatus, and the effects of prior experience on student success. Recommends hands-on activities at the elementary and secondary school levels. (Contains 14 references.)…

  16. Thermocouple-Signal-Conditioning Circuit

    NASA Technical Reports Server (NTRS)

    Simon, Richard A.

    1991-01-01

    Thermocouple-signal-conditioning circuit acting in conjunction with thermocouple, exhibits electrical behavior of voltage in series with resistance. Combination part of input bridge circuit of controller. Circuit configured for either of two specific applications by selection of alternative resistances and supply voltages. Includes alarm circuit detecting open circuit in thermocouple and provides off-scale output to signal malfunctions.

  17. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, David M.

    1996-01-01

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit.

  18. Compensated gain control circuit for buck regulator command charge circuit

    DOEpatents

    Barrett, D.M.

    1996-11-05

    A buck regulator command charge circuit includes a compensated-gain control signal for compensating for changes in the component values in order to achieve optimal voltage regulation. The compensated-gain control circuit includes an automatic-gain control circuit for generating a variable-gain control signal. The automatic-gain control circuit is formed of a precision rectifier circuit, a filter network, an error amplifier, and an integrator circuit. 5 figs.

  19. Sensor readout detector circuit

    DOEpatents

    Chu, D.D.; Thelen, D.C. Jr.

    1998-08-11

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems. 6 figs.

  20. Sensor readout detector circuit

    DOEpatents

    Chu, Dahlon D.; Thelen, Jr., Donald C.

    1998-01-01

    A sensor readout detector circuit is disclosed that is capable of detecting sensor signals down to a few nanoamperes or less in a high (microampere) background noise level. The circuit operates at a very low standby power level and is triggerable by a sensor event signal that is above a predetermined threshold level. A plurality of sensor readout detector circuits can be formed on a substrate as an integrated circuit (IC). These circuits can operate to process data from an array of sensors in parallel, with only data from active sensors being processed for digitization and analysis. This allows the IC to operate at a low power level with a high data throughput for the active sensors. The circuit may be used with many different types of sensors, including photodetectors, capacitance sensors, chemically-sensitive sensors or combinations thereof to provide a capability for recording transient events or for recording data for a predetermined period of time following an event trigger. The sensor readout detector circuit has applications for portable or satellite-based sensor systems.

  1. Polymorphic Electronic Circuits

    NASA Technical Reports Server (NTRS)

    Stoica, Adrian

    2004-01-01

    Polymorphic electronics is a nascent technological discipline that involves, among other things, designing the same circuit to perform different analog and/or digital functions under different conditions. For example, a circuit can be designed to function as an OR gate or an AND gate, depending on the temperature (see figure). Polymorphic electronics can also be considered a subset of polytronics, which is a broader technological discipline in which optical and possibly other information- processing systems could also be designed to perform multiple functions. Polytronics is an outgrowth of evolvable hardware (EHW). The basic concepts and some specific implementations of EHW were described in a number of previous NASA Tech Briefs articles. To recapitulate: The essence of EHW is to design, construct, and test a sequence of populations of circuits that function as incrementally better solutions of a given design problem through the selective, repetitive connection and/or disconnection of capacitors, transistors, amplifiers, inverters, and/or other circuit building blocks. The evolution is guided by a search-and-optimization algorithm (in particular, a genetic algorithm) that operates in the space of possible circuits to find a circuit that exhibits an acceptably close approximation of the desired functionality. The evolved circuits can be tested by computational simulation (in which case the evolution is said to be extrinsic), tested in real hardware (in which case the evolution is said to be intrinsic), or tested in random sequences of computational simulation and real hardware (in which case the evolution is said to be mixtrinsic).

  2. Approximate circuits for increased reliability

    SciTech Connect

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  3. Approximate circuits for increased reliability

    SciTech Connect

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  4. Gallium Arsenide Domino Circuit

    NASA Technical Reports Server (NTRS)

    Yang, Long; Long, Stephen I.

    1990-01-01

    Advantages include reduced power and high speed. Experimental gallium arsenide field-effect-transistor (FET) domino circuit replicated in large numbers for use in dynamic-logic systems. Name of circuit denotes mode of operation, which logic signals propagate from each stage to next when successive stages operated at slightly staggered clock cycles, in manner reminiscent of dominoes falling in a row. Building block of domino circuit includes input, inverter, and level-shifting substages. Combinational logic executed in input substage. During low half of clock cycle, result of logic operation transmitted to following stage.

  5. DIFFERENTIAL FAULT SENSING CIRCUIT

    DOEpatents

    Roberts, J.H.

    1961-09-01

    A differential fault sensing circuit is designed for detecting arcing in high-voltage vacuum tubes arranged in parallel. A circuit is provided which senses differences in voltages appearing between corresponding elements likely to fault. Sensitivity of the circuit is adjusted to some level above which arcing will cause detectable differences in voltage. For particular corresponding elements, a group of pulse transformers are connected in parallel with diodes connected across the secondaries thereof so that only voltage excursions are transmitted to a thyratron which is biased to the sensitivity level mentioned.

  6. Power supply conditioning circuit

    NASA Technical Reports Server (NTRS)

    Primas, Lori E. (Inventor); Loveland, Rohan C. (Inventor)

    1988-01-01

    A conditioning circuit is provided with a constant current diode in series with a zener diode, the former having a high dynamic impedance and the latter a low dynamic impedance. The constant current diode can receive an input voltage with PARD. In conjunction with the zener diode fixed to a ground, a voltage divider is provided which can give an output voltage whose PARD was significantly reduced. The conditioning circuit is effective down to dc.

  7. Circuit simulation: some humbling thoughts

    SciTech Connect

    Wendt, Manfred; /Fermilab

    2006-01-01

    A short, very personal note on circuit simulation is presented. It does neither include theoretical background on circuit simulation, nor offers an overview of available software, but just gives some general remarks for a discussion on circuit simulator needs in context to the design and development of accelerator beam instrumentation circuits and systems.

  8. Superconducting flux flow digital circuits

    DOEpatents

    Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

    1995-02-14

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

  9. Superconducting flux flow digital circuits

    DOEpatents

    Hietala, Vincent M.; Martens, Jon S.; Zipperian, Thomas E.

    1995-01-01

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

  10. ELECTRONIC MULTIPLIER CIRCUIT

    DOEpatents

    Thomas, R.E.

    1959-08-25

    An electronic multiplier circuit is described in which an output voltage having an amplitude proportional to the product or quotient of the input signals is accomplished in a novel manner which facilitates simplicity of circuit construction and a high degree of accuracy in accomplishing the multiplying and dividing function. The circuit broadly comprises a multiplier tube in which the plate current is proportional to the voltage applied to a first control grid multiplied by the difference between voltage applied to a second control grid and the voltage applied to the first control grid. Means are provided to apply a first signal to be multiplied to the first control grid together with means for applying the sum of the first signal to be multiplied and a second signal to be multiplied to the second control grid whereby the plate current of the multiplier tube is proportional to the product of the first and second signals to be multiplied.

  11. ELECTRONIC TRIGGER CIRCUIT

    DOEpatents

    Russell, J.A.G.

    1958-01-01

    An electronic trigger circuit is described of the type where an output pulse is obtained only after an input voltage has cqualed or exceeded a selected reference voltage. In general, the invention comprises a source of direct current reference voltage in series with an impedance and a diode rectifying element. An input pulse of preselected amplitude causes the diode to conduct and develop a signal across the impedance. The signal is delivered to an amplifier where an output pulse is produced and part of the output is fed back in a positive manner to the diode so that the amplifier produces a steep wave front trigger pulsc at the output. The trigger point of the described circuit is not subject to variation due to the aging, etc., of multi-electrode tabes, since the diode circuit essentially determines the trigger point.

  12. Logsum Using Garbled Circuits

    PubMed Central

    Portêlo, José; Raj, Bhiksha; Trancoso, Isabel

    2015-01-01

    Secure multiparty computation allows for a set of users to evaluate a particular function over their inputs without revealing the information they possess to each other. Theoretically, this can be achieved using fully homomorphic encryption systems, but so far they remain in the realm of computational impracticability. An alternative is to consider secure function evaluation using homomorphic public-key cryptosystems or Garbled Circuits, the latter being a popular trend in recent times due to important breakthroughs. We propose a technique for computing the logsum operation using Garbled Circuits. This technique relies on replacing the logsum operation with an equivalent piecewise linear approximation, taking advantage of recent advances in efficient methods for both designing and implementing Garbled Circuits. We elaborate on how all the required blocks should be assembled in order to obtain small errors regarding the original logsum operation and very fast execution times. PMID:25811740

  13. ELECTRONIC PHASE CONTROL CIRCUIT

    DOEpatents

    Salisbury, J.D.; Klein, W.W.; Hansen, C.F.

    1959-04-21

    An electronic circuit is described for controlling the phase of radio frequency energy applied to a multicavity linear accelerator. In one application of the circuit two cavities are excited from a single radio frequency source, with one cavity directly coupled to the source and the other cavity coupled through a delay line of special construction. A phase detector provides a bipolar d-c output signal proportional to the difference in phase between the voltage in the two cavities. This d-c signal controls a bias supply which provides a d-c output for varying the capacitnce of voltage sensitive capacitors in the delay line. The over-all operation of the circuit is completely electronic, overcoming the time response limitations of the electromechanical control systems, and the relative phase relationship of the radio frequency voltages in the two caviiies is continuously controlled to effect particle acceleration.

  14. Picosecond Imaging Circuit Analysis

    NASA Astrophysics Data System (ADS)

    Kash, Jeffrey A.

    1998-03-01

    With ever-increasing complexity, probing the internal operation of a silicon IC becomes more challenging. Present methods of internal probing are becoming obsolete. We have discovered that a very weak picosecond pulse of light is emitted by each FET in a CMOS circuit whenever the circuit changes logic state. This pulsed emission can be simultaneously imaged and time resolved, using a technique we have named Picosecond Imaging Circuit Analysis (PICA). With a suitable imaging detector, PICA allows time resolved measurement on thousands of devices simultaneously. Computer videos made from measurements on real IC's will be shown. These videos, along with a more quantitative evaluation of the light emission, permit the complete operation of an IC to be measured in a non-invasive way with picosecond time resolution.

  15. Inrush Current Control Circuit

    NASA Technical Reports Server (NTRS)

    Cole, Steven W. (Inventor)

    2002-01-01

    An inrush current control circuit having an input terminal connected to a DC power supply and an output terminal connected to a load capacitor limits the inrush current that charges up the load capacitor during power up of a system. When the DC power supply applies a DC voltage to the input terminal, the inrush current control circuit produces a voltage ramp at the load capacitor instead of an abrupt DC voltage. The voltage ramp results in a constant low level current to charge up the load capacitor, greatly reducing the current drain on the DC power supply.

  16. Electrical Circuit Tester

    DOEpatents

    Love, Frank

    2006-04-18

    An electrical circuit testing device is provided, comprising a case, a digital voltage level testing circuit with a display means, a switch to initiate measurement using the device, a non-shorting switching means for selecting pre-determined electrical wiring configurations to be tested in an outlet, a terminal block, a five-pole electrical plug mounted on the case surface and a set of adapters that can be used for various multiple-pronged electrical outlet configurations for voltages from 100 600 VAC from 50 100 Hz.

  17. Small circuits for cryptography.

    SciTech Connect

    Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree; Miller, Russell D.; Anderson, William Erik

    2005-10-01

    This report examines a number of hardware circuit design issues associated with implementing certain functions in FPGA and ASIC technologies. Here we show circuit designs for AES and SHA-1 that have an extremely small hardware footprint, yet show reasonably good performance characteristics as compared to the state of the art designs found in the literature. Our AES performance numbers are fueled by an optimized composite field S-box design for the Stratix chipset. Our SHA-1 designs use register packing and feedback functionalities of the Stratix LE, which reduce the logic element usage by as much as 72% as compared to other SHA-1 designs.

  18. Micromachined Silicon Waveguide Circuits

    NASA Technical Reports Server (NTRS)

    McGrath, W. R.

    1995-01-01

    Rectangular waveguides are commonly used as circuit elements in remote-sensing heterodyne receivers at millimeter wavelengths. The advantages of waveguides are low loss and mechanical tunability. However, conventional machining techniques for waveguide components operating above a few hundred GHz are complicated and costly. Waveguides micromachined from silicon however would have several important advantages including low-cost; small size for very high frequency (submillimeter wave) operation; high dimensional accuracy (important for high-Q circuits); atomically smooth walls, thereby reducing rf losses; and the ability to integrate active and passive devices directly in the waveguide on thin membranes, thereby solving the traditional problem of mounting thin substrates.

  19. Bioluminescent bioreporter integrated circuit

    DOEpatents

    Simpson, Michael L.; Sayler, Gary S.; Paulus, Michael J.

    2000-01-01

    Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

  20. The Global Circuit.

    ERIC Educational Resources Information Center

    Lansford, Henry

    1983-01-01

    Discusses the nature of and research related to a theory explaining the earth's electric budget. The theory suggests a global electric circuit completed by a positive current flowing up into thunderstorm clouds, from clouds to ionosphere, distributed around the globe, and down to earth through the lower atmosphere in fair-weather regions. (JN)

  1. A Step Circuit Program.

    ERIC Educational Resources Information Center

    Herman, Susan

    1995-01-01

    Aerobics instructors can use step aerobics to motivate students. One creative method is to add the step to the circuit workout. By incorporating the step, aerobic instructors can accommodate various fitness levels. The article explains necessary equipment and procedures, describing sample stations for cardiorespiratory fitness, muscular strength,…

  2. Circuit breaker lockout device

    DOEpatents

    Kozlowski, L.J.; Shirey, L.A.

    1992-11-24

    An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock block. Then a special scissors conforming to O.S.H.A. regulations can be installed, with one or more padlocks, on the lockout assembly to prevent removal of the lock pin from the lockout assembly, thereby preventing removal of the lockout assembly from the circuit breaker. 2 figs.

  3. Circuit breaker lockout device

    DOEpatents

    Kozlowski, Lawrence J.; Shirey, Lawrence A.

    1992-01-01

    An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock block. Then a special scissors conforming to O.S.H.A. regulations can be installed, with one or more padlocks, on the lockout assembly to prevent removal of the lock pin from the lockout assembly, thereby preventing removal of the lockout assembly from the circuit breaker.

  4. Energy management circuit

    SciTech Connect

    Corless, R. W.

    1985-10-15

    An energy management circuit for use in a telephone or other device which includes an electronic memory is disclosed. The invention provides a capacitive keep alive power supply to maintain said memory in an active condition during extended periods when the device is disconnected from a line power source, as in a telephone on-hook condition. A large capacitor charge is maintained within a predetermined voltage range during such disconnect conditions by a resistively coupled trickle charge power source. A comparator is operated to monitor capacitor charge and to produce a control signal when the voltage at the capacitor falls below a selected memory keep alive level. The control signal operates a switch to bypass the trickle charge circuit. The switch couples line power directly to the capacitor to charge the capacitor to a voltage sufficient to maintain memory contents intact. A switch inhibit circuit is provided to prevent trickle charge bypass during an inadequate or excessive line voltage condition. A sleep timer circuit is also provided to conserve energy required to operate the present invention by allowing the invention to operate periodically and only for short intervals.

  5. Automatic sweep circuit

    DOEpatents

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  6. "Printed-circuit" rectenna

    NASA Technical Reports Server (NTRS)

    Dickinson, R. M.

    1977-01-01

    Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.

  7. A coherent RC circuit

    NASA Astrophysics Data System (ADS)

    Gabelli, J.; Fève, G.; Berroir, J.-M.; Plaçais, B.

    2012-12-01

    We review the first experiment on dynamic transport in a phase-coherent quantum conductor. In our discussion, we highlight the use of time-dependent transport as a means of gaining insight into charge relaxation on a mesoscopic scale. For this purpose, we studied the ac conductance of a model quantum conductor, i.e. the quantum RC circuit. Prior to our experimental work, Büttiker et al (1993 Phys. Lett. A 180 364-9) first worked on dynamic mesoscopic transport in the 1990s. They predicted that the mesoscopic RC circuit can be described by a quantum capacitance related to the density of states in the capacitor and a constant charge-relaxation resistance equal to half of the resistance quantum h/2e2, when a single mode is transmitted between the capacitance and a reservoir. By applying a microwave excitation to a gate located on top of a coherent submicronic quantum dot that is coupled to a reservoir, we validate this theoretical prediction on the ac conductance of the quantum RC circuit. Our study demonstrates that the ac conductance is directly related to the dwell time of electrons in the capacitor. Thereby, we observed a counterintuitive behavior of a quantum origin: as the transmission of the single conducting mode decreases, the resistance of the quantum RC circuit remains constant while the capacitance oscillates.

  8. Electrifying Inquiry: Electrical Circuits

    ERIC Educational Resources Information Center

    Godbey, Susan; Barnett, Jessica; Webster, Lois

    2005-01-01

    An activity involving parallel electrical circuits was modified to incorporate an open inquiry approach. Both the original and revised versions of the activity were tested in the middle school classroom. We present a comparison of the two versions of the activity in terms of facilitating learning and engaging students' interests.

  9. Integrated circuit reliability testing

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Sayah, Hoshyar R. (Inventor)

    1990-01-01

    A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the measured length of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor. The percentage by which the measured length exceeds the design length, at which the integrated circuit will be discarded, depends on the required reliability of the integrated circuit.

  10. Integrated circuit reliability testing

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G. (Inventor); Sayah, Hoshyar R. (Inventor)

    1988-01-01

    A technique is described for use in determining the reliability of microscopic conductors deposited on an uneven surface of an integrated circuit device. A wafer containing integrated circuit chips is formed with a test area having regions of different heights. At the time the conductors are formed on the chip areas of the wafer, an elongated serpentine assay conductor is deposited on the test area so the assay conductor extends over multiple steps between regions of different heights. Also, a first test conductor is deposited in the test area upon a uniform region of first height, and a second test conductor is deposited in the test area upon a uniform region of second height. The occurrence of high resistances at the steps between regions of different height is indicated by deriving the measured length of the serpentine conductor using the resistance measured between the ends of the serpentine conductor, and comparing that to the design length of the serpentine conductor. The percentage by which the measured length exceeds the design length, at which the integrated circuit will be discarded, depends on the required reliability of the integrated circuit.

  11. Wein bridge oscillator circuit

    NASA Technical Reports Server (NTRS)

    Lipoma, P. C.

    1971-01-01

    Circuit with minimum number of components provides stable outputs of 2 to 8 volts at frequencies of .001 to 100 kHz. Oscillator exhibits low power consumption, portability, simplicity, and drive capability, it has application as loudspeaker tester and audible alarm, as well as in laboratory and test generators.

  12. Resistor Combinations for Parallel Circuits.

    ERIC Educational Resources Information Center

    McTernan, James P.

    1978-01-01

    To help simplify both teaching and learning of parallel circuits, a high school electricity/electronics teacher presents and illustrates the use of tables of values for parallel resistive circuits in which total resistances are whole numbers. (MF)

  13. Electronic circuits and systems: A compilation. [including integrated circuits, logic circuits, varactor diode circuits, low pass filters, and optical equipment circuits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Technological information is presented electronic circuits and systems which have potential utility outside the aerospace community. Topics discussed include circuit components such as filters, converters, and integrators, circuits designed for use with specific equipment or systems, and circuits designed primarily for use with optical equipment or displays.

  14. Methods of fabricating applique circuits

    DOEpatents

    Dimos, Duane B.; Garino, Terry J.

    1999-09-14

    Applique circuits suitable for advanced packaging applications are introduced. These structures are particularly suited for the simple integration of large amounts (many nanoFarads) of capacitance into conventional integrated circuit and multichip packaging technology. In operation, applique circuits are bonded to the integrated circuit or other appropriate structure at the point where the capacitance is required, thereby minimizing the effects of parasitic coupling. An immediate application is to problems of noise reduction and control in modern high-frequency circuitry.

  15. High voltage MOSFET switching circuit

    DOEpatents

    McEwan, T.E.

    1994-07-26

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET. 2 figs.

  16. Ladder-Type Circuits Revisited

    ERIC Educational Resources Information Center

    Yoon, Sung Hyun

    2007-01-01

    Ladder-type circuits where a given unit is repeated infinitely many times are dealt with in many textbooks on electromagnetism as examples of filter circuits. Determining the impedance of such circuits seems to be regarded as simple, which may be due to the fact that the invariance of the infinite system under the operation of adding one more unit…

  17. High voltage MOSFET switching circuit

    DOEpatents

    McEwan, Thomas E.

    1994-01-01

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  18. Neuromorphic silicon neuron circuits.

    PubMed

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin-Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  19. PHASE DIFFERENTIAL INDICATING CIRCUIT

    DOEpatents

    Kirsten, F.A.

    1962-01-01

    An electronic circuit for totalizing the net phase difference between two alternating current signals is designed which responds to both increasing and decreasing phase changes. A phase comparator provldes an output pulse for each 360 deg of phase difference occurring, there being a negative pulse for phase shtft in one direction and a positive pulse for a phase shift in the opposite direction. A counting circuit utilizing glow discharge tubes receives the negative and positive pulses at a single input terminal and provides a running net total, pulses of one polarity dded and pulses of the opposite polarity being subtracted. The glow discharge tubes may be decaded to increase the total count capacity. (AEC)

  20. LC-circuit calorimetry

    SciTech Connect

    Bossen, O.; Schilling, A.

    2011-09-15

    We present a new type of calorimeter in which we couple an unknown heat capacity with the aid of Peltier elements to an electrical circuit. The use of an electrical inductance and an amplifier in the circuit allows us to achieve autonomous oscillations, and the measurement of the corresponding resonance frequency makes it possible to accurately measure the heat capacity with an intrinsic statistical uncertainty that decreases as {approx}t{sub m}{sup -3/2} with measuring time t{sub m}, as opposed to a corresponding uncertainty {approx}t{sub m}{sup -1/2} in the conventional alternating current method to measure heat capacities. We have built a demonstration experiment to show the feasibility of the new technique, and we have tested it on a gadolinium sample at its transition to the ferromagnetic state.

