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Sample records for dc wiring system

  1. DC wiring system grounding and ground fault protection issues for central station photovoltaic power plants

    NASA Technical Reports Server (NTRS)

    Simburger, E. J.

    1983-01-01

    The DC wiring system for a photovoltaic power plant presents a number of unique challenges to be overcome by the plant designers. There are a number of different configurations that the grounding of the DC wiring system can take, and the choice will affect the number and type of protective devices required to ensure safety of personnel and protection of equipment. The major grounding and fault protection considerations that must be taken into account when selecting the basic overall circuit configuration are summarized. The inherent advantages and disadvantages of each type of circuit grounding (resistance or solid) along with the personnel safety and equipment protection issues for each of these grounding methods are presented.

  2. New Approaches for Direct Current (DC) Balanced SpaceWire

    NASA Technical Reports Server (NTRS)

    Kisin, Alex; Rakow, Glenn

    2016-01-01

    Direct Current (DC) line balanced SpaceWire is attractive for a number of reasons. Firstly, a DC line balanced interface provides the ability to isolate the physical layer with either a transformer or capacitor to achieve higher common mode voltage rejection and or the complete galvanic isolation in the case of a transformer. And secondly, it provides the possibility to reduce the number of conductors and transceivers in the classical SpaceWire interface by half by eliminating the Strobe line. Depending on the modulator scheme the clock data recovery frequency requirements may be only twice that of the transmit clock, or even match the transmit clock: depending on the Field Programmable Gate Array (FPGA) decoder design. In this paper, several different implementation scenarios will be discussed. Two of these scenarios are backward compatible with the existing SpaceWire hardware standards except for changes at the character level. Three other scenarios, while decreasing by half the standard SpaceWire hardware components, will require changes at both the character and signal levels and work with fixed rates. Other scenarios with variable data rates will require an additional SpaceWire interface handshake initialization sequence.

  3. New Approaches for DC Balanced SpaceWire

    NASA Technical Reports Server (NTRS)

    Kisin, Alex; Rakow, Glenn

    2016-01-01

    Direct Current (DC) line balanced SpaceWire is attractive for a number of reasons. Firstly, a DC line balanced interface provides the ability to isolate the physical layer with either a transformer or capacitor to achieve higher common mode voltage rejection and/or the complete galvanic isolation in the case of a transformer. Secondly, it provides the possibility to reduce the number of conductors and transceivers in the classical SpaceWire interface by half by eliminating the Strobe line. Depending on the modulator scheme - the clock data recovery frequency requirements may be only twice that of the transmit clock, or even match the transmit clock: depending on the Field Programmable Gate Array (FPGA) decoder design. In this paper, several different implementation scenarios will be discussed. Two of these scenarios are backward compatible with the existing SpaceWire hardware standards except for changes at the character level. Three other scenarios, while decreasing by half the standard SpaceWire hardware components, will require changes at both the character and signal levels and work with fixed rates. Other scenarios with variable data rates will require an additional SpaceWire interface handshake initialization sequence.

  4. LANSCE-R WIRE-SCANNER SYSTEM

    SciTech Connect

    Gruchalla, Michael E.

    2011-01-01

    The National Instruments cRIO platform is used for the new LANSCE-R wire-scanner systems. All wire-scanner electronics are integrated into a single BiRa BiRIO 4U cRIO chassis specifically designed for the cRIO crate and all interface electronics. The BiRIO chassis, actuator and LabVIEW VIs provide a complete wire-scanner system integrated with EPICS. The new wire-scanner chassis includes an 8-slot cRIO crate with Virtex-5 LX 110 FPGA and Power-PC real-time controller, the LANL-developed cRIO 2-axis wire-sensor analog interface module (AFE), NI9222 cRIO 4-channel 16-bit digitizer, cRIO resolver demodulator, cRIO event receiver, front-panel touch panel display, motor driver, and all necessary software, interface wiring, connectors and ancillary components. This wirescanner system provides a complete, turn-key, 2-axis wire-scanner system including 2-channel low-noise sensewire interface with variable DC wire bias and wireintegrity monitor, 16-bit signal digitizers, actuator motor drive and control, actuator position sensing, limit-switch interfaces, event receiver, LabVIEW and EPICS interface, and both remote operation and full stand-alone operation using the touch panel.

  5. Robust 300 C wire insulation system

    NASA Technical Reports Server (NTRS)

    Nairus, John G.

    1994-01-01

    The objective of this program is to identify, develop, and demonstrate an optimum wire insulation system that is capable of continuous operation at 300 C. The system is to possess a combination of superior electrical (AC or DC), mechanical, and physical properties over the KAPTON (trademark) derived insulations described in MIL-W-81381 and those hybrid constructions identified in Air Force contract F33615-89-C-5606, commonly known as TKT constructions.