  1. GAS PHOTOTUBE CIRCUIT

    DOEpatents

    Richardson, J.H.

    1958-03-01

    This patent pertains to electronic circuits for measuring the intensity of light and is especially concerned with measurement between preset light thresholds. Such a circuit has application in connection with devices for reading-out information stored on punch cards or tapes where the cards and tapes are translucent. By the novel arrangement of this invention thc sensitivity of a gas phototube is maintained at a low value when the light intensity is below a first threshold level. If the light level rises above the first threshold level, the tube is rendered highly sensitive and an output signal will vary in proportion to the light intensity change. When the light level decreases below a second threshold level, the gas phototube is automatically rendered highly insensitive. Each of these threshold points is adjustable.

  2. Neuromorphic Silicon Neuron Circuits

    PubMed Central

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  3. Power supply conditioning circuit

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Loveland, R.

    1987-01-01

    A power supply conditioning circuit that can reduce Periodic and Random Deviations (PARD) on the output voltages of dc power supplies to -150 dBV from dc to several KHz with no measurable periodic deviations is described. The PARD for a typical commercial low noise power supply is -74 dBV for frequencies above 20 Hz and is often much worse at frequencies below 20 Hz. The power supply conditioning circuit described here relies on the large differences in the dynamic impedances of a constant current diode and a zener diode to establish a dc voltage with low PARD. Power supplies with low PARD are especially important in circuitry involving ultrastable frequencies for the Deep Space Network.

  4. Monolithic Optoelectronic Integrated Circuit

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Walters, Wayne; Gustafsen, Jerry; Bendett, Mark

    1990-01-01

    Monolithic optoelectronic integrated circuit (OEIC) receives single digitally modulated input light signal via optical fiber and converts it into 16-channel electrical output signal. Potentially useful in any system in which digital data must be transmitted serially at high rates, then decoded into and used in parallel format at destination. Applications include transmission and decoding of control signals to phase shifters in phased-array antennas and also communication of data between computers and peripheral equipment in local-area networks.

  5. PARTICLE BEAM TRACKING CIRCUIT

    DOEpatents

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  6. Integrated Circuit Immunity

    NASA Technical Reports Server (NTRS)

    Sketoe, J. G.; Clark, Anthony

    2000-01-01

    This paper presents a DOD E3 program overview on integrated circuit immunity. The topics include: 1) EMI Immunity Testing; 2) Threshold Definition; 3) Bias Tee Function; 4) Bias Tee Calibration Set-Up; 5) EDM Test Figure; 6) EMI Immunity Levels; 7) NAND vs. and Gate Immunity; 8) TTL vs. LS Immunity Levels; 9) TP vs. OC Immunity Levels; 10) 7805 Volt Reg Immunity; and 11) Seventies Chip Set. This paper is presented in viewgraph form.

  7. All Spin Digital Circuits

    NASA Astrophysics Data System (ADS)

    Behin-Aein, Behtash; Datta, Deepanjan; Salahuddin, Sayeef; Datta, Supriyo

    2009-03-01

    Switching of a magnetic free layer using spin polarized current has been demonstrated in Magnetic Tunnel Junction (MTJ) devices. Currently MTJ's are being studied for memory and microwave oscillator applications. The purpose of this talk is to explore a modified MTJ where a clock pulse via the fixed layer facilities the switching of the free layer in accordance with a weak bias provided by an input magnet in the form of a spin current. Based on the Landau-Lifshitz-Gilbert equation (LLG) augmented with spin torque functions, we show the switching energy and the switching time of the free layer which indicates the possibility of very low power digital logic applications. Ordinary digital circuits store information in the form of capacitor charges that communicate through electrical interconnects. The purpose of this paper is to show that modified MTJ's can be the basis for all spin digital circuits. Our primary objective is to stimulate proof of concept experiments that could usher in a whole new set of devices suitable for spintronic circuits.

  8. Optical Circuit Switched Protocol

    NASA Technical Reports Server (NTRS)

    Monacos, Steve P. (Inventor)

    2000-01-01

    The present invention is a system and method embodied in an optical circuit switched protocol for the transmission of data through a network. The optical circuit switched protocol is an all-optical circuit switched network and includes novel optical switching nodes for transmitting optical data packets within a network. Each optical switching node comprises a detector for receiving the header, header detection logic for translating the header into routing information and eliminating the header, and a controller for receiving the routing information and configuring an all optical path within the node. The all optical path located within the node is solely an optical path without having electronic storage of the data and without having optical delay of the data. Since electronic storage of the header is not necessary and the initial header is eliminated by the first detector of the first switching node. multiple identical headers are sent throughout the network so that subsequent switching nodes can receive and read the header for setting up an optical data path.

  9. Driven superconducting quantum circuits

    NASA Astrophysics Data System (ADS)

    Nakamura, Yasunobu

    2014-03-01

    Driven nonlinear quantum systems show rich phenomena in various fields of physics. Among them, superconducting quantum circuits have very attractive features such as well-controlled quantum states with design flexibility, strong nonlinearity of Josephson junctions, strong coupling to electromagnetic driving fields, little internal dissipation, and tailored coupling to the electromagnetic environment. We have investigated properties and functionalities of driven superconducting quantum circuits. A transmon qubit coupled to a transmission line shows nearly perfect spatial mode matching between the incident and scattered microwave field in the 1D mode. Dressed states under a driving field are studied there and also in a semi-infinite 1D mode terminated by a resonator containing a flux qubit. An effective Λ-type three-level system is realized under an appropriate driving condition. It allows ``impedance-matched'' perfect absorption of incident probe photons and down conversion into another frequency mode. Finally, the weak signal from the qubit is read out using a Josephson parametric amplifier/oscillator which is another nonlinear circuit driven by a strong pump field. This work was partly supported by the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST), Project for Developing Innovation Systems of MEXT, MEXT KAKENHI ``Quantum Cybernetics,'' and the NICT Commissioned Research.

  10. Inkjet deposited circuit components

    NASA Astrophysics Data System (ADS)

    Bidoki, S. M.; Nouri, J.; Heidari, A. A.

    2010-05-01

    All-printed electronics as a means of achieving ultra-low-cost electronic circuits has attracted great interest in recent years. Inkjet printing is one of the most promising techniques by which the circuit components can be ultimately drawn (i.e. printed) onto the substrate in one step. Here, the inkjet printing technique was used to chemically deposit silver nanoparticles (10-200 nm) simply by ejection of silver nitrate and reducing solutions onto different substrates such as paper, PET plastic film and textile fabrics. The silver patterns were tested for their functionality to work as circuit components like conductor, resistor, capacitor and inductor. Different levels of conductivity were achieved simply by changing the printing sequence, inks ratio and concentration. The highest level of conductivity achieved by an office thermal inkjet printer (300 dpi) was 5.54 × 105 S m-1 on paper. Inkjet deposited capacitors could exhibit a capacitance of more than 1.5 nF (parallel plate 45 × 45 mm2) and induction coils displayed an inductance of around 400 µH (planar coil 10 cm in diameter). Comparison of electronic performance of inkjet deposited components to the performance of conventionally etched items makes the technique highly promising for fabricating different printed electronic devices.

  11. Fundamental Atomtronic Circuit Elements

    NASA Astrophysics Data System (ADS)

    Lee, Jeffrey; McIlvain, Brian; Lobb, Christopher; Hill, Wendell T., III

    2012-06-01

    Recent experiments with neutral superfluid gases have shown that it is possible to create atomtronic circuits analogous to existing superconducting circuits. The goals of these experiments are to create complex systems such as Josephson junctions. In addition, there are theoretical models for active atomtronic components analogous to diodes, transistors and oscillators. In order for any of these devices to function, an understanding of the more fundamental atomtronic elements is needed. Here we describe the first experimental realization of these more fundamental elements. We have created an atomtronic capacitor that is discharged through a resistance and inductance. We will discuss a theoretical description of the system that allows us to determine values for the capacitance, resistance and inductance. The resistance is shown to be analogous to the Sharvin resistance, and the inductance analogous to kinetic inductance in electronics. This atomtronic circuit is implemented with a thermal sample of laser cooled rubidium atoms. The atoms are confined using what we call free-space atom chips, a novel optical dipole trap produced using a generalized phase-contrast imaging technique. We will also discuss progress toward implementing this atomtronic system in a degenerate Bose gas.

  12. Coating Circuit Boards With Silicone

    NASA Technical Reports Server (NTRS)

    Gaudiano, S.

    1986-01-01

    Techniques appropriate to boards containing CMOS circuits detailed. Document presents procedure for applying thin conformal coating to such electronic assemblies as printed-circuit boards and wire-wrapped boards. Coating is from 1 to 7 mils (25 to 178 micrometers) thick and composed of room-temperature-vulcanizing (RTV) silicone. Specifies materials, equipment, spraying method, and quality requirements. Takes into account special needs of circuits made with complementary metal-oxide/semiconductor (CMOS) devices on circuit boards. Special attention given to preventing damage by electrostatic discharge, to which CMOS circuits especially sensitive.

  13. Power system with an integrated lubrication circuit

    SciTech Connect

    Hoff, Brian D.; Akasam, Sivaprasad; Algrain, Marcelo C.; Johnson, Kris W.; Lane, William H.

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  14. Integrated coherent matter wave circuits

    NASA Astrophysics Data System (ADS)

    Ryu, C.; Boshier, M. G.

    2015-09-01

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. Here we report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. The source of coherent matter waves is a Bose-Einstein condensate (BEC). We launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry.

  15. Memristor based startup circuit for self biased circuits

    NASA Astrophysics Data System (ADS)

    Das, Mangal; Singh, Amit Kumar; Rathi, Amit; Singhal, Sonal

    2016-04-01

    This paper presents the design of a Memristor based startup circuit for self biased circuits. Memristor has many advantages over conventional CMOS devices such as low leakage current at nanometer scale, easy to manufacture. In this work the switching characteristics of memristor is utilized. First the theoretical equations describing the switching behavior of memristor are investigated. To prove the switching capability of Memristor, a startup circuit based on memristor is proposed which uses series combination of Memristor and capacitor. Proposed circuit is compared with the previously reported MOSFET based startup circuits. Comparison of different circuits was done to validate the results. Simulation results show that memristor based circuit can attain on (I = 12.94 µA) to off state (I = 1 .2 µA) in 25 ns while the MOSFET based startup circuits take on (I = 14.19 µA) to off state (I = 1.4 µA) in more than 90 ns. The benefit comes in terms of area because the number of components used in the circuit are lesser than the conventional startup circuits.

  16. Dynamic pulse difference circuit

    DOEpatents

    Erickson, Gerald L.

    1978-01-01

    A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the up-down counter provides a signal upon overflow of the counter.

  17. Base drive circuit

    DOEpatents

    Lange, A.C.

    1995-04-04

    An improved base drive circuit having a level shifter for providing bistable input signals to a pair of non-linear delays. The non-linear delays provide gate control to a corresponding pair of field effect transistors through a corresponding pair of buffer components. The non-linear delays provide delayed turn-on for each of the field effect transistors while an associated pair of transistors shunt the non-linear delays during turn-off of the associated field effect transistor. 2 figures.

  18. Biophotonic integrated circuits

    NASA Astrophysics Data System (ADS)

    Cohen, Daniel A.; Nolde, Jill A.; Wang, Chad S.; Skogen, Erik J.; Rivlin, A.; Coldren, Larry A.

    2004-12-01

    Biosensors rely on optical techniques to obtain high sensitivity and speed, but almost all biochips still require external light sources, optics, and detectors, which limits the widespread use of these devices. The optoelectronics technology base now allows monolithic integration of versatile optical sources, novel sensing geometries, filters, spectrometers, and detectors, enabling highly integrated chip-scale sensors. We discuss biophotonic integrated circuits built on both GaAs and InP substrates, incorporating widely tunable lasers, novel evanescent field sensing waveguides, heterodyne spectrometers, and waveguide photodetectors, suitable for high sensitivity transduction of affinity assays.

  19. Digital Optical Circuit Technology

    NASA Technical Reports Server (NTRS)

    Dove, B. L. (Editor)

    1985-01-01

    The Proceedings for the 48th Meeting of the AGARD Avionics Panel contain the 18 papers presented a Technical Evaluation Report, and discussions that followed the presentations of papers. Seven papers were presented in the session devoted to optical bistability. Optical logic was addressed by three papers. The session on sources, modulators and demodulators presented three papers. Five papers were given in the final session on all optical systems. The purpose of this Specialists' Meeting was to present the research and development status of digital optical circuit technology and to examine its relevance in the broad context of digital processing, communication, radar, avionics and flight control systems implementation.

  20. Photonic Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Merritt, Scott; Krainak, Michael

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  1. Base drive circuit

    DOEpatents

    Lange, Arnold C.

    1995-01-01

    An improved base drive circuit (10) having a level shifter (24) for providing bistable input signals to a pair of non-linear delays (30, 32). The non-linear delays (30, 32) provide gate control to a corresponding pair of field effect transistors (100, 106) through a corresponding pair of buffer components (88, 94). The non-linear delays (30, 32) provide delayed turn-on for each of the field effect transistors (100, 106) while an associated pair of transistors (72, 80) shunt the non-linear delays (30, 32) during turn-off of the associated field effect transistor (100, 106).

  2. Seeing Circuits Assemble

    PubMed Central

    Lichtman, Jeff W.; Smith, Stephen J.

    2009-01-01

    Developmental neurobiology has been greatly invigorated by a recent string of breakthroughs in molecular biology and optical physics that permit direct in vivo observation of neural circuit assembly. The imaging done thus far suggests that as brains are built, a significant amount of unbuilding is also occurring. We offer the view that this tumult is the result of the intersecting behaviors of the many single-celled creatures (i.e., neurons, glia, and progenitors) that inhabit brains. New tools will certainly be needed if we wish to monitor the myriad cooperative and competitive interactions at play in the cellular society that builds brains. PMID:18995818

  3. Itch Mechanisms and Circuits

    PubMed Central

    Han, Liang; Dong, Xinzhong

    2014-01-01

    The itch-scratch reflex serves as a protective mechanism in everyday life. However, chronic persistent itching can be devastating. Despite the clinical importance of the itch sensation, its mechanism remains elusive. In the past decade, substantial progress has been made to uncover the mystery of itching. Here, we review the molecules, cells, and circuits known to mediate the itch sensation, which, coupled with advances in understanding the pathophysiology of chronic itching conditions, will hopefully contribute to the development of new anti-itch therapies. PMID:24819620

  4. Integrated circuit cell library

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)

    2005-01-01

    According to the invention, an ASIC cell library for use in creation of custom integrated circuits is disclosed. The ASIC cell library includes some first cells and some second cells. Each of the second cells includes two or more kernel cells. The ASIC cell library is at least 5% comprised of second cells. In various embodiments, the ASIC cell library could be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more comprised of second cells.

  5. Optically controllable molecular logic circuits

    NASA Astrophysics Data System (ADS)

    Nishimura, Takahiro; Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    2015-07-01

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.

  6. Optically controllable molecular logic circuits

    SciTech Connect

    Nishimura, Takahiro Fujii, Ryo; Ogura, Yusuke; Tanida, Jun

    2015-07-06

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.

  7. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    DOEpatents

    Clark, Lawrence T.; McIver, III, John K.

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  8. Time in Cortical Circuits

    PubMed Central

    Shadlen, Michael N.; Jazayeri, Mehrdad; Nobre, Anna C.; Buonomano, Dean V.

    2015-01-01

    Time is central to cognition. However, the neural basis for time-dependent cognition remains poorly understood. We explore how the temporal features of neural activity in cortical circuits and their capacity for plasticity can contribute to time-dependent cognition over short time scales. This neural activity is linked to cognition that operates in the present or anticipates events or stimuli in the near future. We focus on deliberation and planning in the context of decision making as a cognitive process that integrates information across time. We progress to consider how temporal expectations of the future modulate perception. We propose that understanding the neural basis for how the brain tells time and operates in time will be necessary to develop general models of cognition. SIGNIFICANCE STATEMENT Time is central to cognition. However, the neural basis for time-dependent cognition remains poorly understood. We explore how the temporal features of neural activity in cortical circuits and their capacity for plasticity can contribute to time-dependent cognition over short time scales. We propose that understanding the neural basis for how the brain tells time and operates in time will be necessary to develop general models of cognition. PMID:26468192

  9. Noise in biological circuits

    SciTech Connect

    Simpson, Michael L; Allen, Michael S.; Cox, Chris D.; Dar, Roy D.; Karig, David K; McCollum, James M.; Cooke, John F

    2009-01-01

    Noise biology focuses on the sources, processing, and biological consequences of the inherent stochastic fluctuations in molecular transitions or interactions that control cellular behavior. These fluctuations are especially pronounced in small systems where the magnitudes of the fluctuations approach or exceed the mean value of the molecular population. Noise biology is an essential component of nanomedicine where the communication of information is across a boundary that separates small synthetic and biological systems that are bound by their size to reside in environments of large fluctuations. Here we review the fundamentals of the computational, analytical, and experimental approaches to noise biology. We review results that show that the competition between the benefits of low noise and those of low population has resulted in the evolution of genetic system architectures that produce an uneven distribution of stochasticity across the molecular components of cells and, in some cases, use noise to drive biological function. We review the exact and approximate approaches to gene circuit noise analysis and simulation, and reviewmany of the key experimental results obtained using flow cytometry and time-lapse fluorescent microscopy. In addition, we consider the probative value of noise with a discussion of using measured noise properties to elucidate the structure and function of the underlying gene circuit. We conclude with a discussion of the frontiers of and significant future challenges for noise biology.

  10. Quasi-Linear Circuit

    NASA Technical Reports Server (NTRS)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  11. Jitter compensation circuit

    DOEpatents

    Sullivan, J.S.; Ball, D.G.

    1997-09-09

    The instantaneous V{sub co} signal on a charging capacitor is sampled and the charge voltage on capacitor C{sub o} is captured just prior to its discharge into the first stage of magnetic modulator. The captured signal is applied to an averaging circuit with a long time constant and to the positive input terminal of a differential amplifier. The averaged V{sub co} signal is split between a gain stage (G = 0.975) and a feedback stage that determines the slope of the voltage ramp applied to the high speed comparator. The 97.5% portion of the averaged V{sub co} signal is applied to the negative input of a differential amplifier gain stage (G = 10). The differential amplifier produces an error signal by subtracting 97.5% of the averaged V{sub co} signal from the instantaneous value of sampled V{sub co} signal and multiplying the difference by ten. The resulting error signal is applied to the positive input of a high speed comparator. The error signal is then compared to a voltage ramp that is proportional to the averaged V{sub co} values squared divided by the total volt-second product of the magnetic compression circuit. 11 figs.

  12. Jitter compensation circuit

    DOEpatents

    Sullivan, James S.; Ball, Don G.

    1997-01-01

    The instantaneous V.sub.co signal on a charging capacitor is sampled and the charge voltage on capacitor C.sub.o is captured just prior to its discharge into the first stage of magnetic modulator. The captured signal is applied to an averaging circuit with a long time constant and to the positive input terminal of a differential amplifier. The averaged V.sub. co signal is split between a gain stage (G=0.975) and a feedback stage that determines the slope of the voltage ramp applied to the high speed comparator. The 97.5% portion of the averaged V.sub.co signal is applied to the negative input of a differential amplifier gain stage (G=10). The differential amplifier produces an error signal by subtracting 97.5% of the averaged V.sub.co signal from the instantaneous value of sampled V.sub.co signal and multiplying the difference by ten. The resulting error signal is applied to the positive input of a high speed comparator. The error signal is then compared to a voltage ramp that is proportional to the averaged V.sub.co values squared divided by the total volt-second product of the magnetic compression circuit.

  13. Simple Cell Balance Circuit

    NASA Technical Reports Server (NTRS)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  14. A bit serial sequential circuit

    NASA Technical Reports Server (NTRS)

    Hu, S.; Whitaker, S.

    1990-01-01

    Normally a sequential circuit with n state variables consists of n unique hardware realizations, one for each state variable. All variables are processed in parallel. This paper introduces a new sequential circuit architecture that allows the state variables to be realized in a serial manner using only one next state logic circuit. The action of processing the state variables in a serial manner has never been addressed before. This paper presents a general design procedure for circuit construction and initialization. Utilizing pass transistors to form the combinational next state forming logic in synchronous sequential machines, a bit serial state machine can be realized with a single NMOS pass transistor network connected to shift registers. The bit serial state machine occupies less area than other realizations which perform parallel operations. Moreover, the logical circuit of the bit serial state machine can be modified by simply changing the circuit input matrix to develop an adaptive state machine.

  15. Automated Design of Quantum Circuits

    NASA Technical Reports Server (NTRS)

    Williams, Colin P.; Gray, Alexander G.

    2000-01-01

    In order to design a quantum circuit that performs a desired quantum computation, it is necessary to find a decomposition of the unitary matrix that represents that computation in terms of a sequence of quantum gate operations. To date, such designs have either been found by hand or by exhaustive enumeration of all possible circuit topologies. In this paper we propose an automated approach to quantum circuit design using search heuristics based on principles abstracted from evolutionary genetics, i.e. using a genetic programming algorithm adapted specially for this problem. We demonstrate the method on the task of discovering quantum circuit designs for quantum teleportation. We show that to find a given known circuit design (one which was hand-crafted by a human), the method considers roughly an order of magnitude fewer designs than naive enumeration. In addition, the method finds novel circuit designs superior to those previously known.

  16. Source-circuit design overview

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1983-01-01

    The source circuit is the fundamental electrical building block of a large central-station array; it consists of a series-parallel network of solar cells that develops full system voltage. The array field is generally made up of a large number of parallel source circuits. Source-circuit electrical configuration is driven by a number of design considerations, which must be considered simultaneously. Array fault tolerance and hot spot heating endurance are examined in detail.

  17. Audio distribution and Monitoring Circuit

    NASA Technical Reports Server (NTRS)

    Kirkland, J. M.

    1983-01-01

    Versatile circuit accepts and distributes TV audio signals. Three-meter audio distribution and monitoring circuit provides flexibility in monitoring, mixing, and distributing audio inputs and outputs at various signal and impedance levels. Program material is simultaneously monitored on three channels, or single-channel version built to monitor transmitted or received signal levels, drive speakers, interface to building communications, and drive long-line circuits.

  18. Power-Supply-Conditioning Circuit

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Loveland, R. C.

    1989-01-01

    Fluctuations of voltage suppressed in power supplies for precise radio-frequency circuits. Circuit suppresses both periodic and random deviations of dc supply voltage from desired steady level. Highly-stable feedback voltage regulator, conditioner intended in conjunction with conventional power-supply circuit to provide constant voltage to atomic frequency standard or other precise oscillator. Without conditioners, outputs of most commercial power supplies contain fluctuations causing unacceptably-large phase and amplitude modulation of precise oscillators.

  19. Electronic control circuits: A compilation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A compilation of technical R and D information on circuits and modular subassemblies is presented as a part of a technology utilization program. Fundamental design principles and applications are given. Electronic control circuits discussed include: anti-noise circuit; ground protection device for bioinstrumentation; temperature compensation for operational amplifiers; hybrid gatling capacitor; automatic signal range control; integrated clock-switching control; and precision voltage tolerance detector.

  20. Four-junction superconducting circuit.

    PubMed

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J Q

    2016-01-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

  1. PRECISION TIME-DELAY CIRCUIT

    DOEpatents

    Creveling, R.

    1959-03-17

    A tine-delay circuit which produces a delay time in d. The circuit a capacitor, an te back resistance, connected serially with the anode of the diode going to ground. At the start of the time delay a negative stepfunction is applied to the series circuit and initiates a half-cycle transient oscillatory voltage terminated by a transient oscillatory voltage of substantially higher frequency. The output of the delay circuit is taken at the junction of the inductor and diode where a sudden voltage rise appears after the initiation of the higher frequency transient oscillations.

  2. Four-junction superconducting circuit

    NASA Astrophysics Data System (ADS)

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

    2016-06-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit.

  3. Magnetic compression laser driving circuit

    DOEpatents

    Ball, D.G.; Birx, D.; Cook, E.G.

    1993-01-05

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  4. Magnetic compression laser driving circuit

    DOEpatents

    Ball, Don G.; Birx, Dan; Cook, Edward G.

    1993-01-01

    A magnetic compression laser driving circuit is disclosed. The magnetic compression laser driving circuit compresses voltage pulses in the range of 1.5 microseconds at 20 Kilovolts of amplitude to pulses in the range of 40 nanoseconds and 60 Kilovolts of amplitude. The magnetic compression laser driving circuit includes a multi-stage magnetic switch where the last stage includes a switch having at least two turns which has larger saturated inductance with less core material so that the efficiency of the circuit and hence the laser is increased.

  5. Four-junction superconducting circuit

    PubMed Central

    Qiu, Yueyin; Xiong, Wei; He, Xiao-Ling; Li, Tie-Fu; You, J. Q.

    2016-01-01

    We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its advantages over the latter. Moreover, the four-junction circuit in the single-well regime is also investigated. Our theory provides a tool to explore the physical properties of this four-junction superconducting circuit. PMID:27356619

  6. A Circuit to Demonstrate Phase Relationships in "RLC" Circuits

    ERIC Educational Resources Information Center

    Sokol, P. E.; Warren, G.; Zheng, B.; Smith, P.

    2013-01-01

    We have developed a circuit to demonstrate the phase relationships between resistive and reactive elements in series "RLC" circuits. We utilize a differential amplifier to allow the phases of the three elements and the current to be simultaneously displayed on an inexpensive four channel oscilloscope. We have included a novel circuit…

  7. ELECTRONIC PULSE SCALING CIRCUITS

    DOEpatents

    Cooke-Yarborough, E.H.

    1958-11-18

    Electronic pulse scaling circults of the klnd comprlsing a serles of bi- stable elements connected ln sequence, usually in the form of a rlng so as to be cycllcally repetitive at the highest scallng factor, are described. The scaling circuit comprises a ring system of bi-stable elements each arranged on turn-off to cause, a succeeding element of the ring to be turned-on, and one being arranged on turn-off to cause a further element of the ring to be turned-on. In addition, separate means are provided for applying a turn-off pulse to all the elements simultaneously, and for resetting the elements to a starting condition at the end of each cycle.

  8. Laser diode protection circuit

    SciTech Connect

    Burgyan, L.; Hand, W.L.

    1990-05-08

    This patent describes a method for protecting a laser diode included within an electro-optical circuit. It comprises: the laser diode, a DC bias supply for supplying forward conduction current to the laser diode to cause it to emit light energy at a predetermined quiescent operating point, and an RF amplifier means for supplying an RF amplitude of an analog modulating signal to the laser diode for modulating the intensity of the emitted light energy about the quiescent operating point thereof, the method including providing a very high impedance to the laser diode during its nominal operating conditions about the quiescent point and, sensing an instantaneous amplitude of the RF amplitude modulating signal to detect amplitude surges therein, and responding to the sensing means by removing forward conduction current from the laser diode during the sense amplitude surges int he RF amplitude of the analog modulating signal, thereby causing the laser diode to reduce emission of light energy to a safe level.

  9. Modeling cortical circuits.

    SciTech Connect

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  10. ELECTRONIC INTEGRATING CIRCUIT

    DOEpatents

    Englemann, R.H.

    1963-08-20

    An electronic integrating circuit using a transistor with a capacitor connected between the emitter and collector through which the capacitor discharges at a rate proportional to the input current at the base is described. Means are provided for biasing the base with an operating bias and for applying a voltage pulse to the capacitor for charging to an initial voltage. A current dividing diode is connected between the base and emitter of the transistor, and signal input terminal means are coupled to the juncture of the capacitor and emitter and to the base of the transistor. At the end of the integration period, the residual voltage on said capacitor is less by an amount proportional to the integral of the input signal. Either continuous or intermittent periods of integration are provided. (AEC)

  11. Photoconductive circuit element reflectometer

    DOEpatents

    Rauscher, C.

    1987-12-07

    A photoconductive reflectometer for characterizing semiconductor devices at millimeter wavelength frequencies where a first photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short first laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test. Second PCEs are connected along the transmission line to sample the signals on the transmission line when excited into conductance by short second laser light pulses, spaced apart in time a determinable period from the first laser light pulses. Electronic filters connected to each of the second PCEs act as low-pass filters and remove parasitic interference from the sampled signals and output the sampled signals in the form of slowed-motion images of the signals on the transmission line. 4 figs.

  12. Photoconductive circuit element reflectometer

    DOEpatents

    Rauscher, Christen

    1990-01-01

    A photoconductive reflectometer for characterizing semiconductor devices at millimeter wavelength frequencies where a first photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short first laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test. Second PCEs are connected along the transmission line to sample the signals on the transmission line when excited into conductance by short second laser light pulses, spaced apart in time a variable period from the first laser light pulses. Electronic filters connected to each of the second PCEs act as low-pass filters and remove parasitic interference from the sampled signals and output the sampled signals in the form of slowed-motion images of the signals on the transmission line.

  13. VLSI circuits implementing computational models of neocortical circuits.

    PubMed

    Wijekoon, Jayawan H B; Dudek, Piotr

    2012-09-15

    This paper overviews the design and implementation of three neuromorphic integrated circuits developed for the COLAMN ("Novel Computing Architecture for Cognitive Systems based on the Laminar Microcircuitry of the Neocortex") project. The circuits are implemented in a standard 0.35 μm CMOS technology and include spiking and bursting neuron models, and synapses with short-term (facilitating/depressing) and long-term (STDP and dopamine-modulated STDP) dynamics. They enable execution of complex nonlinear models in accelerated-time, as compared with biology, and with low power consumption. The neural dynamics are implemented using analogue circuit techniques, with digital asynchronous event-based input and output. The circuits provide configurable hardware blocks that can be used to simulate a variety of neural networks. The paper presents experimental results obtained from the fabricated devices, and discusses the advantages and disadvantages of the analogue circuit approach to computational neural modelling. PMID:22342970

  14. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  15. Postirradiation Effects In Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Shaw, David C.; Barnes, Charles E.

    1993-01-01

    Two reports discuss postirradiation effects in integrated circuits. Presents examples of postirradiation measurements of performances of integrated circuits of five different types: dual complementary metal oxide/semiconductor (CMOS) flip-flop; CMOS analog multiplier; two CMOS multiplying digital-to-analog converters; electrically erasable programmable read-only memory; and semiconductor/oxide/semiconductor octal buffer driver.

  16. Demonstrations with an "LCR" Circuit

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2011-01-01

    The "LCR" circuit is an important topic in the course of electricity and magnetism. Papers in this field consider mainly the forced oscillations and resonance. Our aim is to show how to demonstrate the free and self-excited oscillations in an "LCR" circuit. (Contains 4 figures.)

  17. Compact Circuit Preprocesses Accelerometer Output

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  18. Hybrid temperature-monitoring circuit

    NASA Technical Reports Server (NTRS)

    Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

    1979-01-01

    Hybrid circuit developed for use in hand-held vital signs monitor converts resistance of thermistor probe to 3 1/2 digit BCD (binary-coded-decimal) temperature readout. If used alone circuit can form 'stand alone' temperature monitor or can transmit temperature data via telemetry to data acquisition systems.

  19. Time domain analog circuit simulation

    NASA Astrophysics Data System (ADS)

    Fijnvandraat, J. G.; Houben, S. H. M. J.; Ter Maten, E. J. W.; Peters, J. M. F.

    2006-01-01

    Recent developments of new methods for simulating electric circuits are described. Emphasis is put on methods that fit existing datastructures for backward differentiation formulae methods. These methods can be modified to apply to hierarchically organized datastructures, which allows for efficient simulation of large designs of circuits in the electronics industry.

  20. Pharmacokinetics and "RC" Circuit Concepts

    ERIC Educational Resources Information Center

    De Cock, Mieke; Janssen, Paul

    2013-01-01

    Most introductory physics courses include a chapter on "RC" circuits in which the differential equations for the charging and discharging of a capacitor are derived. A number of papers in this journal describe lab experiments dealing with the measurement of different parameters in such "RC" circuits. In this contribution, we…

  1. Dive In to Aquatic Circuits.

    ERIC Educational Resources Information Center

    Goldfarb, Joseph M.

    1995-01-01

    The article presents a method for swimming teachers and coaches to stave off workout boredom in their students by using a circuit in the pool. After explaining how to set up a training circuit, the article describes sample stations and notes important safety precautions. (SM)

  2. Digital circuits using universal logic gates

    NASA Technical Reports Server (NTRS)

    Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor); Cameron, Eric G. (Inventor); Donohoe, Gregory W. (Inventor); Gambles, Jody W. (Inventor)

    2004-01-01

    According to the invention, a digital circuit design embodied in at least one of a structural netlist, a behavioral netlist, a hardware description language netlist, a full-custom ASIC, a semi-custom ASIC, an IP core, an integrated circuit, a hybrid of chips, one or more masks, a FPGA, and a circuit card assembly is disclosed. The digital circuit design includes first and second sub-circuits. The first sub-circuits comprise a first percentage of the digital circuit design and the second sub-circuits comprise a second percentage of the digital circuit design. Each of the second sub-circuits is substantially comprised of one or more kernel circuits. The kernel circuits are comprised of selection circuits. The second percentage is at least 5%. In various embodiments, the second percentage could be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%.

  3. Genetic Dissection of Neural Circuits

    PubMed Central

    Luo, Liqun; Callaway, Edward M.; Svoboda, Karel

    2009-01-01

    Understanding the principles of information processing in neural circuits requires systematic characterization of the participating cell types and their connections, and the ability to measure and perturb their activity. Genetic approaches promise to bring experimental access to complex neural systems, including genetic stalwarts such as the fly and mouse, but also to nongenetic systems such as primates. Together with anatomical and physiological methods, cell-type-specific expression of protein markers and sensors and transducers will be critical to construct circuit diagrams and to measure the activity of genetically defined neurons. Inactivation and activation of genetically defined cell types will establish causal relationships between activity in specific groups of neurons, circuit function, and animal behavior. Genetic analysis thus promises to reveal the logic of the neural circuits in complex brains that guide behaviors. Here we review progress in the genetic analysis of neural circuits and discuss directions for future research and development. PMID:18341986

  4. Demultiplexer circuit for neural stimulation

    DOEpatents

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  5. Twin reservoir heat transfer circuit

    SciTech Connect

    Urch, J.F.

    1986-09-23

    This patent describes a heat transfer means comprising circuitry defining a closed flow path for working fluid; a primary circuit forming part of the path and having two ends at one of which the working fluid is at a high pressure and at the other of which the working fluid is at a low pressure. The circuitry defines a fluid supply reservoir and a fluid collection reservoir disposed respectively at the two ends; ejector means in the primary circuit; a drive fluid inlet, and exhaust outlet and a suction inlet provided on the ejector means. Also included are a branch circuit bridging a section of the primary circuit and an outlet end of the branch circuit connected to the suction inlet of the ejector means.

  6. Electronic design with integrated circuits

    NASA Astrophysics Data System (ADS)

    Comer, D. J.

    The book is concerned with the application of integrated circuits and presents the material actually needed by the system designer to do an effective job. The operational amplifier (op amp) is discussed, taking into account the electronic amplifier, the basic op amp, the practical op amp, analog applications, and digital applications. Digital components are considered along with combinational logic, digital subsystems, the microprocessor, special circuits, communications, and integrated circuit building blocks. Attention is given to logic gates, logic families, multivibrators, the digital computer, digital methods, communicating with a computer, computer organization, register and timing circuits for data transfer, arithmetic circuits, memories, the microprocessor chip, the control unit, communicating with the microprocessor, examples of microprocessor architecture, programming a microprocessor, the voltage-controlled oscillator, the phase-locked loop, analog-to-digital conversion, amplitude modulation, frequency modulation, pulse and digital transmission, the semiconductor diode, the bipolar transistor, and the field-effect transistor.

  7. 49 CFR 236.728 - Circuit, trap.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, trap. 236.728 Section 236.728... Circuit, trap. A term applied to a circuit used where it is desirable to provide a track circuit but where it is impracticable to maintain a track circuit....

  8. An Electronics Course Emphasizing Circuit Design

    ERIC Educational Resources Information Center

    Bergeson, Haven E.

    1975-01-01

    Describes a one-quarter introductory electronics course in which the students use a variety of inexpensive integrated circuits to design and construct a large number of useful circuits. Presents the subject matter of the course in three parts: linear circuits, digital circuits, and more complex circuits. (GS)

  9. Gate drive latching circuit for an auxiliary resonant commutation circuit

    NASA Technical Reports Server (NTRS)

    Delgado, Eladio Clemente (Inventor); Kheraluwala, Mustansir Hussainy (Inventor)

    1999-01-01

    A gate drive latching circuit for an auxiliary resonant commutation circuit for a power switching inverter includes a current monitor circuit providing a current signal to a pair of analog comparators to implement latching of one of a pair of auxiliary switching devices which are used to provide commutation current for commutating switching inverters in the circuit. Each of the pair of comparators feeds a latching circuit which responds to an active one of the comparators for latching the associated gate drive circuit for one of the pair of auxiliary commutating switches. An initial firing signal is applied to each of the commutating switches to gate each into conduction and the resulting current is monitored to determine current direction and therefore the one of the switches which is carrying current. The comparator provides a latching signal to the one of the auxiliary power switches which is actually conducting current and latches that particular power switch into an on state for the duration of current through the device. The latching circuit is so designed that the only time one of the auxiliary switching devices can be latched on is during the duration of an initial firing command signal.

  10. A circuit to demonstrate phase relationships in RLC circuits

    NASA Astrophysics Data System (ADS)

    Sokol, P. E.; Warren, G.; Zheng, B.; Smith, P.

    2013-05-01

    We have developed a circuit to demonstrate the phase relationships between resistive and reactive elements in series RLC circuits. We utilize a differential amplifier to allow the phases of the three elements and the current to be simultaneously displayed on an inexpensive four channel oscilloscope. We have included a novel circuit that provides a visual indication of the magnitude and direction of the voltage or current using LEDs. This allows the phase relationships to be demonstrated directly using the very intuitive measurement of the brightness of a light.

  11. Nanofluidic Transistor Circuits

    NASA Astrophysics Data System (ADS)

    Chang, Hsueh-Chia; Cheng, Li-Jing; Yan, Yu; Slouka, Zdenek; Senapati, Satyajyoti

    2012-02-01

    Non-equilibrium ion/fluid transport physics across on-chip membranes/nanopores is used to construct rectifying, hysteretic, oscillatory, excitatory and inhibitory nanofluidic elements. Analogs to linear resistors, capacitors, inductors and constant-phase elements were reported earlier (Chang and Yossifon, BMF 2009). Nonlinear rectifier is designed by introducing intra-membrane conductivity gradient and by asymmetric external depletion with a reverse rectification (Yossifon and Chang, PRL, PRE, Europhys Lett 2009-2011). Gating phenomenon is introduced by functionalizing polyelectrolytes whose conformation is field/pH sensitive (Wang, Chang and Zhu, Macromolecules 2010). Surface ion depletion can drive Rubinstein's microvortex instability (Chang, Yossifon and Demekhin, Annual Rev of Fluid Mech, 2012) or Onsager-Wien's water dissociation phenomenon, leading to two distinct overlimiting I-V features. Bipolar membranes exhibit an S-hysteresis due to water dissociation (Cheng and Chang, BMF 2011). Coupling the hysteretic diode with some linear elements result in autonomous ion current oscillations, which undergo classical transitions to chaos. Our integrated nanofluidic circuits are used for molecular sensing, protein separation/concentration, electrospray etc.

  12. Piezo-optomechanical circuits

    NASA Astrophysics Data System (ADS)

    Coimbatore Balram, Krishna; Davanco, Marcelo; Ilic, B. Robert; Srinivasan, Kartik

    Coherent links between the optical, radio frequency (RF), and mechanical domains are critical for applications ranging from quantum state transfer between the RF and optical domains to signal processing in the acoustic domain for microwave photonics. We develop such a piezo optomechanical circuit platform in GaAs, in which localized and interacting 1550 nm photons and 2.4 GHz phonons are combined with photonic and phononic waveguides. GaAs allows us to exploit the photoelastic effect to engineer cavities with strong optomechanical coupling (g0/2 π ~ 1.1 MHz) and the piezoelectric effect to couple RF fields to mechanical motion through surface acoustic waves, which are routed on-chip using phononic crystal waveguides. This platform enables optical readout of electrically-injected mechanical states with an average coherent intracavity phonon number as small as ~0.05 and the ability to drive mechanical motion with equal facility through either the optical or electrical channel. This is used to demonstrate a novel acoustic wave interference effect in which optically-driven motion is completely cancelled by electrically-driven motion, and vice versa. As an application of this, we present time-domain measurements of optically-controlled acoustic pulse propagation. Secondary Affiliation is Maryland Nanocenter, University of Maryland, College Park, MD.

  13. PHOTOSENSITIVE RELAY CONTROL CIRCUIT

    DOEpatents

    Martin, C.F.

    1958-01-14

    adapted for the measurement of the time required for an oscillating member to pass through a preselected number of oscillations, after being damped to a certain maximum amplitude of oscillation. A mirror is attached to the moving member and directs light successively to a photocell which is part of a trigger unit and to first and second photocells which are part of a starter unit, as the member swings to its maximum amplitude. The starter and trigger units comprise thyratrons and relays so interconnected that the trigger circuit, although generating a counter pulse, does not register a count in the counter when the light traverses both photocells of the starter unit. When the amplitude of oscillation of the member decreases to where the second photocell is not transversed, the triggei pulse is received by the counter. The counter taen operates to register the desired number of oscillations and initiates and terminates a timer for measuring the time irterval for the preselected number of oscillations.

  14. Variational integrators for electric circuits

    SciTech Connect

    Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

    2013-06-01

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator.

  15. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2014-10-01 2014-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  16. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2013-10-01 2013-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  17. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  18. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2011-10-01 2011-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  19. 49 CFR 236.731 - Controller, circuit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Controller, circuit. A device for opening and closing electric circuits. ... 49 Transportation 4 2012-10-01 2012-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  20. Performance analysis of electrical circuits /PANE/

    NASA Technical Reports Server (NTRS)

    Johnson, K. L.; Steinberg, L. L.

    1968-01-01

    Automated statistical and worst case computer program has been designed to perform dc and ac steady circuit analyses. The program determines the worst case circuit performance by solving circuit equations.

  1. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area of any coal mine shall be protected by suitable circuit breakers of adequate interrupting...

  2. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with devices to provide protection against under-voltage grounded phase, short circuit, and overcurrent. ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground...

  3. Framed 4-graphs: Euler tours, Gauss circuits and rotating circuits

    SciTech Connect

    Il'yutko, Denis P

    2011-09-30

    We consider connected finite 4-valent graphs with the structure of opposite edges at each vertex (framed 4-graphs). For any of such graphs there exist Euler tours, in travelling along which at each vertex we turn from an edge to a nonopposite one (rotating circuits); and at the same time, it is not true that for any such graph there exists an Euler tour passing from an edge to the opposite one at each vertex (a Gauss circuit). The main result of the work is an explicit formula connecting the adjacency matrices of the Gauss circuit and an arbitrary Euler tour. This formula immediately gives us a criterion for the existence of a Gauss circuit on a given framed 4-graph. It turns out that the results are also valid for all symmetric matrices (not just for matrices realisable by a chord diagram). Bibliography: 24 titles.

  4. Framed 4-graphs: Euler tours, Gauss circuits and rotating circuits

    NASA Astrophysics Data System (ADS)

    Il'yutko, Denis P.

    2011-09-01

    We consider connected finite 4-valent graphs with the structure of opposite edges at each vertex (framed 4-graphs). For any of such graphs there exist Euler tours, in travelling along which at each vertex we turn from an edge to a nonopposite one (rotating circuits); and at the same time, it is not true that for any such graph there exists an Euler tour passing from an edge to the opposite one at each vertex (a Gauss circuit). The main result of the work is an explicit formula connecting the adjacency matrices of the Gauss circuit and an arbitrary Euler tour. This formula immediately gives us a criterion for the existence of a Gauss circuit on a given framed 4-graph. It turns out that the results are also valid for all symmetric matrices (not just for matrices realisable by a chord diagram). Bibliography: 24 titles.

  5. Integrated circuits, and design and manufacture thereof

    SciTech Connect

    Auracher, Stefan; Pribbernow, Claus; Hils, Andreas

    2006-04-18

    A representation of a macro for an integrated circuit layout. The representation may define sub-circuit cells of a module. The module may have a predefined functionality. The sub-circuit cells may include at least one reusable circuit cell. The reusable circuit cell may be configured such that when the predefined functionality of the module is not used, the reusable circuit cell is available for re-use.

  6. Ladder supported ring bar circuit

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G. (Inventor)

    1983-01-01

    An improved slow wave circuit especially useful in backward wave oscillators includes a slow wave circuit in a waveguide. The slow wave circuit is comprised of rings disposed between and attached to respective stubs. The stubs are attached to opposing sidewalls of the waveguide. To the end that opposed, interacting magnetic fields will be established to provide a very high coupling impedance for the slow wave structure, axially orientated bars are connected between rings in alternate spaces and adjacent to the attachment points of stubs. Similarly, axial bars are connected between rings in the spaces which do not include bars and at points adjacent to the attachment of bars.

  7. Searching Circuit For A Servoloop

    NASA Technical Reports Server (NTRS)

    Sigman, E. H.

    1988-01-01

    Feedback error voltage forced into range of stability. Circuit connected in series with error-voltage line of feedback loop. When loop operates normally in stable region, searching circuit does not disturb operation, and error-voltage output of loop filter is control voltage. When servo unlocks and error-voltage output of loop filter wanders into unstable range, searching circuit forces control voltage to sweep through stable region repeatedly until lock recovered. Consists of two halves identical except polarities of some parts in each half opposite of corresponding parts in other half.

  8. Counterpulse railgun energy recovery circuit

    DOEpatents

    Honig, E.M.

    1984-09-28

    The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  9. Overpulse railgun energy recovery circuit

    DOEpatents

    Honig, E.M.

    1984-09-28

    The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  10. Midbrain circuits for defensive behaviour.

    PubMed

    Tovote, Philip; Esposito, Maria Soledad; Botta, Paolo; Chaudun, Fabrice; Fadok, Jonathan P; Markovic, Milica; Wolff, Steffen B E; Ramakrishnan, Charu; Fenno, Lief; Deisseroth, Karl; Herry, Cyril; Arber, Silvia; Lüthi, Andreas

    2016-06-01

    Survival in threatening situations depends on the selection and rapid execution of an appropriate active or passive defensive response, yet the underlying brain circuitry is not understood. Here we use circuit-based optogenetic, in vivo and in vitro electrophysiological, and neuroanatomical tracing methods to define midbrain periaqueductal grey circuits for specific defensive behaviours. We identify an inhibitory pathway from the central nucleus of the amygdala to the ventrolateral periaqueductal grey that produces freezing by disinhibition of ventrolateral periaqueductal grey excitatory outputs to pre-motor targets in the magnocellular nucleus of the medulla. In addition, we provide evidence for anatomical and functional interaction of this freezing pathway with long-range and local circuits mediating flight. Our data define the neuronal circuitry underlying the execution of freezing, an evolutionarily conserved defensive behaviour, which is expressed by many species including fish, rodents and primates. In humans, dysregulation of this 'survival circuit' has been implicated in anxiety-related disorders. PMID:27279213

  11. Noise consideration in RSFQ circuits

    NASA Astrophysics Data System (ADS)

    Kaplunenko, V.

    2002-08-01

    Recently we reported a direct time jitter measurement, obtained using a ring-like Josephson transmission line (JTL). The jitter value of 0.2 ps/ n ( n--number of junctions in JTL) was obtained for the circuit that was fabricated using the 1 kA/cm 2 Hypres process. In this paper, we report the following investigation of the noise impact on rapid single flux quantum circuits in general, and particularly on two types of clock recovery circuits. The study explains the previously obtained results and shows that a wide frequency band clock recovery unit can be made using 50-junctions and a low-yield high-temperature superconductor technology and operating at 50 K. This approach would relatively easily enable us to implement such a circuit using the packaging of Conductus' commercial products for the wireless industry, which include a cryo-cooler, low noise amplifiers, and a high-frequency interface.

  12. Leveling circuits and crustal movements

    NASA Technical Reports Server (NTRS)

    Chi, S. C.; Reilinger, R. E.; Brown, L. D.; Oliver, J. E.

    1980-01-01

    An investigation of further possible vertical crustal movements in the Western United States made with circuit microclosure analysis is presented. The San Andreas fault in Cal., the Nevada seismic zone in Nev., and the Sierra Nevada in Calif. were studied based on supposition that in areas undergoing crustal movement the misclosure for a particular circuit should have the smallest value when the circuit is formed from the most temporarily homogeneous survey data; it should have larger, predictable values when the circuit is closed with surveys conducted at other times. Leveling surveys along the San Andreas fault and the Nevada seismic zone are discussed, noting the possibility of regional tilting in the Great Basin between 1934 and 1955, and of elevation changes in the Northern Nevada Range using results of leveling surveys between Roseville, Cal. and Reno, Nev.

  13. Focal plane infrared readout circuit

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor)

    2002-01-01

    An infrared imager, such as a spectrometer, includes multiple infrared photodetectors and readout circuits for reading out signals from the photodetectors. Each readout circuit includes a buffered direct injection input circuit including a differential amplifier with active feedback provided through an injection transistor. The differential amplifier includes a pair of input transistors, a pair of cascode transistors and a current mirror load. Photocurrent from a photodetector can be injected onto an integration capacitor in the readout circuit with high injection efficiency at high speed. A high speed, low noise, wide dynamic range linear infrared multiplexer array for reading out infrared detectors with large capacitances can be achieved even when short exposure times are used. The effect of image lag can be reduced.

  14. Automated Design of Quantum Circuits

    NASA Technical Reports Server (NTRS)

    Williams, C.; Gray, G.

    1998-01-01

    In order to design a quantum circuit that performs a desired quantum computation, it is necessary to find a decomposition of the unitary matrix that represents that computation in terms of a sequence of quantum gate operations.

  15. Student Conceptions of Simple Circuits.

    ERIC Educational Resources Information Center

    Fredette, Norman; Lochhead, John

    1980-01-01

    Investigates some conceptual difficulties which college students have with regard to simple direct current circuits. The clinical interview technique was used with 57 students in a freshman level engineering course. (HM)

  16. Principles of Genetic Circuit Design

    PubMed Central

    Brophy, Jennifer A.N.; Voigt, Christopher A.

    2014-01-01

    Cells are able to navigate environments, communicate, and build complex patterns by initiating gene expression in response to specific signals. Engineers need to harness this capability to program cells to perform tasks or build chemicals and materials that match the complexity seen in nature. This review describes new tools that aid the construction of genetic circuits. We show how circuit dynamics can be influenced by the choice of regulators and changed with expression “tuning knobs.” We collate the failure modes encountered when assembling circuits, quantify their impact on performance, and review mitigation efforts. Finally, we discuss the constraints that arise from operating within a living cell. Collectively, better tools, well-characterized parts, and a comprehensive understanding of how to compose circuits are leading to a breakthrough in the ability to program living cells for advanced applications, from living therapeutics to the atomic manufacturing of functional materials. PMID:24781324

  17. Detector verifier for circuit analyzers

    NASA Technical Reports Server (NTRS)

    Pope, D. L.; Wooters, R. L.

    1980-01-01

    Economical tool checks operation of automatic circuit analyzer. Each loop is addressed directly from analyzer console by switching internal analyzer bridge to resistance equal that of connecting cable plus specified limiting test value. Procedure verifies whether detected faults in circuit under test are actually due to analyzer malfunction. Standard-length universal test cables make it possible to shift detector tool from cable to cable without resistance compensation.

  18. Reverse engineering of integrated circuits

    DOEpatents

    Chisholm, Gregory H.; Eckmann, Steven T.; Lain, Christopher M.; Veroff, Robert L.

    2003-01-01

    Software and a method therein to analyze circuits. The software comprises several tools, each of which perform particular functions in the Reverse Engineering process. The analyst, through a standard interface, directs each tool to the portion of the task to which it is most well suited, rendering previously intractable problems solvable. The tools are generally used iteratively to produce a successively more abstract picture of a circuit, about which incomplete a priori knowledge exists.

  19. Receiver Gain Modulation Circuit

    NASA Technical Reports Server (NTRS)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  20. 46 CFR 169.670 - Circuit breakers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST... Gross Tons § 169.670 Circuit breakers. Each circuit breaker must be of the manually reset type designed for— (a) Inverse time delay; (b) Instantaneous short circuit protection; and (c) Repeated opening...

  1. 46 CFR 169.670 - Circuit breakers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST... Gross Tons § 169.670 Circuit breakers. Each circuit breaker must be of the manually reset type designed for— (a) Inverse time delay; (b) Instantaneous short circuit protection; and (c) Repeated opening...

  2. 46 CFR 169.670 - Circuit breakers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST... Gross Tons § 169.670 Circuit breakers. Each circuit breaker must be of the manually reset type designed for— (a) Inverse time delay; (b) Instantaneous short circuit protection; and (c) Repeated opening...

  3. 46 CFR 169.670 - Circuit breakers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST... Gross Tons § 169.670 Circuit breakers. Each circuit breaker must be of the manually reset type designed for— (a) Inverse time delay; (b) Instantaneous short circuit protection; and (c) Repeated opening...

  4. Bypassing An Open-Circuit Power Cell

    NASA Technical Reports Server (NTRS)

    Wannemacher, Harry E.

    1994-01-01

    Collection of bypass circuits enables battery consisting series string of cells to continue to function when one of its cells fails in open-circuit (high-resistance) condition. Basic idea simply to shunt current around defective cell to prevent open circuit from turning off battery altogether. Bypass circuits dissipate little power and are nearly immune to false activation.

  5. Improved self arbitrated VLSI asynchronous circuits

    NASA Technical Reports Server (NTRS)

    Winterrowd, P.

    1991-01-01

    This paper introduces an improved method for designing the class of CMOS VLSI asynchronous sequential circuits introduced in the paper by Sterling R. Whitaker and Gary K. Maki, 'Self Arbitrated VLSI Asynchronous Circuits.' Of main interest here is the simple design by inspection rules that arise from these circuits. This paper presents a variation on these circuits which reduces the number of transistors required.

  6. Tunable circuit for tunable capacitor devices

    SciTech Connect

    Rivkina, Tatiana; Ginley, David S.

    2006-09-19

    A tunable circuit (10) for a capacitively tunable capacitor device (12) is provided. The tunable circuit (10) comprises a tunable circuit element (14) and a non-tunable dielectric element (16) coupled to the tunable circuit element (16). A tunable capacitor device (12) and a method for increasing the figure of merit in a tunable capacitor device (12) are also provided.

  7. Difference-Equation/Flow-Graph Circuit Analysis

    NASA Technical Reports Server (NTRS)

    Mcvey, I. M.

    1988-01-01

    Numerical technique enables rapid, approximate analyses of electronic circuits containing linear and nonlinear elements. Practiced in variety of computer languages on large and small computers; for circuits simple enough, programmable hand calculators used. Although some combinations of circuit elements make numerical solutions diverge, enables quick identification of divergence and correction of circuit models to make solutions converge.

  8. Multi-Layer E-Textile Circuits

    NASA Technical Reports Server (NTRS)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  9. Digital first order hold circuit

    NASA Technical Reports Server (NTRS)

    Chan, Fred N. (Inventor); Wensley, Gerald J. (Inventor)

    1989-01-01

    There is provided a digitally controlled first order hold circuit and waveform synthesizer for digitally controlling the representation of a function over an approximation interval. In accordance with the operation of the invention, the first order hold circuit and waveform generator receives a digital data input signal which contains initial condition data, up/down data, and slope data for the approximation interval. The initial condition data is loaded into an up/down counter which is incremented using counting data at a rate depending on the value of the slope data and in a direction depending on the value of the up-down data. In order to minimize delays arising from data acquistion, two frequency synthesizer circuits are provided such that one frequency synthesizer provides counting data while the other frequency synthesizer receives slope data. During alternating intervals, the other frequency synthesizer circuit provides counting data while the other circuit receives slope data. In addition, long length data input signals covering a plurality of approximation intervals are provided to reduce the demands on a main system central processing unit.

  10. Bioluminescent bioreporter integrated circuits (BBICs)

    NASA Astrophysics Data System (ADS)

    Simpson, Michael L.; Sayler, Gary S.; Nivens, David; Ripp, Steve; Paulus, Michael J.; Jellison, Gerald E.

    1998-07-01

    As the workhorse of the integrated circuit (IC) industry, the capabilities of CMOS have been expanded well beyond the original applications. The full spectrum of analog circuits from switched-capacitor filters to microwave circuit blocks, and from general-purpose operational amplifiers to sub- nanosecond analog timing circuits for nuclear physics experiments have been implemented in CMOS. This technology has also made in-roads into the growing area of monolithic sensors with devices such as active-pixel sensors and other electro-optical detection devices. While many of the processes used for MEMS fabrication are not compatible with the CMOS IC process, depositing a sensor material onto a previously fabricated CMOS circuit can create a very useful category of sensors. In this work we report a chemical sensor composed of bioluminescent bioreporters (genetically engineered bacteria) deposited onto a micro-luminometer fabricated in a standard CMOS IC process. The bioreporter used for this work emitted 490-nm light when exposed to toluene. This luminescence was detected by the micro- luminometer giving an indication of the concentration of toluene. Other bioluminescent bioreporters sensitive to explosives, mercury, and other organic chemicals and heavy metals have been reported. These could be incorporated (individually or in combination) with the micro-luminometer reported here to form a variety of chemical sensors.

  11. Decoupling with Random Quantum Circuits

    NASA Astrophysics Data System (ADS)

    Brown, Winton; Fawzi, Omar

    2015-12-01

    Decoupling has become a central concept in quantum information theory, with applications including proving coding theorems, randomness extraction and the study of conditions for reaching thermal equilibrium. However, our understanding of the dynamics that lead to decoupling is limited. In fact, the only families of transformations that are known to lead to decoupling are (approximate) unitary two-designs, i.e., measures over the unitary group that behave like the Haar measure as far as the first two moments are concerned. Such families include for example random quantum circuits with O( n 2) gates, where n is the number of qubits in the system under consideration. In fact, all known constructions of decoupling circuits use Ω( n 2) gates. Here, we prove that random quantum circuits with O( n log2 n) gates satisfy an essentially optimal decoupling theorem. In addition, these circuits can be implemented in depth O(log3 n). This proves that decoupling can happen in a time that scales polylogarithmically in the number of particles in the system, provided all the particles are allowed to interact. Our proof does not proceed by showing that such circuits are approximate two-designs in the usual sense, but rather we directly analyze the decoupling property.

  12. Neurotrophins and spinal circuit function

    PubMed Central

    Boyce, Vanessa S.; Mendell, Lorne M.

    2014-01-01

    Work early in the last century emphasized the stereotyped activity of spinal circuits based on studies of reflexes. However, the last several decades have focused on the plasticity of these spinal circuits. These considerations began with studies of the effects of monoamines on descending and reflex circuits. In recent years new classes of compounds called growth factors that are found in peripheral nerves and the spinal cord have been shown to affect circuit behavior in the spinal cord. In this review we will focus on the effects of neurotrophins, particularly nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), on spinal circuits. We also discuss evidence that these molecules can modify functions including nociceptive behavior, motor reflexes and stepping behavior. Since these substances and their receptors are normally present in the spinal cord, they could potentially be useful in improving function in disease states and after injury. Here we review recent findings relevant to these translational issues. PMID:24926235

  13. Normal Development of Brain Circuits

    PubMed Central

    Tau, Gregory Z; Peterson, Bradley S

    2010-01-01

    Spanning functions from the simplest reflex arc to complex cognitive processes, neural circuits have diverse functional roles. In the cerebral cortex, functional domains such as visual processing, attention, memory, and cognitive control rely on the development of distinct yet interconnected sets of anatomically distributed cortical and subcortical regions. The developmental organization of these circuits is a remarkably complex process that is influenced by genetic predispositions, environmental events, and neuroplastic responses to experiential demand that modulates connectivity and communication among neurons, within individual brain regions and circuits, and across neural pathways. Recent advances in neuroimaging and computational neurobiology, together with traditional investigational approaches such as histological studies and cellular and molecular biology, have been invaluable in improving our understanding of these developmental processes in humans in both health and illness. To contextualize the developmental origins of a wide array of neuropsychiatric illnesses, this review describes the development and maturation of neural circuits from the first synapse through critical periods of vulnerability and opportunity to the emergent capacity for cognitive and behavioral regulation, and finally the dynamic interplay across levels of circuit organization and developmental epochs. PMID:19794405

  14. Introduction to lethal circuit transformations

    NASA Astrophysics Data System (ADS)

    Fišer, Petr; Schmidt, Jan

    2015-12-01

    Logic optimization is a process that takes a logic circuit description (Boolean network) as an input and tries to refine it, to reduce its size and/or depth. An ideal optimization process should be able to devise an optimum implementation of a network in a reasonable time, given any circuit structure at the input. However, there are cases where it completely fails to produce even near-optimum solutions. Such cases are typically induced by non-standard circuit structure modifications. Surprisingly enough, such deviated structures are frequently present in standard benchmark sets too. We may only wonder whether it is an intention of the benchmarks creators, or just an unlucky coincidence. Even though synthesis tools should be primarily well suited for practical circuits, there is no guarantee that, e.g., a higher-level synthesis process will not generate such unlucky structures. Here we present examples of circuit transformations that lead to failure of most of state-of-the-art logic synthesis and optimization processes, both academic and commercial, and suggest actions to mitigate the disturbing effects.

  15. Architecture and algorithm of a circuit simulator

    NASA Astrophysics Data System (ADS)

    Marranghello, Norian; Damiani, Furio

    1990-11-01

    Software-based circuit simulators had a ten-fold speed improvement in the last 15 years. Despite this they are not fast enough to cost- effectively deal with current VLSI circuits. In this paper we describe the current status of the ABACUS circuit simulator project, which takes advantage of both a dedicated hardware to speed up circuit simulation and a new methodology, where each parallel processor behaves like a circuit element.

  16. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Electric equipment and circuits; overload...

  17. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Electric equipment and circuits; overload...

  18. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Electric equipment and circuits; overload...

  19. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload...

  20. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Electric equipment and circuits; overload...

  1. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable...

  2. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train...

  3. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... devices to provide protection against under voltage, grounded phase, short circuit and overcurrent. High... 30 Mineral Resources 1 2011-07-01 2011-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers....

  4. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Short circuit protection; ratings and settings... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers. Circuit breakers providing short circuit protection for trailing cables shall be set so as not to exceed...

  5. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; ratings and settings... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers. Circuit breakers providing short circuit protection for trailing cables shall be set so as not to exceed...

  6. Nuclear sensor signal processing circuit

    DOEpatents

    Kallenbach, Gene A.; Noda, Frank T.; Mitchell, Dean J.; Etzkin, Joshua L.

    2007-02-20

    An apparatus and method are disclosed for a compact and temperature-insensitive nuclear sensor that can be calibrated with a non-hazardous radioactive sample. The nuclear sensor includes a gamma ray sensor that generates tail pulses from radioactive samples. An analog conditioning circuit conditions the tail-pulse signals from the gamma ray sensor, and a tail-pulse simulator circuit generates a plurality of simulated tail-pulse signals. A computer system processes the tail pulses from the gamma ray sensor and the simulated tail pulses from the tail-pulse simulator circuit. The nuclear sensor is calibrated under the control of the computer. The offset is adjusted using the simulated tail pulses. Since the offset is set to zero or near zero, the sensor gain can be adjusted with a non-hazardous radioactive source such as, for example, naturally occurring radiation and potassium chloride.

  7. Design automation for integrated circuits

    NASA Astrophysics Data System (ADS)

    Newell, S. B.; de Geus, A. J.; Rohrer, R. A.

    1983-04-01

    Consideration is given to the development status of the use of computers in automated integrated circuit design methods, which promise the minimization of both design time and design error incidence. Integrated circuit design encompasses two major tasks: error specification, in which the goal is a logic diagram that accurately represents the desired electronic function, and physical specification, in which the goal is an exact description of the physical locations of all circuit elements and their interconnections on the chip. Design automation not only saves money by reducing design and fabrication time, but also helps the community of systems and logic designers to work more innovatively. Attention is given to established design automation methodologies, programmable logic arrays, and design shortcuts.

  8. Riding the circuit for IRP

    SciTech Connect

    Mashaw, R.

    1996-09-01

    In its original usage, the term {open_quotes}circuit rider{close_quotes} described a minister supported by several congregations, who rode from rural church to rural church spreading religion. Today, thanks to a grant from the Department of Energy, there`s a new kind of circuit rider at work in small communities and rural areas, spreading the gospel of integrated resource planning. The concept of the circuit rider was advanced in 1994 by a coalition of associations, private businesses and government agencies, including the American Public Power Association, the National Rural Electric Cooperative Association, the federal power marketing agencies and the National Renewable Energy Laboratory. The group proposed to DOE the creation of a program for the advancement of integrated resource planning (IRP) in public power, designed to extend the resources and capabilities of publicly and cooperatively owned utilities in IRP by offering a several types of assistance, including training, direct consultation and publications.

  9. Counterpulse railgun energy recovery circuit

    SciTech Connect

    Honig, E.M.

    1986-02-25

    This patent describes a counterpulse railgun energy recovery circuit for propelling a projectile along a railgun the counterpulse railgun energy recovery circuit consists of: a railgun having an effective inductance; a source inductor initially charged to an initial current; current means for initially charging the source inductor to the initial current; first current-zero type switching means; second current-zero type switching; third current-zero type switching; muzzle current-zero type switching means; transfer capacitor, the transfer capacitor is for cooperating with the first, second, third, and muzzle current-zero type switching means for providing a resonant circuit for transferring current from the source inductor to the effective inductance of the railgun during the propelling of a projectile along the railgun and for returning current from the effective inductance of the railgun to the source inductance after the projectile has exited the railgun.

  10. Additive Manufacturing of Hybrid Circuits

    NASA Astrophysics Data System (ADS)

    Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David; Hirschfeld, Deidre; Hall, Aaron C.; Bell, Nelson S.

    2016-07-01

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. Finally, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  11. Vertically Integrated Circuits at Fermilab

    SciTech Connect

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  12. Pulsed thyristor trigger control circuit

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A trigger control circuit is provided for producing firing pulses for the thyristor of a thyristor control system such as a power factor controller. The control circuit overcomes thyristor triggering problems involved with the current lag associated with controlling inductive loads and utilizes a phase difference signal, already present in the power factor controller, in deriving a signal for inhibiting generation of a firing pulse until no load current is flowing from the preceding half cycle and thereby ensuring that the thyristor is triggered on during each half cycle.

  13. Circuit breaker lock out assembly

    DOEpatents

    Gordy, Wade T.

    1984-01-01

    A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly "S" shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

  14. Programming languages for circuit design.

    PubMed

    Pedersen, Michael; Yordanov, Boyan

    2015-01-01

    This chapter provides an overview of a programming language for Genetic Engineering of Cells (GEC). A GEC program specifies a genetic circuit at a high level of abstraction through constraints on otherwise unspecified DNA parts. The GEC compiler then selects parts which satisfy the constraints from a given parts database. GEC further provides more conventional programming language constructs for abstraction, e.g., through modularity. The GEC language and compiler is available through a Web tool which also provides functionality, e.g., for simulation of designed circuits. PMID:25487094

  15. Electrochemical planarization for microelectronic circuits

    SciTech Connect

    Contolini, R.J.; Mayer, S.T.; Bernhardt, A.F.

    1993-03-25

    The need for flatter and smoother surfaces (planarization) in microelectronic circuits increases as the number of metal levels in ultra large scale integrated (ULSI) circuits increases. At Lawrence Livermore National Laboratory, the authors have developed an electrochemical planarization process that fills vias and trenches with metal (without voids) and subsequently planarizes the surface. Use is made of plasma-enhanced chemical vapor deposition (PECVD) of SiO[sub 2] for the dielectric layers and electroplated copper for the metalization. This report describes the advantages of this process over existing techniques, possibilities for collaboration, and previous technology transfer.

  16. Electrochemical planarization for microelectronic circuits

    NASA Astrophysics Data System (ADS)

    Contolini, R. J.; Mayer, S. T.; Bernhardt, A. F.

    1993-03-01

    The need for flatter and smoother surfaces (planarization) in microelectronic circuits increases as the number of metal levels in ultra large scale integrated (ULSI) circuits increases. At Lawrence Livermore National Laboratory, the authors have developed an electrochemical planarization process that fills vias and trenches with metal (without voids) and subsequently planarizes the surface. Use is made of plasma-enhanced chemical vapor deposition (PECVD) of SiO2 for the dielectric layers and electroplated copper for the metalization. This report describes the advantages of this process over existing techniques, possibilities for collaboration, and previous technology transfer.

  17. Logic synthesis of cascade circuits

    NASA Astrophysics Data System (ADS)

    Zakrevskii, A. D.

    The work reviews aspects of the logic design of cascade circuits, particularly programmable logic matrices. Effective methods for solving various problems of the analysis and synthesis of these devices are examined; these methods are based on a matrix representation of the structure of these devices, and a vector-matrix interpretation of certain aspects of Boolean algebra. Particular consideration is given to the theory of elementary matrix circuits, methods for the minimization of Boolean functions, the synthesis of programmable logic matrices, multilevel combinational networks, and the development of automata with memory.

  18. Subminiature deflection circuit operates integrated sweep circuits in TV camera

    NASA Technical Reports Server (NTRS)

    Schaff, F. L.

    1967-01-01

    Small magnetic sweep deflection circuits operate a hand-held lunar television camera. They convert timing signals from the synchronizer into waveforms that provide a raster on the vidicon target. Raster size remains constant and linear during wide voltage and temperature fluctuations.

  19. Fast Langmuir probe sweeping circuit

    SciTech Connect

    Milnes, K.A.; Ehlers, K.W.; Leung, K.N.; Owren, H.M.; Williams, M.D.

    1980-06-01

    An inexpensive, simple, and fast Langmuir probe sweeping circuit is presented. This sweeper completes a probe trace in 1.4 ms and has a maximum probe current capability of 5 A. It is suitable for pulsemode plasma operation with density greater than 10/sup 12/ ions/cm/sup 3/.

  20. Advanced Imaging of Elementary Circuits

    ERIC Educational Resources Information Center

    Baird, William H.; Richards, Caleb; Godbole, Pranav

    2012-01-01

    Students commonly find the second semester of introductory physics to be more challenging than the first, probably due to the mechanical intuition we acquire just by moving around. For most students, there is no similar comfort with electricity or magnetism. In an effort to combat this confusion, we decided to examine simple electric circuits with…

  1. Multiplier Architecture for Coding Circuits

    NASA Technical Reports Server (NTRS)

    Wang, C. C.; Truong, T. K.; Shao, H. M.; Deutsch, L. J.

    1986-01-01

    Multipliers based on new algorithm for Galois-field (GF) arithmetic regular and expandable. Pipeline structures used for computing both multiplications and inverses. Designs suitable for implementation in very-large-scale integrated (VLSI) circuits. This general type of inverter and multiplier architecture especially useful in performing finite-field arithmetic of Reed-Solomon error-correcting codes and of some cryptographic algorithms.

  2. No-warp potted circuits

    NASA Technical Reports Server (NTRS)

    Robinson, W. W.

    1979-01-01

    Sponge inserts compensate for potting-compound expansion and relieve thermal stresses on circuit boards. Technique quality of production runs on PC boards intended for applications in environments less severe than those for aerospace equipment. Pads reduce weight of modules because they weigh far less than potting compound they displace.

  3. Low-frequency attenuator circuit

    NASA Technical Reports Server (NTRS)

    Cash, W. H., Jr.; Polyhemus, J. T.

    1979-01-01

    Circuit uses only single operational amplifier and few passive components to remove background noise from miniature "wristwatch" pulse detector. It can be applied to other systems where background noise is slowly varying, such as ultrasonics, strain-gage sensors, and accelerometers.

  4. Integrated Circuit Stellar Magnitude Simulator

    ERIC Educational Resources Information Center

    Blackburn, James A.

    1978-01-01

    Describes an electronic circuit which can be used to demonstrate the stellar magnitude scale. Six rectangular light-emitting diodes with independently adjustable duty cycles represent stars of magnitudes 1 through 6. Experimentally verifies the logarithmic response of the eye. (Author/GA)

  5. MOS integrated circuit fault modeling

    NASA Technical Reports Server (NTRS)

    Sievers, M.

    1985-01-01

    Three digital simulation techniques for MOS integrated circuit faults were examined. These techniques embody a hierarchy of complexity bracketing the range of simulation levels. The digital approaches are: transistor-level, connector-switch-attenuator level, and gate level. The advantages and disadvantages are discussed. Failure characteristics are also described.

  6. Branch Mode Selection during Early Lung Development

    PubMed Central

    Menshykau, Denis; Kraemer, Conradin; Iber, Dagmar

    2012-01-01

    Many organs of higher organisms, such as the vascular system, lung, kidney, pancreas, liver and glands, are heavily branched structures. The branching process during lung development has been studied in great detail and is remarkably stereotyped. The branched tree is generated by the sequential, non-random use of three geometrically simple modes of branching (domain branching, planar and orthogonal bifurcation). While many regulatory components and local interactions have been defined an integrated understanding of the regulatory network that controls the branching process is lacking. We have developed a deterministic, spatio-temporal differential-equation based model of the core signaling network that governs lung branching morphogenesis. The model focuses on the two key signaling factors that have been identified in experiments, fibroblast growth factor (FGF10) and sonic hedgehog (SHH) as well as the SHH receptor patched (Ptc). We show that the reported biochemical interactions give rise to a Schnakenberg-type Turing patterning mechanisms that allows us to reproduce experimental observations in wildtype and mutant mice. The kinetic parameters as well as the domain shape are based on experimental data where available. The developed model is robust to small absolute and large relative changes in the parameter values. At the same time there is a strong regulatory potential in that the switching between branching modes can be achieved by targeted changes in the parameter values. We note that the sequence of different branching events may also be the result of different growth speeds: fast growth triggers lateral branching while slow growth favours bifurcations in our model. We conclude that the FGF10-SHH-Ptc1 module is sufficient to generate pattern that correspond to the observed branching modes. PMID:22359491

  7. Branch mode selection during early lung development.

    PubMed

    Menshykau, Denis; Kraemer, Conradin; Iber, Dagmar

    2012-01-01

    Many organs of higher organisms, such as the vascular system, lung, kidney, pancreas, liver and glands, are heavily branched structures. The branching process during lung development has been studied in great detail and is remarkably stereotyped. The branched tree is generated by the sequential, non-random use of three geometrically simple modes of branching (domain branching, planar and orthogonal bifurcation). While many regulatory components and local interactions have been defined an integrated understanding of the regulatory network that controls the branching process is lacking. We have developed a deterministic, spatio-temporal differential-equation based model of the core signaling network that governs lung branching morphogenesis. The model focuses on the two key signaling factors that have been identified in experiments, fibroblast growth factor (FGF10) and sonic hedgehog (SHH) as well as the SHH receptor patched (Ptc). We show that the reported biochemical interactions give rise to a Schnakenberg-type Turing patterning mechanisms that allows us to reproduce experimental observations in wildtype and mutant mice. The kinetic parameters as well as the domain shape are based on experimental data where available. The developed model is robust to small absolute and large relative changes in the parameter values. At the same time there is a strong regulatory potential in that the switching between branching modes can be achieved by targeted changes in the parameter values. We note that the sequence of different branching events may also be the result of different growth speeds: fast growth triggers lateral branching while slow growth favours bifurcations in our model. We conclude that the FGF10-SHH-Ptc1 module is sufficient to generate pattern that correspond to the observed branching modes. PMID:22359491

  8. Automated manual transmission mode selection controller

    DOEpatents

    Lawrie, Robert E.

    1999-11-09

    A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

  9. Fabric circuits and method of manufacturing fabric circuits

    NASA Technical Reports Server (NTRS)

    Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)

    2011-01-01

    A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.

  10. Analog Nonvolatile Computer Memory Circuits

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd

    2007-01-01

    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  11. Terahertz backward wave oscillator circuits

    NASA Astrophysics Data System (ADS)

    Oviedo Vela, Guillermo Antonio

    This work focuses on increasing the electric field mode-electron beam interaction in terahertz backward-wave oscillators through increasing the interaction impedance of the slow wave circuit. In a backward wave oscillator (BWO) or a traveling wave tube (TWT), the electric field traveling in the waveguide interacts with an electron beam grazing or piercing the electric field of a slow wave circuit and transfers energy from the beam to the circuit mode. The mechanism of this interaction is analyzed and the traditional model is adapted to provide one that is scalable to terahertz frequencies. The efficiency of the BWO can be enhanced by improving the interaction between the beam and the circuit modes, utilizing beam sources with greater current densities and using larger magnetic fields. This work presents the results on the modeling, fabrication and performance of the mode-piercing and mode-grazing slow wave circuits studied. Meandering folded waveguides and interdigital lines were modeled to evaluate their interaction impedance and electron beam requirements at terahertz frequencies. The models were verified against published results. Because of their low interaction impedance, terahertz meandering waveguides would need to be excited with large current density electron beams which in turn would require large magnets for their control. Interdigital lines were found to be the slow-wave circuit of choice in this work because their high interaction impedance and their ability to operate with low voltage, and low current density electron beams. Finite element numerical calculations were used to design, optimize and scale a terahertz free interdigital line (FIDL) circuit. The designed free interdigital line was fabricated using microfabrication technologies. Characterization of a free interdigital line (FIDL) circuit was performed in a tube body with a dispenser cathode and a three-anode Pierce gun. The FIDL measured output was compared with the calculated result and its

  12. Driver circuit for solid state light sources

    DOEpatents

    Palmer, Fred; Denvir, Kerry; Allen, Steven

    2016-02-16

    A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

  13. 30 CFR 56.6403 - Branch circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits,...

  14. 30 CFR 56.6403 - Branch circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits,...

  15. 30 CFR 56.6403 - Branch circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits,...

  16. 30 CFR 56.6403 - Branch circuits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits,...

  17. 30 CFR 56.6403 - Branch circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits,...

  18. Auxiliary circuit enables automatic monitoring of EKG'S

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Auxiliary circuits allow direct, automatic monitoring of electrocardiograms by digital computers. One noiseless square-wave output signal for each trigger pulse from an electrocardiogram preamplifier is produced. The circuit also permits automatic processing of cardiovascular data from analog tapes.

  19. Plug-in integrated/hybrid circuit

    NASA Technical Reports Server (NTRS)

    Stringer, E. J.

    1974-01-01

    Hybrid circuitry can be installed into standard round bayonet connectors, to eliminate wiring from connector to circuit. Circuits can be connected directly into either section of connector pair, eliminating need for hard wiring to that section.

  20. Post regulation circuit with energy storage

    DOEpatents

    Ball, Don G.; Birx, Daniel L.; Cook, Edward G.

    1992-01-01

    A charge regulation circuit provides regulation of an unregulated voltage supply and provides energy storage. The charge regulation circuit according to the present invention provides energy storage without unnecessary dissipation of energy through a resistor as in prior art approaches.

  1. Performance optimization of digital VLSI circuits

    SciTech Connect

    Marple, D.P.

    1987-01-01

    Designers of digital VLSI circuits have virtually no computer tools available for the optimization of circuit performance. Instead, a designer relies extensively on circuit-analysis tools, such as circuit simulation (SPICE) and/or critical-delay-path analysis. A circuit-analysis approach to digital design is very labor-intensive and seldom produces a circuit with optimum area/delay or power/delay trade off. The goal of this research is to provide a synthesis approach to the design of digital circuits by finding the sizes of transistors that optimize circuits by finding the sizes of transistors that optimize circuit performance (delay, area, power). Solutions are found that are optimum for all possible delay paths of a given circuit and not for just a single path. The approach of this research is to formulate the problem of area/delay or power/delay optimization as a nonlinear program. Conditions for optimality are then established using graph theory and Kuhn-Tucker conditions. Finally, the use of augmented-Lagrangian and projected-Lagrangian algorithms are reviewed for the solution of the nonlinear programs. Two computer programs, PLATO and COP, were developed by the author to optimize CMOS PLA's (PLATO) and general CMOS circuits (COP). These tools provably find the globally optimum transistor sizes for a given circuit. Results are presented for PLA's and small- to medium-sized cells.

  2. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  3. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  4. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting circuit. (c) Detonator leg wires shall be shunted until connected into the blasting circuit. (d) Blasting cables shall be— (1) Well...

  5. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  6. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made by different manufacturers shall not be combined in the same blasting circuit. (c) Detonator leg wires shall be shunted until connected into the blasting circuit. (d) Blasting cables shall be— (1) Well...

  7. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2012-10-01 2012-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  8. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  9. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  10. 49 CFR 236.726 - Circuit, track.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  11. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ... 49 Transportation 4 2013-10-01 2013-10-01 false Circuit, control. 236.721 Section 236.721 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD...

  12. The dc power circuits: A compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A compilation of reports concerning power circuits is presented for the dissemination of aerospace information to the general public as part of the NASA Technology Utilization Program. The descriptions for the electronic circuits are grouped as follows: dc power supplies, power converters, current-voltage power supply regulators, overload protection circuits, and dc constant current power supplies.

  13. LARC-SI Flatwire Twin Conduction Circuits

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Eight 2-line, L-shaped gold flex circuits have been imprinted on 1-mil LARC-SI. Each circuit was embedded in a space-applications trapezoidal truss made of carbon fiber reinforced resin composite (with protruding ends) to facilitate electrical connection of electronic devices mounted on the truss. LARC-SI is an advanced polymer highly suitable for multi layered electrical circuits.

  14. New Logic Circuit with DC Parametric Excitation

    NASA Astrophysics Data System (ADS)

    Sugahara, Masanori; Kaneda, Hisayoshi

    1982-12-01

    It is shown that dc parametric excitation is possible in a circuit named JUDO, which is composed of two resistively-connected Josephson junctions. Simulation study proves that the circuit has large gain and properties suitable for the construction of small, high-speed logic circuits.

  15. Overvoltage control circuit for a reserve battery

    SciTech Connect

    Eppley, W.J.; Pertuch, W.T.; Tierney, B.C.

    1989-09-26

    This patent describes a selectively activatable reserve battery overvoltage control circuit. It comprises: a current limiting resistor; a thermal-lag circuit interrupter connected in series with the resistor; and circuit means connecting the series connection of the resistor and the interrupter across the reserve battery.

  16. 49 CFR 236.719 - Circuit, acknowledgment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, acknowledgment. 236.719 Section 236.719 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, acknowledgment. A circuit consisting of wire or other conducting material installed between...

  17. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing...

  18. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing...

  19. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Control circuits. 234.203 Section 234.203... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that affect the safe operation of a highway-rail grade crossing...

  20. Electronic test and calibration circuits, a compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A wide variety of simple test calibration circuits are compiled for the engineer and laboratory technician. The majority of circuits were found inexpensive to assemble. Testing electronic devices and components, instrument and system test, calibration and reference circuits, and simple test procedures are presented.

  1. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Blasting circuits. 75.1323 Section 75.1323 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected...

  2. 30 CFR 75.1323 - Blasting circuits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Blasting circuits. 75.1323 Section 75.1323 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected...

  3. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Control circuits. 234.203 Section 234.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that...

  4. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  5. 49 CFR 236.721 - Circuit, control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  6. 49 CFR 234.203 - Control circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Control circuits. 234.203 Section 234.203 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., Inspection, and Testing Maintenance Standards § 234.203 Control circuits. All control circuits that...

  7. Removing Bonded Integrated Circuits From Boards

    NASA Technical Reports Server (NTRS)

    Rice, John T.

    1989-01-01

    Small resistance heater makes it easier, faster, and cheaper to remove integrated circuit from hybrid-circuit board, package, or other substrate for rework. Heater, located directly in polymeric bond interface or on substrate under integrated-circuit chip, energized when necessary to remove chip. Heat generated softens adhesive or solder that bonds chip to substrate. Chip then lifted easily from substrate.

  8. Simple photometer circuits using modular electronic components

    NASA Technical Reports Server (NTRS)

    Wampler, J. E.

    1975-01-01

    Operational and peak holding amplifiers are discussed as useful circuits for bioluminescence assays. Circuit diagrams are provided. While analog methods can give a good integration on short time scales, digital methods were found best for long term integration in bioluminescence assays. Power supplies, a general photometer circuit with ratio capability, and variations in the basic photometer design are also considered.

  9. Ionization tube simmer current circuit

    DOEpatents

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  10. Ionization tube simmer current circuit

    DOEpatents

    Steinkraus, R.F. Jr.

    1994-12-13

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  11. Pattern Transformation with DNA Circuits

    PubMed Central

    Chirieleison, Steven M.; Allen, Peter B.; Simpson, Zack B.; Ellington, Andrew D.; Chen, Xi

    2014-01-01

    Readily programmable chemical networks are important tools as the scope of chemistry expands from individual molecules to larger molecular systems. While many complex systems have been constructed using conventional organic and inorganic chemistry, the programmability of biological molecules such as nucleic acids allows for precise, high-throughput, and automated design, as well as simple, rapid, and robust implementation. Here we show that systematic and quantitative control over the diffusivity and reactivity of DNA molecules yields highly programmable chemical reaction networks (CRNs) that execute at the macroscale. In particular, we design and implement non-enzymatic DNA circuits capable of performing pattern transformation algorithms such as edge detection. We also show that it is possible to fine-tune and multiplex such circuits. We believe these strategies will provide programmable platforms for prototyping CRNs, for discovering bottom-up construction principles, and for generating patterns in materials. PMID:24256862

  12. Planar Multilayer Circuit Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Minev, Z. K.; Serniak, K.; Pop, I. M.; Leghtas, Z.; Sliwa, K.; Hatridge, M.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2016-04-01

    Experimental quantum information processing with superconducting circuits is rapidly advancing, driven by innovation in two classes of devices, one involving planar microfabricated (2D) resonators, and the other involving machined three-dimensional (3D) cavities. We demonstrate that circuit quantum electrodynamics can be implemented in a multilayer superconducting structure that combines 2D and 3D advantages. We employ standard microfabrication techniques to pattern each layer, and rely on a vacuum gap between the layers to store the electromagnetic energy. Planar qubits are lithographically defined as an aperture in a conducting boundary of the resonators. We demonstrate the aperture concept by implementing an integrated, two-cavity-mode, one-transmon-qubit system.

  13. Overpulse railgun energy recovery circuit

    SciTech Connect

    Honig, E.M.

    1989-12-12

    This patent describes an overpulse railgun energy recovery circuit for propelling a projectile along a railgun. The overpulse rail gun energy recovery circuit comprising: a railgun having an effective inductance, the railgun having a breach end, a pair of parallel rails, and a muzzle end; source inductor for storing current connected across the pair of parallel rails of the railgun at the breech end thereof; means for initially charging the source inductor to an initial current for storage; switching means connected across the source inductor with a closed position for shorting across the source inductor and an open position for enabling current flow into the effective inductance of the breech end towards the muzzle end of the railgun; a muzzle switch connected across the pair of parallel rails of the railgun at the muzzle end thereof; and transfer capacitive means.

  14. Delta connected resonant snubber circuit

    DOEpatents

    Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.

    1998-01-20

    A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.

  15. Delta connected resonant snubber circuit

    DOEpatents

    Lai, Jih-Sheng; Peng, Fang Zheng; Young, Sr., Robert W.; Ott, Jr., George W.

    1998-01-01

    A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

  16. Delay locked loop integrated circuit.

    SciTech Connect

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  17. Monolithic readout circuits for RHIC

    SciTech Connect

    O`Connor, P.; Harder, J.

    1991-12-31

    Several CMOS ASICs have been developed for a proposed RHIC experiment. This paper discusses why ASIC implementation was chosen for certain functions, circuit specifications and the design techniques used to meet them, and results of simulations and early prototypes. By working closely together from an early stage in the planning process, in-house ASIC designers and detector and data acquisition experimenters can achieve optimal use of this important technology.

  18. Photoconductive circuit element pulse generator

    DOEpatents

    Rauscher, Christen

    1989-01-01

    A pulse generator for characterizing semiconductor devices at millimeter wavelength frequencies where a photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test.

  19. Counterpulse railgun energy recovery circuit

    DOEpatents

    Honig, Emanuel M.

    1986-01-01

    In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  20. Overpulse railgun energy recovery circuit

    DOEpatents

    Honig, Emanuel M.

    1989-01-01

    In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  1. Digital model of a vacuum circuit breaker for the analysis of switching waveforms in electrical circuits

    NASA Astrophysics Data System (ADS)

    Budzisz, Joanna; Wróblewski, Zbigniew

    2016-03-01

    The article presents a method of modelling a vaccum circuit breaker in the ATP/EMTP package, the results of the verification of the correctness of the developed digital circuit breaker model operation and its practical usefulness for analysis of overvoltages and overcurrents occurring in commutated capacitive electrical circuits and also examples of digital simulations of overvoltages and overcurrents in selected electrical circuits.

  2. Electrical circuit for data reduction

    SciTech Connect

    Kronberg, J.W.

    1991-12-31

    This invention is comprised of an electrical circuit for determining characteristic voltages, such as maximum, minimum, average and root mean squared voltages, of a time-varying electrical signal. The circuit comprises a positive and a negative peak detector that feed the positive and negative voltage peaks detected in each of a series of time intervals into a solid-state multiplexer controlled by a process controller. The time intervals are generated by the process controller in combination with a clocking, circuit. The multiplexer applies the positive and negative peak voltages to a set of four capacitors, apply the positive peak to one capacitor during one interval and then the negative peak to that capacitor in a subsequent interval so that each capacitor is alternatingly accumulating a positive peak then a negative peak to obviate the need for resetting each capacitor. After the positive peak voltage is applied to one capacitor, the connection is switched during the next interval for reading the negative peak voltage, then switched again for applying, a negative peak voltage, then switched once more for reading the negative peak voltage, the multiplexer serving, as a solid state commutator for switching the electrical connection. Alternatively, peak maximum and minimum voltage detectors may be replaced with circuitry designed to obtain the additional characteristic voltages desired in each interval.

  3. CONTROL AND FAULT DETECTOR CIRCUIT

    DOEpatents

    Winningstad, C.N.

    1958-04-01

    A power control and fault detectcr circuit for a radiofrequency system is described. The operation of the circuit controls the power output of a radio- frequency power supply to automatically start the flow of energizing power to the radio-frequency power supply and to gradually increase the power to a predetermined level which is below the point where destruction occurs upon the happening of a fault. If the radio-frequency power supply output fails to increase during such period, the control does not further increase the power. On the other hand, if the output of the radio-frequency power supply properly increases, then the control continues to increase the power to a maximum value. After the maximumn value of radio-frequency output has been achieved. the control is responsive to a ''fault,'' such as a short circuit in the radio-frequency system being driven, so that the flow of power is interrupted for an interval before the cycle is repeated.

  4. Additive manufacturing of hybrid circuits

    DOE PAGESBeta

    Bell, Nelson S.; Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David M.; Hirschfeld, Deidre; Hall, Aaron Christopher

    2016-03-26

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects.more » Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. As a result, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.« less

  5. The global electrical circuit: A review

    NASA Astrophysics Data System (ADS)

    Williams, Earle R.

    2009-02-01

    Research topics on the global electrical circuit are addressed that have received attention in recent years. These topics include the diurnal variation of the global circuit, surface measurements of electric field at high latitude, the annual variation, the semiannual variation, the role of lightning as a source for the global circuit, the electrical contribution of mesoscale convective systems, the possible effect of thunderstorms on the E and F regions of the ionosphere, the evidence for a global circuit impact from nuclear weapons tests, the controversy over long-term variations, the response to climate change, and finally the impact of the global circuit on climate.

  6. Method of determining the open circuit voltage of a battery in a closed circuit

    DOEpatents

    Brown, William E.

    1980-01-01

    The open circuit voltage of a battery which is connected in a closed circuit is determined without breaking the circuit or causing voltage upsets therein. The closed circuit voltage across the battery and the current flowing through it are determined under normal load and then a fractional change is made in the load and the new current and voltage values determined. The open circuit voltage is then calculated, according to known principles, from the two sets of values.

  7. Method and Circuit for Injecting a Precise Amount of Charge onto a Circuit Node

    NASA Technical Reports Server (NTRS)

    Hancock, Bruce R. (Inventor)

    2016-01-01

    A method and circuit for injecting charge into a circuit node, comprising (a) resetting a capacitor's voltage through a first transistor; (b) after the resetting, pre-charging the capacitor through the first transistor; and (c) after the pre-charging, further charging the capacitor through a second transistor, wherein the second transistor is connected between the capacitor and a circuit node, and the further charging draws charge through the second transistor from the circuit node, thereby injecting charge into the circuit node.

  8. Faster Evolution of More Multifunctional Logic Circuits

    NASA Technical Reports Server (NTRS)

    Stoica, Adrian; Zebulum, Ricardo

    2005-01-01

    A modification in a method of automated evolutionary synthesis of voltage-controlled multifunctional logic circuits makes it possible to synthesize more circuits in less time. Prior to the modification, the computations for synthesizing a four-function logic circuit by this method took about 10 hours. Using the method as modified, it is possible to synthesize a six-function circuit in less than half an hour. The concepts of automated evolutionary synthesis and voltage-controlled multifunctional logic circuits were described in a number of prior NASA Tech Briefs articles. To recapitulate: A circuit is designed to perform one of several different logic functions, depending on the value of an applied control voltage. The circuit design is synthesized following an automated evolutionary approach that is so named because it is modeled partly after the repetitive trial-and-error process of biological evolution. In this process, random populations of integer strings that encode electronic circuits play a role analogous to that of chromosomes. An evolved circuit is tested by computational simulation (prior to testing in real hardware to verify a final design). Then, in a fitness-evaluation step, responses of the circuit are compared with specifications of target responses and circuits are ranked according to how close they come to satisfying specifications. The results of the evaluation provide guidance for refining designs through further iteration.

  9. Auto-programmable impulse neural circuits

    NASA Technical Reports Server (NTRS)

    Watula, D.; Meador, J.

    1990-01-01

    Impulse neural networks use pulse trains to communicate neuron activation levels. Impulse neural circuits emulate natural neurons at a more detailed level than that typically employed by contemporary neural network implementation methods. An impulse neural circuit which realizes short term memory dynamics is presented. The operation of that circuit is then characterized in terms of pulse frequency modulated signals. Both fixed and programmable synapse circuits for realizing long term memory are also described. The implementation of a simple and useful unsupervised learning law is then presented. The implementation of a differential Hebbian learning rule for a specific mean-frequency signal interpretation is shown to have a straightforward implementation using digital combinational logic with a variation of a previously developed programmable synapse circuit. This circuit is expected to be exploited for simple and straightforward implementation of future auto-adaptive neural circuits.

  10. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection only... 46 Shipping 1 2012-10-01 2012-10-01 false Overcurrent protection and switched circuits....

  11. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection only... 46 Shipping 1 2010-10-01 2010-10-01 false Overcurrent protection and switched circuits....

  12. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection only... 46 Shipping 1 2013-10-01 2013-10-01 false Overcurrent protection and switched circuits....

  13. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection only... 46 Shipping 1 2014-10-01 2014-10-01 false Overcurrent protection and switched circuits....

  14. 46 CFR 28.365 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent device in a steering system power and control circuit must provide short circuit protection only... carrying capacity by a circuit breaker or fuse at the connection to the switchboard or distribution...

  15. Inductive storage pulse circuit device

    DOEpatents

    Parsons, William M.; Honig, Emanuel M.

    1984-01-01

    Inductive storage pulse circuit device which is capable of delivering a series of electrical pulses to a load in a sequential manner. Silicon controlled rectifiers as well as spark gap switches can be utilized in accordance with the present invention. A commutation switching array is utilized to produce a reverse current to turn-off the main opening switch. A commutation capacitor produces the reverse current and is initially charged to a predetermined voltage and subsequently charged in alternating directions by the inductive storage current.

  16. Circuit for Driving Piezoelectric Transducers

    NASA Technical Reports Server (NTRS)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  17. Circuit considerations for repetitive railguns

    SciTech Connect

    Honih, E.M.

    1986-01-01

    Railgun electromagnetic launchers have significant military and scientific potential. They provide direct conversion of electrical energy to projectile kinetic energy, and they offer the hope of achieving projectile velocities greatly exceeding the limits of conventional guns. With over 10 km/sec already demonstrated, railguns are attracting attention for tactical and strategic weapons systems and for scientific equation-of-state research. The full utilization of railguns will require significant improvements in every aspect of system design - projectile, barrel, and power source - to achieve operation on a large scale. This paper will review fundamental aspects of railguns, with emphasis on circuit considerations and repetitive operation.

  18. Polysilicon photoconductor for integrated circuits

    DOEpatents

    Hammond, Robert B.; Bowman, Douglas R.

    1989-01-01

    A photoconductive element of polycrystalline silicon is provided with intrinsic response time which does not limit overall circuit response. An undoped polycrystalline silicon layer is deposited by LPCVD to a selected thickness on silicon dioxide. The deposited polycrystalline silicon is then annealed at a selected temperature and for a time effective to obtain crystal sizes effective to produce an enhanced current output. The annealed polycrystalline layer is subsequently exposed and damaged by ion implantation to a damage factor effective to obtain a fast photoconductive response.

  19. Polysilicon photoconductor for integrated circuits

    DOEpatents

    Hammond, Robert B.; Bowman, Douglas R.

    1990-01-01

    A photoconductive element of polycrystalline silicon is provided with intrinsic response time which does not limit overall circuit response. An undoped polycrystalline silicon layer is deposited by LPCVD to a selected thickness on silicon dioxide. The deposited polycrystalline silicon is then annealed at a selected temperature and for a time effective to obtain crystal sizes effective to produce an enhanced current output. The annealed polycrystalline layer is subsequently exposed and damaged by ion implantation to a damage factor effective to obtain a fast photoconductive response.

  20. Polysilicon photoconductor for integrated circuits

    DOEpatents

    Hammond, R.B.; Bowman, D.R.

    1989-04-11

    A photoconductive element of polycrystalline silicon is provided with intrinsic response time which does not limit overall circuit response. An undoped polycrystalline silicon layer is deposited by LPCVD to a selected thickness on silicon dioxide. The deposited polycrystalline silicon is then annealed at a selected temperature and for a time effective to obtain crystal sizes effective to produce an enhanced current output. The annealed polycrystalline layer is subsequently exposed and damaged by ion implantation to a damage factor effective to obtain a fast photoconductive response. 6 figs.

  1. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, H.; Lin-Liu, Y.R.; DeGrassie, J.S.

    1991-08-27

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other. 5 figures.

  2. Printed circuit dispersive transmission line

    DOEpatents

    Ikezi, Hiroyuki; Lin-Liu, Yuh-Ren; DeGrassie, John S.

    1991-01-01

    A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.

  3. Two digital video encoder circuits

    NASA Astrophysics Data System (ADS)

    Eldon, John A.

    1992-11-01

    Central to `multimedia' image processing is the desire to encode computer graphics data into a standard television signal, complete with line, field, and color subcarrier synchronizing information. The numerous incompatibilities between television and computer display standards render this operation far less trivial than it sounds to anyone who hasn't worked with both types of signals. To simplify the task of encoding computer graphics signals into standard NTSC (North America and Japan) or PAL (most of Europe) television format for display, broadcast, or recording, TRW LSI Products Inc. has introduced the two newest members of it multimedia integrated circuit family, the TMC22090 and TMC22190 digital video encoders.

  4. Automatic generation of signal processing integrated circuits

    SciTech Connect

    Pope, S.P.

    1985-01-01

    A system for the automated design of signal processing integrated circuits is described in this thesis. The system is based on a library of circuit cells, and a software package that can configure the cells into complete integrated circuits. The architecture of the cell library is optimized for low and medium bandwidth digital signal processing applications. Circuits designed with the system use a multiprocessor architecture. Input to the system is a design file written in a specialized programming language. Software emulation from the design file is used to verify performance. A two-pass silicon compiler is used to translate the design file into a mask-level description of an integrated circuit. A major goal of the project is to make the system useable by those with little or no formal training in integrated circuits. A second goal is to reduce the time and cost associated with performing an integrated circuit design, while still producing designs which are reasonably efficient in their use of the technology. Development of the system was guided by basic research on appropriate architectures and circuit constructs for signal processors. As part of this research an integrated circuit was designed which performs speech analysis and synthesis. This vocoder circuit is intended for use in low-bit-rate digital speech transmission systems.

  5. The p53 circuit board

    PubMed Central

    Sullivan, Kelly D.; Gallant-Behm, Corrie L.; Henry, Ryan E.; Fraikin, Jean-Luc; Espinosa, Joaquín M.

    2012-01-01

    The p53 tumor suppressor is embedded in a large gene network controlling diverse cellular and organismal phenotypes. Multiple signaling pathways converge onto p53 activation, mostly by relieving the inhibitory effects of its repressors, MDM2 and MDM4. In turn, signals originating from increased p53 activity diverge into distinct effector pathways to deliver a specific cellular response to the activating stimuli. Much attention has been devoted to dissecting how the various input pathways trigger p53 activation and how the activity of the p53 protein itself can be modulated by a plethora of co-factors and post-translational modifications. In this review we will focus instead on the multiple configurations of the effector pathways. We will discuss how p53-generated signals are transmitted, amplified, resisted and eventually integrated by downstream gene circuits operating at the transcriptional, post-transcriptional and post-translational level. We will also discuss how context-dependent variations in these gene circuits define the cellular response to p53 activation and how they may impact the clinical efficacy of p53-based targeted therapies. PMID:22333261

  6. Clocking and synchronization circuits in multiprocessor systems

    SciTech Connect

    Jeong, D.K.

    1989-01-01

    Microprocessors based on RISC (Reduced Instruction Set Computer) concepts have demonstrated an ability to provide more computing power at a given level of integration than conventional microprocessors. The next step is multiprocessors composed of RISC processing elements. Communication bandwidth among such microprocessors is critical in achieving efficient hardware utilization. This thesis focuses on the communication capability of VLSI circuits and presents new circuit techniques as a guide to build an interconnection network of VLSI microprocessors. Circuit techniques for PLL-based clock generation are described along with stability criteria. The main objective of the circuit is to realize a zero delay buffer. Experimental results show the feasibility of such circuits in VLSI. Synchronizer circuit configurations in both bipolar and MOS technology that best utilize each device, or overcome the technology limit using a bandwidth doubling technique are shown. Interface techniques including handshake mechanisms in such a system are also described.

  7. MULTI-ELECTRODE TUBE PULSE MEMORY CIRCUIT

    DOEpatents

    Gundlach, J.C.; Reeves, J.B.

    1958-05-20

    Control circuits are described for pulse memory devices for scalers and the like, and more particularly to a driving or energizing circuit for a polycathode gaseous discharge tube having an elongated anode and a successive series of cathodes spaced opposite the anode along its length. The circuit is so arranged as to utilize an arc discharge between the anode and a cathode to count a series of pulses. Upon application of an input pulse the discharge is made to occur between the anode and the next successive cathode, and an output pulse is produced when a particular subsequent cathode is reached. The circuit means for transfering the discharge by altering the anode potential and potential of the cathodes and interconnecting the cathodes constitutes the novel aspects of the invention. A low response time and reduced number of circuit components are the practical advantages of the described circuit.

  8. Diode-quad bridge circuit means

    NASA Technical Reports Server (NTRS)

    Harrison, D. R.; Dimeff, J. (Inventor)

    1975-01-01

    Diode-quad bridge circuit means is described for use as a transducer circuit or as a discriminator circuit. It includes: (1) a diode bridge having first, second, third, and fourth bridge terminals consecutively coupled together by four diodes polarized in circulating relationship; (2) a first impedance connected between the second bridge terminal and a circuit ground; (3) a second impedance connected between the fourth bridge terminal and the circuit ground; (4) a signal source having a first source terminal capacitively coupled to the first and third bridge terminals, and a second source terminal connected to the circuit ground; and (5) an output terminal coupled to the first bridge terminal and at which an output signal may be taken.

  9. Analog VLSI neural network integrated circuits

    NASA Technical Reports Server (NTRS)

    Kub, F. J.; Moon, K. K.; Just, E. A.

    1991-01-01

    Two analog very large scale integration (VLSI) vector matrix multiplier integrated circuit chips were designed, fabricated, and partially tested. They can perform both vector-matrix and matrix-matrix multiplication operations at high speeds. The 32 by 32 vector-matrix multiplier chip and the 128 by 64 vector-matrix multiplier chip were designed to perform 300 million and 3 billion multiplications per second, respectively. An additional circuit that has been developed is a continuous-time adaptive learning circuit. The performance achieved thus far for this circuit is an adaptivity of 28 dB at 300 KHz and 11 dB at 15 MHz. This circuit has demonstrated greater than two orders of magnitude higher frequency of operation than any previous adaptive learning circuit.

  10. Physical synthesis of quantum circuits using templates

    NASA Astrophysics Data System (ADS)

    Mirkhani, Zahra; Mohammadzadeh, Naser

    2016-06-01

    Similar to traditional CMOS circuits, quantum circuit design flow is divided into two main processes: logic synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit metrics because of no information sharing between logic synthesis and physical design processes, the concept of "physical synthesis" was introduced for quantum circuit flow, and a few techniques were proposed for it. Following that concept, in this paper a new approach for physical synthesis inspired by template matching idea in quantum logic synthesis is proposed to improve the latency of quantum circuits. Experiments show that by using template matching as a physical synthesis approach, the latency of quantum circuits can be improved by more than 23.55 % on average.

  11. Gas-Sensing Flip-Flop Circuits

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G.; Blaes, Brent R.; Williams, Roger; Ryan, Margaret A.

    1995-01-01

    Gas-sensing integrated circuits consisting largely of modified static random-access memories (SRAMs) undergoing development, building on experience gained in use of modified SRAMs as radiation sensors. Each SRAM memory cell includes flip-flop circuit; sensors exploit metastable state that lies between two stable states (corresponding to binary logic states) of flip-flop circuit. Voltages of metastable states vary with exposures of gas-sensitive resistors.

  12. Cost optimization in low volume VLSI circuits

    NASA Technical Reports Server (NTRS)

    Cook, K. B., Jr.; Kerns, D. V., Jr.

    1982-01-01

    The relationship of integrated circuit (IC) cost to electronic system cost is developed using models for integrated circuit cost which are based on design/fabrication approach. Emphasis is on understanding the relationship between cost and volume for custom circuits suitable for NASA applications. In this report, reliability is a major consideration in the models developed. Results are given for several typical IC designs using off the shelf, full custom, and semicustom IC's with single and double level metallization.

  13. Expert system to design communications circuits

    SciTech Connect

    Tolendino, L.F.; Vahle, M.O.

    1986-07-01

    An expert system has been created to aid the design of fiber optic based communications circuits. The design system is based on an Apollo workstation, LISP and CPSL, an in-house developed expert system language. The optical circuit is taken from design specification through hardware selection and circuit routing to the production of detailed schematics and routing guides. A database containing the entire fiber optic trunk system is also maintained.

  14. Integrated-Circuit Pseudorandom-Number Generator

    NASA Technical Reports Server (NTRS)

    Steelman, James E.; Beasley, Jeff; Aragon, Michael; Ramirez, Francisco; Summers, Kenneth L.; Knoebel, Arthur

    1992-01-01

    Integrated circuit produces 8-bit pseudorandom numbers from specified probability distribution, at rate of 10 MHz. Use of Boolean logic, circuit implements pseudorandom-number-generating algorithm. Circuit includes eight 12-bit pseudorandom-number generators, outputs are uniformly distributed. 8-bit pseudorandom numbers satisfying specified nonuniform probability distribution are generated by processing uniformly distributed outputs of eight 12-bit pseudorandom-number generators through "pipeline" of D flip-flops, comparators, and memories implementing conditional probabilities on zeros and ones.

  15. A microwave dielectric resonant oscillatory circuit

    NASA Astrophysics Data System (ADS)

    Sigov, A. S.; Shvartsburg, A. B.

    2016-07-01

    Bias currents in a thin dielectric nonconducting torus are investigated, and the resonant mode of excitation of these currents is established. The similarity of the frequency spectrum of such a dielectric element to the spectra of a classical Thomson oscillatory circuit and a metamaterial with negative permittivity is demonstrated. The resonant frequency of electromagnetic oscillations of the ring dielectric circuit and magnetic and electric fields of such a circuit under resonant excitation are determined.

  16. Multiplexer and time duration measuring circuit

    SciTech Connect

    Gray, Jr., James

    1980-01-01

    A multiplexer device is provided for multiplexing data in the form of randomly developed, variable width pulses from a plurality of pulse sources to a master storage. The device includes a first multiplexer unit which includes a plurality of input circuits each coupled to one of the pulse sources, with all input circuits being disabled when one input circuit receives an input pulse so that only one input pulse is multiplexed by the multiplexer unit at any one time.

  17. Modeling of transformers using circuit simulators

    SciTech Connect

    Archer, W.E.; Deveney, M.F.; Nagel, R.L.

    1994-07-01

    Transformers of two different designs; and unencapsulated pot core and an encapsulated toroidal core have been modeled for circuit analysis with circuit simulation tools. We selected MicroSim`s PSPICE and Anology`s SABER as the simulation tools and used experimental BH Loop and network analyzer measurements to generate the needed input data. The models are compared for accuracy and convergence using the circuit simulators. Results are presented which demonstrate the effects on circuit performance from magnetic core losses, eddy currents, and mechanical stress on the magnetic cores.

  18. Circuit For Control Of Electromechanical Prosthetic Hand

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr.

    1995-01-01

    Proposed circuit for control of electromechanical prosthetic hand derives electrical control signals from shoulder movements. Updated, electronic version of prosthesis, that includes two hooklike fingers actuated via cables from shoulder harness. Circuit built around favored shoulder harness, provides more dexterous movement, without incurring complexity of computer-controlled "bionic" or hydraulically actuated devices. Additional harness and potentiometer connected to similar control circuit mounted on other shoulder. Used to control stepping motor rotating hand about prosthetic wrist to one of number of angles consistent with number of digital outputs. Finger-control signals developed by circuit connected to first shoulder harness transmitted to prosthetic hand via sliprings at prosthetic wrist joint.

  19. High Speed Solid State Circuit Breaker

    NASA Technical Reports Server (NTRS)

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  20. Thermionic integrated circuit program: Final report

    SciTech Connect

    Wilde, D.K.; Lynn, D.K.; Hamilton, D.

    1988-05-01

    This report describes the development of an operational amplifier using radiation hardened Thermionic Integrated Circuits (TICs). The report is written as a tutorial to cover all aspects of the fabrication process and circuit development as well as the process and circuit modifications required to meet the integration requirements of the operational amplifier. Recent experimental results are discussed in which both devices and test circuit data are compared to theoretical computer code predictions. The development of compatible high-temperature thin-film resistors is also presented. Because the project is being terminated prior to the completion of the amplifier, suggestions are made for additional advance development.

  1. High temperature superconducting digital circuits and subsystems

    SciTech Connect

    Martens, J.S.; Pance, A.; Whiteley, S.R.; Char, K.; Johansson, M.F.; Lee, L.; Hietala, V.M.; Wendt, J.R.; Hou, S.Y.; Phillips, J.

    1993-10-01

    The advances in the fabrication of high temperature superconducting devices have enabled the demonstration of high performance and useful digital circuits and subsystems. The yield and uniformity of the devices is sufficient for circuit fabrication at the medium scale integration (MSI) level with performance not seen before at 77 K. The circuits demonstrated to date include simple gates, counters, analog to digital converters, and shift registers. All of these are mid-sized building blocks for potential applications in commercial and military systems. The processes used for these circuits and blocks will be discussed along with observed performance data.

  2. Quantization of lumped elements electrical circuits revisited

    NASA Astrophysics Data System (ADS)

    Lalumiere, Kevin; Najafi­-Yazdi, Alireza

    In 1995, the ``Les Houches'' seminar of Michel Devoret introduced a method to quantize lumped elements electrical circuits. This method has since been formalized using the matricial formalism, in particular by G. Burkard. Starting from these seminal contributions, we present a new algorithm to quantify electrical circuits. This algorithm unites the features of Devoret's and Burkad's approaches. We minimize the set of assumptions made so that the method can treat directly most electrical circuits. This includes circuits with resistances, mutual inductances, voltage and current sources. We conclude with a discussion about the choice of the basis in which the Hamiltonian operator should be written, an issue which is often overlooked.

  3. Q-switched laser prelase detection circuit

    NASA Technical Reports Server (NTRS)

    Lockard, George E.

    1991-01-01

    A compact electronic circuit was developed to detect prelasing in Q-swithed pulsed laser systems and once detected to shut down the laser before the next laser pulse occurs. The circuit is small, compact, and uses a minimum of components which makes it quite economical, thus readily lending itself to commercial applications. It can easily be incorporated into virtually any Q-switched laser system or reliability of a laser system by reducing a source of possible costly optical damage. The circuit operation and instrument requirements necessary to incorporate the circuit into a laser system are discussed.

  4. Digital circuits for computer applications: A compilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The innovations in this updated series of compilations dealing with electronic technology represent a carefully selected collection of digital circuits which have direct application in computer oriented systems. In general, the circuits have been selected as representative items of each section and have been included on their merits of having universal applications in digital computers and digital data processing systems. As such, they should have wide appeal to the professional engineer and scientist who encounter the fundamentals of digital techniques in their daily activities. The circuits are grouped as digital logic circuits, analog to digital converters, and counters and shift registers.

  5. Hybrid stretchable circuits on silicone substrate

    SciTech Connect

    Robinson, A. Aziz, A.; Liu, Q.; Suo, Z.; Lacour, S. P.

    2014-04-14

    When rigid and stretchable components are integrated onto a single elastic carrier substrate, large strain heterogeneities appear in the vicinity of the deformable-non-deformable interfaces. In this paper, we report on a generic approach to manufacture hybrid stretchable circuits where commercial electronic components can be mounted on a stretchable circuit board. Similar to printed circuit board development, the components are electrically bonded on the elastic substrate and interconnected with stretchable electrical traces. The substrate—a silicone matrix carrying concentric rigid disks—ensures both the circuit elasticity and the mechanical integrity of the most fragile materials.

  6. Precision measurements of a simple chaotic circuit

    NASA Astrophysics Data System (ADS)

    Kiers, Ken; Schmidt, Dory; Sprott, J. C.

    2004-04-01

    We describe a simple nonlinear electrical circuit that can be used to study chaotic phenomena. The circuit employs simple electronic elements such as diodes, resistors, and operational amplifiers, and is easy to construct. A novel feature of the circuit is its use of an almost ideal nonlinear element, which is straightforward to model theoretically and leads to excellent agreement between experiment and theory. For example, comparisons of bifurcation points and power spectra give agreement to within 1%. The circuit yields a broad range of behavior and is well suited for qualitative demonstrations and as a serious research tool.

  7. Towards programmable plant genetic circuits.

    PubMed

    Medford, June I; Prasad, Ashok

    2016-07-01

    Synthetic biology enables the construction of genetic circuits with predictable gene functions in plants. Detailed quantitative descriptions of the transfer function or input-output function for genetic parts (promoters, 5' and 3' untranslated regions, etc.) are collected. These data are then used in computational simulations to determine their robustness and desired properties, thereby enabling the best components to be selected for experimental testing in plants. In addition, the process forms an iterative workflow which allows vast improvement to validated elements with sub-optimal function. These processes enable computational functions such as digital logic in living plants and follow the pathway of technological advances which took us from vacuum tubes to cell phones. PMID:27297052

  8. TIME CALIBRATED OSCILLOSCOPE SWEEP CIRCUIT

    DOEpatents

    Smith, V.L.; Carstensen, H.K.

    1959-11-24

    An improved time calibrated sweep circuit is presented, which extends the range of usefulness of conventional oscilloscopes as utilized for time calibrated display applications in accordance with U. S. Patent No. 2,832,002. Principal novelty resides in the provision of a pair of separate signal paths, each of which is phase and amplitude adjustable, to connect a high-frequency calibration oscillator to the output of a sawtooth generator also connected to the respective horizontal deflection plates of an oscilloscope cathode ray tube. The amplitude and phase of the calibration oscillator signals in the two signal paths are adjusted to balance out feedthrough currents capacitively coupled at high frequencies of the calibration oscillator from each horizontal deflection plate to the vertical plates of the cathode ray tube.

  9. Flexible phosphorene devices and circuits

    NASA Astrophysics Data System (ADS)

    Zhu, Weinan; Yogeesh, Maruthi N.; Akinwande, Deji

    2015-05-01

    Two-dimensional (2D) semiconductors with high carrier mobilities and sizeable bandgap are desirable for future high-speed and low power mechanically flexible nanoelectronics. In this work, we report encapsulated bottom-gated black phosphorus (BP) field-effect transistors (FETs) on flexible polyimide affording maximum carrier mobility of about 310cm2/V•s and current on/off ratio exceeding 103. Essential circuits of flexible electronic systems enabled by the device ambipolar functionality, high-mobility and current saturation are demonstrated in this work, including digital inverter, frequency doubler, and analog amplifiers featuring a voltage gain of ~8.7, which is the state-of-the-art value for flexible 2D semiconductor based amplifiers. In addition, we demonstrate the single FET based flexible BP amplitude-modulated (AM) demodulator, an active stage in radio receivers.

  10. Atemporal diagrams for quantum circuits

    SciTech Connect

    Griffiths, Robert B.; Wu Shengjun; Yu Li; Cohen, Scott M.

    2006-05-15

    A system of diagrams is introduced that allows the representation of various elements of a quantum circuit, including measurements, in a form which makes no reference to time (hence 'atemporal'). It can be used to relate quantum dynamical properties to those of entangled states (map-state duality), and suggests useful analogies, such as the inverse of an entangled ket. Diagrams clarify the role of channel kets, transition operators, dynamical operators (matrices), and Kraus rank for noisy quantum channels. Positive (semidefinite) operators are represented by diagrams with a symmetry that aids in understanding their connection with completely positive maps. The diagrams are used to analyze standard teleportation and dense coding, and for a careful study of unambiguous (conclusive) teleportation. A simple diagrammatic argument shows that a Kraus rank of 3 is impossible for a one-qubit channel modeled using a one-qubit environment in a mixed state.

  11. Semiconductor materials and microelectronic circuits

    NASA Astrophysics Data System (ADS)

    Kolesar, Edward S.

    Microminiaturization developments in IC systems have dramatically increased the reliability and performance of electronic components while reducing their physical size and power requirements; these advancements have pervasively affected weapons systems design efforts. Built-in self-test circuitry has greatly reduced maintenance problems and improved overall systems reliability. Increasing circuit complexity has also led to a major expansion of key military operational capabilities for reconnaissance, surveillance, and target acquisition. It is expected that Si-based ICs will continue to dominate high power solid-state switches in hypervelocity projectiles and beam weapons, while GaAs will remain the most commonly employed material in microwave and mm-wave devices for EW, radars, smart weapons, and communications.

  12. Sequential power-up circuit

    DOEpatents

    Kronberg, James W.

    1992-01-01

    A sequential power-up circuit for starting several electrical load elements in series to avoid excessive current surge, comprising a voltage ramp generator and a set of voltage comparators, each comparator having a different reference voltage and interfacing with a switch that is capable of turning on one of the load elements. As the voltage rises, it passes the reference voltages one at a time and causes the switch corresponding to that voltage to turn on its load element. The ramp is turned on and off by a single switch or by a logic-level electrical signal. The ramp rate for turning on the load element is relatively slow and the rate for turning the elements off is relatively fast. Optionally, the duration of each interval of time between the turning on of the load elements is programmable.

  13. Sequential power-up circuit

    DOEpatents

    Kronberg, J.W.

    1992-06-02

    A sequential power-up circuit for starting several electrical load elements in series to avoid excessive current surge, comprising a voltage ramp generator and a set of voltage comparators, each comparator having a different reference voltage and interfacing with a switch that is capable of turning on one of the load elements. As the voltage rises, it passes the reference voltages one at a time and causes the switch corresponding to that voltage to turn on its load element. The ramp is turned on and off by a single switch or by a logic-level electrical signal. The ramp rate for turning on the load element is relatively slow and the rate for turning the elements off is relatively fast. Optionally, the duration of each interval of time between the turning on of the load elements is programmable. 2 figs.

  14. Shapeable short circuit resistant capacitor

    DOEpatents

    Taylor, Ralph S.; Myers, John D.; Baney, William J.

    2015-10-06

    A ceramic short circuit resistant capacitor that is bendable and/or shapeable to provide a multiple layer capacitor that is extremely compact and amenable to desirable geometries. The capacitor that exhibits a benign failure mode in which a multitude of discrete failure events result in a gradual loss of capacitance. Each event is a localized event in which localized heating causes an adjacent portion of one or both of the electrodes to vaporize, physically cleaning away electrode material from the failure site. A first metal electrode, a second metal electrode, and a ceramic dielectric layer between the electrodes are thin enough to be formed in a serpentine-arrangement with gaps between the first electrode and the second electrode that allow venting of vaporized electrode material in the event of a benign failure.

  15. Integrated Circuit Electromagnetic Immunity Handbook

    NASA Astrophysics Data System (ADS)

    Sketoe, J. G.

    2000-08-01

    This handbook presents the results of the Boeing Company effort for NASA under contract NAS8-98217. Immunity level data for certain integrated circuit parts are discussed herein, along with analytical techniques for applying the data to electronics systems. This handbook is built heavily on the one produced in the seventies by McDonnell Douglas Astronautics Company (MDAC, MDC Report E1929 of 1 August 1978, entitled Integrated Circuit Electromagnetic Susceptibility Handbook, known commonly as the ICES Handbook, which has served countless systems designers for over 20 years). Sections 2 and 3 supplement the device susceptibility data presented in section 4 by presenting information on related material required to use the IC susceptibility information. Section 2 concerns itself with electromagnetic susceptibility analysis and serves as a guide in using the information contained in the rest of the handbook. A suggested system hardening requirements is presented in this chapter. Section 3 briefly discusses coupling and shielding considerations. For conservatism and simplicity, a worst case approach is advocated to determine the maximum amount of RF power picked up from a given field. This handbook expands the scope of the immunity data in this Handbook is to of 10 MHz to 10 GHz. However, the analytical techniques provided are applicable to much higher frequencies as well. It is expected however, that the upper frequency limit of concern is near 10 GHz. This is due to two factors; the pickup of microwave energy on system cables and wiring falls off as the square of the wavelength, and component response falls off at a rapid rate due to the effects of parasitic shunt paths for the RF energy. It should be noted also that the pickup on wires and cables does not approach infinity as the frequency decreases (as would be expected by extrapolating the square law dependence of the high frequency roll-off to lower frequencies) but levels off due to mismatch effects.

  16. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Design of control circuits on closed circuit principle. 236.5 Section 236.5 Transportation Other Regulations Relating to Transportation (Continued..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits...

  17. A Better Way to Drive "RLC" Circuits

    ERIC Educational Resources Information Center

    Aguilar, Horacio Munguia

    2009-01-01

    An electronic circuit for controlling "RLC" experiments is shown. This arrangement does not employ a function generator, which makes it more suitable when a wide range of "R," "L" and "C" values is required and a relatively high current is involved. This circuit can be used for driven and undriven DC experiments. (Contains 5 figures.)

  18. Analysis of circuits including magnetic cores (MTRAC)

    NASA Technical Reports Server (NTRS)

    Hanzen, G. R.; Nitzan, D.; Herndon, J. R.

    1972-01-01

    Development of automated circuit analysis computer program to provide transient analysis of circuits with magnetic cores is discussed. Allowance is made for complications caused by nonlinearity of switching core model and magnetic coupling among loop currents. Computer program is conducted on Univac 1108 computer using FORTRAN IV.

  19. Circuit II--A Conversational Graphical Interface.

    ERIC Educational Resources Information Center

    Singer, Ronald A.

    1993-01-01

    Provides an overview of Circuit II, an interactive system that provides users with a graphical representation of an electronic circuit within which questions may be posed and manipulated, and discusses how mouse selections have analogous roles to certain natural language features, such as anaphora, deixis, and ellipsis. (13 references) (EA)

  20. Apollo 14 mission circuit breaker anomaly

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Continuity through the circuit breaker in the mechanically closed condition was prevented by a foreign substance on the contact surface onboard Apollo 14. It was concluded that this was the only failure of this type in over 3400 units that were flown, and since no circuit breaker is a single-point failure for crew safety or mission success, no corrective action was taken.

  1. A Differential Magnetic Circuit for Teaching Purposes

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2010-01-01

    A differential magnetic circuit (magnetic bridge) is described. The circuit separates the magnetic field sensor and the sample under study. A Hall probe serves as the sensor. The signal from the sensor can be enhanced by concentrating the magnetic flux. The magnetic bridge works even with dc magnetic fields. The device is used for displaying…

  2. Control of oscillations in a discharge circuit

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y.

    1972-01-01

    Development of electric discharge circuit damping element which increases in resistance with current and time is described. Damping element is resistor made of tungsten wire which has large resistance-temperature coefficient. Specifications of tungsten resistor and incorporation into circuit are explained.

  3. Low power SEU immune CMOS memory circuits

    NASA Technical Reports Server (NTRS)

    Liu, M. N.; Whitaker, Sterling

    1992-01-01

    The authors report a design improvement for CMOS static memory circuits hardened against single event upset (SEU) using a recently proposed logic/circuit design technique. This improvement drastically reduces static power consumption, reduces the number of transistors required in a D flip-flop design, and eliminates the possibility of capturing an upset state in the slave section during a clock transition.

  4. Electronic switches and control circuits: A compilation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The innovations in this updated series of compilations dealing with electronic technology represents a carefully selected collection of items on electronic switches and control circuits. Most of the items are based on well-known circuit design concepts that have been simplified or refined to meet NASA's demanding requirement for reliability, simplicity, fail-safe characteristics, and the capability of withstanding environmental extremes.

  5. Latent phenotypes pervade gene regulatory circuits

    PubMed Central

    2014-01-01

    Background Latent phenotypes are non-adaptive byproducts of adaptive phenotypes. They exist in biological systems as different as promiscuous enzymes and genome-scale metabolic reaction networks, and can give rise to evolutionary adaptations and innovations. We know little about their prevalence in the gene expression phenotypes of regulatory circuits, important sources of evolutionary innovations. Results Here, we study a space of more than sixteen million three-gene model regulatory circuits, where each circuit is represented by a genotype, and has one or more functions embodied in one or more gene expression phenotypes. We find that the majority of circuits with single functions have latent expression phenotypes. Moreover, the set of circuits with a given spectrum of functions has a repertoire of latent phenotypes that is much larger than that of any one circuit. Most of this latent repertoire can be easily accessed through a series of small genetic changes that preserve a circuit’s main functions. Both circuits and gene expression phenotypes that are robust to genetic change are associated with a greater number of latent phenotypes. Conclusions Our observations suggest that latent phenotypes are pervasive in regulatory circuits, and may thus be an important source of evolutionary adaptations and innovations involving gene regulation. PMID:24884746

  6. Circuits in the Sun: Solar Panel Physics

    ERIC Educational Resources Information Center

    Gfroerer, Tim

    2013-01-01

    Typical commercial solar panels consist of approximately 60 individual photovoltaic cells connected in series. Since the usual Kirchhoff rules apply, the current is uniform throughout the circuit, while the electric potential of the individual devices is cumulative. Hence, a solar panel is a good analog of a simple resistive series circuit, except…

  7. The Short Circuit Model of Reading.

    ERIC Educational Resources Information Center

    Lueers, Nancy M.

    The name "short circuit" has been given to this model because, in many ways, it adequately describes what happens bioelectrically in the brain. The "short-circuiting" factors include linguistic, sociocultural, attitudinal and motivational, neurological, perceptual, and cognitive factors. Research is reviewed on ways in which each one affects any…

  8. Design of hysteresis circuits using differential amplifiers

    NASA Technical Reports Server (NTRS)

    Cooke, W. A.

    1971-01-01

    Design equations for hysteresis circuit are based on the following assumptions: amplifier input impedance is larger than source impedance; amplifier output impedance is less than load impedance; and amplifier switches state when differential input voltage is approximately zero. Circuits are designed to any given specifications.

  9. Continuous, Full-Circle Arctangent Circuit

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Howard, David E.; Smith, Dennis A.

    2005-01-01

    A circuit generates an analog voltage proportional to an angle, in response to two sinusoidal input voltages having magnitudes proportional to the sine and cosine of the angle, respectively. That is to say, given input voltages proportional to sin(Omega(t))sin(Theta) and sin(Omega(t))cos(Theta) [where Theta denotes the angle, mega denotes 2(pi) x a carrier frequency, and t denotes time], the circuit generates a steady voltage proportional to Theta. The output voltage varies continuously from its minimum to its maximum value as Theta varies from -180deg to 180deg. While the circuit could accept input modulated sine and cosine signals from any source, it must be noted that such signals are typical of the outputs of shaft-angle resolvers in electromagnetic actuators used to measure and control shaft angles for diverse purposes like aiming scientific instruments and adjusting valve openings. In effect, the circuit is an analog computer that calculates the arctangent of the ratio between the sine and cosine signals. The full-circle angular range of this arctangent circuit stands in contrast to the range of prior analog arctangent circuits, which is from slightly greater than -90deg to slightly less than +90deg. Moreover, for applications in which continuous variation of output is preferred to discrete increments of output, this circuit offers a clear advantage over resolver- to-digital integrated circuits.

  10. Understanding the Behaviour of Infinite Ladder Circuits

    ERIC Educational Resources Information Center

    Ucak, C.; Yegin, K.

    2008-01-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

  11. 30 CFR 56.6407 - Circuit testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing... series or the resistance of multiple balanced series to be connected in parallel prior to...

  12. 30 CFR 56.6407 - Circuit testing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing... series or the resistance of multiple balanced series to be connected in parallel prior to...

  13. 30 CFR 57.6407 - Circuit testing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Circuit testing. 57.6407 Section 57.6407... Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument... parallel prior to their connection to the blasting line; (3) Continuity of blasting lines prior to...

  14. 30 CFR 57.6407 - Circuit testing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Circuit testing. 57.6407 Section 57.6407... Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument... parallel prior to their connection to the blasting line; (3) Continuity of blasting lines prior to...

  15. 30 CFR 57.6407 - Circuit testing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit testing. 57.6407 Section 57.6407... Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument... parallel prior to their connection to the blasting line; (3) Continuity of blasting lines prior to...

  16. 30 CFR 56.6407 - Circuit testing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing... series or the resistance of multiple balanced series to be connected in parallel prior to...

  17. 30 CFR 56.6407 - Circuit testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing... series or the resistance of multiple balanced series to be connected in parallel prior to...

  18. 30 CFR 56.6407 - Circuit testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Circuit testing. 56.6407 Section 56.6407 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Electric Blasting § 56.6407 Circuit testing. A...

  19. 30 CFR 57.6407 - Circuit testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Circuit testing. 57.6407 Section 57.6407... Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument... parallel prior to their connection to the blasting line; (3) Continuity of blasting lines prior to...

  20. Formal hardware verification of digital circuits

    NASA Technical Reports Server (NTRS)

    Joyce, J.; Seger, C.-J.

    1991-01-01

    The use of formal methods to verify the correctness of digital circuits is less constrained by the growing complexity of digital circuits than conventional methods based on exhaustive simulation. This paper briefly outlines three main approaches to formal hardware verification: symbolic simulation, state machine analysis, and theorem-proving.

  1. Electric Circuit Theory--Computer Illustrated Text.

    ERIC Educational Resources Information Center

    Riches, Brian

    1990-01-01

    Discusses the use of a computer-illustrated text (CIT) with integrated software to teach electric circuit theory to college students. Examples of software use are given, including simple animation, graphical displays, and problem-solving programs. Issues affecting electric circuit theory instruction are also addressed, including mathematical…

  2. SSCFI: Autonomous fault isolation in communications circuits

    SciTech Connect

    Worrest, R.; Zito-Wolf, R.; Wang, Hongbin; Goyal, S.

    1996-12-31

    SSCFI is a rule-based expert system that diagnoses problems in a wide variety of {open_quotes}special circuits,{close_quotes} that is, telephone circuits other than regular switched business and residential lines. Special circuits are significantly more complex than regular circuits, and hence more difficult to diagnose. SSCFI diagnoses problems by recursively partitioning the circuit until the responsible fault is isolated. SSCFI selects which circuit to work on, reads its design, selects and initiates analog and digital tests via remotely-activated test equipment, interprets the results of each test in the context of the circuit design, and when done, writes out a detailed description of the problem found and routes it to the party responsible for its repair. SSCFI is entirely autonomous in operation. SSCFI has become an essential element of GTE`s special circuit maintenance operations. It has been in service since 1991 and has been in operation at all GTE`s US sites since 1994. SSCFI testing saves millions of dollars annually and significantly improves the uniformity of testing and quality of the resulting diagnoses. This paper discusses the domain, architecture, and development of the SSCFI system, and the key factors and techniques that made it successful. Lastly, two current projects building on SSCFI`s expertise are discussed -- interactive test assistance and automatic design database cleanup.

  3. Textbook Error: Short Circuiting on Electrochemical Cell

    ERIC Educational Resources Information Center

    Bonicamp, Judith M.; Clark, Roy W.

    2007-01-01

    Short circuiting an electrochemical cell is an unreported but persistent error in the electrochemistry textbooks. It is suggested that diagrams depicting a cell delivering usable current to a load be postponed, the theory of open-circuit galvanic cells is explained, the voltages from the tables of standard reduction potentials is calculated and…

  4. Adapting Aquatic Circuit Training for Special Populations.

    ERIC Educational Resources Information Center

    Thome, Kathleen

    1980-01-01

    The author discusses how land activities can be adapted to water so that individuals with handicapping conditions can participate in circuit training activities. An initial section lists such organizational procedures as providing vocal and/or visual cues for activities, having assistants accompany the performers throughout the circuit, and…

  5. Topological properties of linear circuit lattices.

    PubMed

    Albert, Victor V; Glazman, Leonid I; Jiang, Liang

    2015-05-01

    Motivated by the topologically insulating circuit of capacitors and inductors proposed and tested by Jia et al. [arXiv:1309.0878], we present a related circuit with fewer elements per site. The normal mode frequency matrix of our circuit is unitarily equivalent to the hopping matrix of a quantum spin Hall insulator, and we identify perturbations that do not backscatter the circuit's edge modes. The idea behind these models is generalized, providing a platform to simulate tunable and locally accessible lattices with arbitrary complex spin-dependent hopping of any range. A simulation of a non-Abelian Aharonov-Bohm effect using such linear circuit designs is discussed. PMID:25978235

  6. Trigger circuits for the PHENIX electromagnetic calorimeter

    SciTech Connect

    Frank, S.S.; Britton, C.L. Jr.; Winterberg, A.L.; Young, G.R.

    1997-11-01

    Monolithic and discrete circuits have been developed to provide trigger signals for the PHENIX electromagnetic calorimeter detector. These trigger circuits are deadtimeless and create overlapping 4 by 4 energy sums, a cosmic muon trigger, and a 144 channel energy sum. The front end electronics of the PHENIX system sample the energy and timing channels at each bunch crossing (BC) but it is not known immediately if this data is of interest. The information from the trigger circuits is used to determine if the data collected is of interest and should be digitized and stored or discarded. This paper presents details of the design, issues affecting circuit performance, characterization of prototypes fabricated in 1.2 {micro}m Orbit CMOS, and integration of the circuits into the EMCal electronics system.

  7. Reusable vibration resistant integrated circuit mounting socket

    DOEpatents

    Evans, Craig N.

    1995-01-01

    This invention discloses a novel form of socket for integrated circuits to be mounted on printed circuit boards. The socket uses a novel contact which is fabricated out of a bimetallic strip with a shape which makes the end of the strip move laterally as temperature changes. The end of the strip forms a barb which digs into an integrated circuit lead at normal temperatures and holds it firmly in the contact, preventing loosening and open circuits from vibration. By cooling the contact containing the bimetallic strip the barb end can be made to release so that the integrated circuit lead can be removed from the socket without damage either to the lead or to the socket components.

  8. Circuit design tool. User's manual, revision 2

    NASA Technical Reports Server (NTRS)

    Miyake, Keith M.; Smith, Donald E.

    1992-01-01

    The CAM chip design was produced in a UNIX software environment using a design tool that supports definition of digital electronic modules, composition of these modules into higher level circuits, and event-driven simulation of these circuits. Our design tool provides an interface whose goals include straightforward but flexible primitive module definition and circuit composition, efficient simulation, and a debugging environment that facilitates design verification and alteration. The tool provides a set of primitive modules which can be composed into higher level circuits. Each module is a C-language subroutine that uses a set of interface protocols understood by the design tool. Primitives can be altered simply by recoding their C-code image; in addition new primitives can be added allowing higher level circuits to be described in C-code rather than as a composition of primitive modules--this feature can greatly enhance the speed of simulation.

  9. On equivalent resistance of electrical circuits

    NASA Astrophysics Data System (ADS)

    Kagan, Mikhail

    2015-01-01

    While the standard (introductory physics) way of computing the equivalent resistance of nontrivial electrical circuits is based on Kirchhoff's rules, there is a mathematically and conceptually simpler approach, called the method of nodal potentials, whose basic variables are the values of the electric potential at the circuit's nodes. In this paper, we review the method of nodal potentials and illustrate it using the Wheatstone bridge as an example. We then derive a closed-form expression for the equivalent resistance of a generic circuit, which we apply to a few sample circuits. The result unveils a curious interplay between electrical circuits, matrix algebra, and graph theory and its applications to computer science. The paper is written at a level accessible by undergraduate students who are familiar with matrix arithmetic. Additional proofs and technical details are provided in appendices.

  10. Remote tuning of NMR probe circuits.

    PubMed

    Kodibagkar, V D; Conradi, M S

    2000-05-01

    There are many circumstances in which the probe tuning adjustments cannot be located near the rf NMR coil. These may occur in high-temperature NMR, low-temperature NMR, and in the use of magnets with small diameter access bores. We address here circuitry for connecting a fixed-tuned probe circuit by a transmission line to a remotely located tuning network. In particular, the bandwidth over which the probe may be remotely tuned while keeping the losses in the transmission line acceptably low is considered. The results show that for all resonant circuit geometries (series, parallel, series-parallel), overcoupling of the line to the tuned circuit is key to obtaining a large tuning bandwidth. At equivalent extents of overcoupling, all resonant circuit geometries have nearly equal remote tuning bandwidths. Particularly for the case of low-loss transmission line, the tuning bandwidth can be many times the tuned circuit's bandwidth, f(o)/Q. PMID:10783273

  11. Progress in organic integrated circuit manufacture

    NASA Astrophysics Data System (ADS)

    Taylor, D. Martin

    2016-02-01

    This review article focuses on the development of processes for the manufacture of organic electronic circuits. Beginning with the first report of an organic transistor it highlights the key developments leading to the successful manufacture of microprocessors and other complex circuits incorporating organic transistors. Both batch processing (based on silicon integrated circuit technology) as well as mass-printing, roll-to-roll (R2R) approaches are discussed. Currently, the best circuit performances are achieved using batch processing. It is suggested that an emerging, large mass-market for electronic tags may dictate that R2R manufacture will likely be required to meet the high throughput rates needed. However, significant improvements in resolution and registration are necessary to achieve increased circuit operating speeds.

  12. Synthesis of logic circuits with evolutionary algorithms

    SciTech Connect

    JONES,JAKE S.; DAVIDSON,GEORGE S.

    2000-01-26

    In the last decade there has been interest and research in the area of designing circuits with genetic algorithms, evolutionary algorithms, and genetic programming. However, the ability to design circuits of the size and complexity required by modern engineering design problems, simply by specifying required outputs for given inputs has as yet eluded researchers. This paper describes current research in the area of designing logic circuits using an evolutionary algorithm. The goal of the research is to improve the effectiveness of this method and make it a practical aid for design engineers. A novel method of implementing the algorithm is introduced, and results are presented for various multiprocessing systems. In addition to evolving standard arithmetic circuits, work in the area of evolving circuits that perform digital signal processing tasks is described.

  13. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... circuits. (a) Each power source must be protected against overcurrent. Overcurrent devices for generators... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent... 46 Shipping 1 2012-10-01 2012-10-01 false Overcurrent protection and switched circuits....

  14. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... circuits. (a) Each power source must be protected against overcurrent. Overcurrent devices for generators... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent... 46 Shipping 1 2013-10-01 2013-10-01 false Overcurrent protection and switched circuits....

  15. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... circuits. (a) Each power source must be protected against overcurrent. Overcurrent devices for generators... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent... 46 Shipping 1 2010-10-01 2010-10-01 false Overcurrent protection and switched circuits....

  16. 46 CFR 28.860 - Overcurrent protection and switched circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... circuits. (a) Each power source must be protected against overcurrent. Overcurrent devices for generators... steering circuit, each circuit must be protected against both overload and short circuit. Each overcurrent... 46 Shipping 1 2014-10-01 2014-10-01 false Overcurrent protection and switched circuits....

  17. 14 CFR 23.1357 - Circuit protective devices.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Circuit protective devices. 23.1357 Section... Systems and Equipment § 23.1357 Circuit protective devices. (a) Protective devices, such as fuses or circuit breakers, must be installed in all electrical circuits other than— (1) Main circuits of...

  18. 24 CFR 3280.805 - Branch circuits required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., two or more 20-ampere appliance branch circuits, in addition to the branch circuit specified in § 3280... accordance with the following: (i) Ampere rating of fixed appliances not over 50 percent of circuit rating if...) are on same circuit; (ii) For fixed appliances on a circuit without lighting outlets, the sum of...

  19. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved circuit schemes. 75.900-2 Section 75... Alternating Current Circuits § 75.900-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuit required by § 75.900: (a) Ground check...

  20. 14 CFR 23.1357 - Circuit protective devices.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Circuit protective devices. 23.1357 Section... Systems and Equipment § 23.1357 Circuit protective devices. (a) Protective devices, such as fuses or circuit breakers, must be installed in all electrical circuits other than— (1) Main circuits of...

  1. 24 CFR 3280.805 - Branch circuits required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., two or more 20-ampere appliance branch circuits, in addition to the branch circuit specified in § 3280... accordance with the following: (i) Ampere rating of fixed appliances not over 50 percent of circuit rating if...) are on same circuit; (ii) For fixed appliances on a circuit without lighting outlets, the sum of...

  2. 24 CFR 3280.805 - Branch circuits required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., two or more 20-ampere appliance branch circuits, in addition to the branch circuit specified in § 3280... accordance with the following: (i) Ampere rating of fixed appliances not over 50 percent of circuit rating if...) are on same circuit; (ii) For fixed appliances on a circuit without lighting outlets, the sum of...

  3. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Approved circuit schemes. 75.900-2 Section 75... Alternating Current Circuits § 75.900-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuit required by § 75.900: (a) Ground check...

  4. 14 CFR 23.1357 - Circuit protective devices.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Circuit protective devices. 23.1357 Section... Systems and Equipment § 23.1357 Circuit protective devices. (a) Protective devices, such as fuses or circuit breakers, must be installed in all electrical circuits other than— (1) Main circuits of...

  5. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved circuit schemes. 75.900-2 Section 75... Alternating Current Circuits § 75.900-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuit required by § 75.900: (a) Ground check...

  6. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved circuit schemes. 75.900-2 Section 75... Alternating Current Circuits § 75.900-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuit required by § 75.900: (a) Ground check...

  7. 14 CFR 23.1357 - Circuit protective devices.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Circuit protective devices. 23.1357 Section... Systems and Equipment § 23.1357 Circuit protective devices. (a) Protective devices, such as fuses or circuit breakers, must be installed in all electrical circuits other than— (1) Main circuits of...

  8. 30 CFR 75.900-2 - Approved circuit schemes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Approved circuit schemes. 75.900-2 Section 75... Alternating Current Circuits § 75.900-2 Approved circuit schemes. The following circuit schemes will be regarded as providing the necessary protection to the circuit required by § 75.900: (a) Ground check...

  9. 24 CFR 3280.805 - Branch circuits required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., two or more 20-ampere appliance branch circuits, in addition to the branch circuit specified in § 3280... accordance with the following: (i) Ampere rating of fixed appliances not over 50 percent of circuit rating if...) are on same circuit; (ii) For fixed appliances on a circuit without lighting outlets, the sum of...

  10. 49 CFR 234.269 - Cut-out circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Cut-out circuits. 234.269 Section 234.269..., Inspection, and Testing Inspections and Tests § 234.269 Cut-out circuits. Each cut-out circuit shall be... of this section, a cut-out circuit is any circuit which overrides the operation of automatic...

  11. 49 CFR 236.54 - Minimum length of track circuit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Minimum length of track circuit. 236.54 Section... Instructions: All Systems Track Circuits § 236.54 Minimum length of track circuit. When a track circuit shorter than maximum inner wheelbase of any locomotive or car operated over such track circuit is used...

  12. 30 CFR 75.900-1 - Circuit breakers; location.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit breakers; location. 75.900-1 Section 75... Alternating Current Circuits § 75.900-1 Circuit breakers; location. Circuit breakers used to protect low-and medium-voltage circuits underground shall be located in areas which are accessible for...

  13. 30 CFR 77.904 - Identification of circuit breakers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers. 77.904... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.904 Identification of circuit breakers. Circuit breakers shall be labeled to show which circuits they control unless identification...

  14. 49 CFR 236.54 - Minimum length of track circuit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Minimum length of track circuit. 236.54 Section... Instructions: All Systems Track Circuits § 236.54 Minimum length of track circuit. When a track circuit shorter than maximum inner wheelbase of any locomotive or car operated over such track circuit is used...

  15. A Parallel Genetic Algorithm for Automated Electronic Circuit Design

    NASA Technical Reports Server (NTRS)

    Lohn, Jason D.; Colombano, Silvano P.; Haith, Gary L.; Stassinopoulos, Dimitris; Norvig, Peter (Technical Monitor)

    2000-01-01

    We describe a parallel genetic algorithm (GA) that automatically generates circuit designs using evolutionary search. A circuit-construction programming language is introduced and we show how evolution can generate practical analog circuit designs. Our system allows circuit size (number of devices), circuit topology, and device values to be evolved. We present experimental results as applied to analog filter and amplifier design tasks.

  16. Light Sources and Ballast Circuits

    NASA Astrophysics Data System (ADS)

    Yorifuji, Takashi; Sakai, Makoto; Yasuda, Takeo; Maehara, Akiyoshi; Okada, Atsunori; Gouriki, Takeshi; Mannami, Tomoaki

    discharge models were reported. Further, studies on ultra high-pressure mercury lamps as light sources for projectors are becoming the mainstream of HID lamp related researches. For high-pressure sodium lamps, many studies on plant growing and pest control utilizing low insect attracting aspects were also reported in 2006. Additionally, for discharge lamps, the minimum sustaining electric power for arc tubes employed in electrode-less compact fluorescent lamps was investigated. For Hg-free rare-gas fluorescent lamps, a luminance of 10,000cd/m2 was attained by a 1 meter-long external duplex spiral electrode prototype using Xe/Ne barrier discharge. As to startup circuits, the commercialization of energy saving and high value added products mainly associated with fluorescent lamps and HID lamps are becoming common. Further, the miniaturization of startup circuits for self electronic-ballasted lamps has advanced. Speaking of the overall light sources and startup circuits in 2006 and with the enforcement of RoHS in Europe in July, the momentum toward hazardous substance-free and energy saving initiatives has been enhanced from the perspective of protecting the global environment. It is anticipated that similar restrictions will be globally enforced in the future.

  17. OptCircuit: An optimization based method for computational design of genetic circuits

    PubMed Central

    Dasika, Madhukar S; Maranas, Costas D

    2008-01-01

    Background Recent years has witnessed an increasing number of studies on constructing simple synthetic genetic circuits that exhibit desired properties such as oscillatory behavior, inducer specific activation/repression, etc. It has been widely acknowledged that that task of building circuits to meet multiple inducer-specific requirements is a challenging one. This is because of the incomplete description of component interactions compounded by the fact that the number of ways in which one can chose and interconnect components, increases exponentially with the number of components. Results In this paper we introduce OptCircuit, an optimization based framework that automatically identifies the circuit components from a list and connectivity that brings about the desired functionality. Multiple literature sources are used to compile a comprehensive compilation of kinetic descriptions of promoter-protein pairs. The dynamics that govern the interactions between the elements of the genetic circuit are currently modeled using deterministic ordinary differential equations but the framework is general enough to accommodate stochastic simulations. The desired circuit response is abstracted as the maximization/minimization of an appropriately constructed objective function. Computational results for a toggle switch example demonstrate the ability of the framework to generate the complete list of circuit designs of varying complexity that exhibit the desired response. Designs identified for a genetic decoder highlight the ability of OptCircuit to suggest circuit configurations that go beyond the ones compatible with digital logic-based design principles. Finally, the results obtained from the concentration band detector example demonstrate the ability of OptCircuit to design circuits whose responses are contingent on the level of external inducer as well as pinpoint parameters for modification to rectify an existing (non-functional) biological circuit and restore

  18. Ion implanted dielectric elastomer circuits

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin M.; Rosset, Samuel; Anderson, Iain A.; Shea, Herbert R.

    2013-06-01

    Starfish and octopuses control their infinite degree-of-freedom arms with panache—capabilities typical of nature where the distribution of reflex-like intelligence throughout soft muscular networks greatly outperforms anything hard, heavy, and man-made. Dielectric elastomer actuators show great promise for soft artificial muscle networks. One way to make them smart is with piezo-resistive Dielectric Elastomer Switches (DES) that can be combined with artificial muscles to create arbitrary digital logic circuits. Unfortunately there are currently no reliable materials or fabrication process. Thus devices typically fail within a few thousand cycles. As a first step in the search for better materials we present a preliminary exploration of piezo-resistors made with filtered cathodic vacuum arc metal ion implantation. DES were formed on polydimethylsiloxane silicone membranes out of ion implanted gold nano-clusters. We propose that there are four distinct regimes (high dose, above percolation, on percolation, low dose) in which gold ion implanted piezo-resistors can operate and present experimental results on implanted piezo-resistors switching high voltages as well as a simple artificial muscle inverter. While gold ion implanted DES are limited by high hysteresis and low sensitivity, they already show promise for a range of applications including hysteretic oscillators and soft generators. With improvements to implanter process control the promise of artificial muscle circuitry for soft smart actuator networks could become a reality.

  19. Quantum interference in plasmonic circuits.

    PubMed

    Heeres, Reinier W; Kouwenhoven, Leo P; Zwiller, Valery

    2013-10-01

    Surface plasmon polaritons (plasmons) are a combination of light and a collective oscillation of the free electron plasma at metal/dielectric interfaces. This interaction allows subwavelength confinement of light beyond the diffraction limit inherent to dielectric structures. As a result, the intensity of the electromagnetic field is enhanced, with the possibility to increase the strength of the optical interactions between waveguides, light sources and detectors. Plasmons maintain non-classical photon statistics and preserve entanglement upon transmission through thin, patterned metallic films or weakly confining waveguides. For quantum applications, it is essential that plasmons behave as indistinguishable quantum particles. Here we report on a quantum interference experiment in a nanoscale plasmonic circuit consisting of an on-chip plasmon beamsplitter with integrated superconducting single-photon detectors to allow efficient single plasmon detection. We demonstrate a quantum-mechanical interaction between pairs of indistinguishable surface plasmons by observing Hong-Ou-Mandel (HOM) interference, a hallmark non-classical interference effect that is the basis of linear optics-based quantum computation. Our work shows that it is feasible to shrink quantum optical experiments to the nanoscale and offers a promising route towards subwavelength quantum optical networks. PMID:23934097

  20. Structure for monolithic optical circuits

    NASA Technical Reports Server (NTRS)

    Evanchuk, Vincent L. (Inventor)

    1984-01-01

    A method for making monolithic optical circuits, with related optical devices as required or desired, on a supporting surface (10) consists of coating the supporting surface with reflecting metal or cladding resin, spreading a layer of liquid radiation sensitive plastic (12) on the surface, exposing the liquid plastic with a mask (14) to cure it in a desired pattern of light conductors (16, 18, 20), washing away the unexposed liquid plastic, and coating the conductors thus formed with reflective metal or cladding resin. The index of refraction for the cladding (22) is selected to be lower than for the conductors so that light in the conductors will be reflected by the interface with the cladding. For multiple level conductors, as where one conductor must cross over another, the process may be repeated to fabricate a bridge with columns (24, 26) of conductors to the next level, and conductor (28) between the columns. For more efficient transfer of energy over the bridge, faces at 45.degree. may be formed to reflect light up and across the bridge.