  6. A Prototype Wire Position Monitoring System

    SciTech Connect

    Wang, Wei

    2010-12-07

    The Wire Position Monitoring System (WPM) will track changes in the transverse position of LCLS Beam Position Monitors (BPMs) to 1{micro}m over several weeks. This position information will be used between applications of beam based alignment to correct for changes in component alignment. The WPM system has several requirements. The sensor range must be large enough so that precision sensor positioning is not required. The resolution needs to be small enough so that the signal can be used to monitor motion to 1{micro}m. The system must be stable enough so that system drift does not mimic motion of the component being monitored. The WPM sensor assembly consists of two parts, the magnetic sensor and an integrated lock-in amplifier. The magnetic sensor picks up a signal from the alternating current in a stretched wire. The voltage v induced in the sensor is proportional to the wire displacement from the center of the sensor. The integrated lock-in amplifier provides a DC output whose magnitude is proportional to the AC signal from the magnetic sensor. The DC output is either read on a digital voltmeter or digitized locally and communicated over a computer interface.

  7. 49 CFR 393.28 - Wiring systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.28 Wiring...

  8. SpaceWire Data Handling Demonstration System

    NASA Astrophysics Data System (ADS)

    Mills, S.; Parkes, S. M.; O'Gribin, N.

    2007-08-01

    The SpaceWire standard was published in 2003 with the aim of providing a standard for onboard communications, defining the physical and data link layers of an interconnection, in order to improve reusability, reliability and to reduce the cost of mission development. The many benefits which it provides mean that it has already been used in a number of missions, both in Europe and throughout the world. Recent work by the SpaceWire community has included the development of higher level protocols for SpaceWire, such as the Remote Memory Access Protocol (RMAP) which can be used for many purposes, including the configuration of SpaceWire devices. Although SpaceWire has become very popular, the various ways in which it can be used are still being discovered, as are the most efficient ways to use it. At the same time, some in the space industry are not even aware of SpaceWire's existence. This paper describes the SpaceWire Data Handling Demonstration System that has been developed by the University of Dundee. This system simulates an onboard data handling network based on SpaceWire. It uses RMAP for all communication, and so demonstrates how SpaceWire and standardised higher level protocols can be used onboard a spacecraft. The system is not only a good advert for those who are unfamiliar with the benefits of SpaceWire, it is also a useful tool for those using SpaceWire to test ideas.

  9. A Vibrating Wire System For Quadrupole Fiducialization

    SciTech Connect

    Wolf, Zachary

    2010-12-13

    A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method

  10. Wire-rope emplacement of diagnostics systems

    SciTech Connect

    Burden, W.L.

    1982-05-07

    The study reported here was initiated to determine if, with the Cable Downhole System (CDS) currently under development, there is an advantage to using continuous wire rope to lower the emplacement package to the bottom of the hole. A baseline design using two wire ropes as well as several alternatives are discussed in this report. It was concluded that the advantages of the wire-rope emplacement system do not justify the cost of converting to such a system, especially for LLNL's maximum emplacement package weights.

  11. Comparing conductance quantization in quantum wires and quantum Hall systems

    NASA Astrophysics Data System (ADS)

    Alekseev, Anton Yu.; Cheianov, Vadim V.; Fröhlich, Jürg

    1996-12-01

    We suggest a means to calculate the dc conductance of a one-dimensional electron system described by the Luttinger model. Our approach is based on the ideas of Landauer and Büttiker on transport in ballistic channels and on the methods of current algebra. We analyze in detail the way in which the system can be coupled to external reservoirs. This determines whether the conductance is renormalized or not. We provide a parallel treatment of a quantum wire and a fractional quantum Hall system on a cylinder with two widely separated edges. Although both systems are described by the same effective theory, the physical electrons are identified with different types of excitations, and hence the coupling to external reservoirs is different. As a consequence, the conductance in the wire is quantized in integer units of e2/h per spin orientation whereas the Hall conductance allows for fractional quantization.

  12. Systems Analysis Teaching: The Kengor Wire Company

    ERIC Educational Resources Information Center

    Kennedy, W. J., Jr.; Derrick, L. R.

    1976-01-01

    Describes a group of systems analysis courses which utilizes a computer model of a company which makes house wire to provide a realistic representation of the complexities involved in industrial management. (CP)

  13. In-Situ Wire Damage Detection System

    NASA Technical Reports Server (NTRS)

    Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott

    2012-01-01

    An In-Situ Wire Damage Detection System (ISWDDS) has been developed that is capable of detecting damage to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost core conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for damage detection. A fast-risetime pulse is injected into either the core conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is damaged, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the damage.

  14. Printed wiring board system programmer's manual

    NASA Technical Reports Server (NTRS)

    Brinkerhoff, C. D.

    1973-01-01

    The printed wiring board system provides automated techniques for the design of printed circuit boards and hybrid circuit boards. The system consists of four programs: (1) the preprocessor program combines user supplied data and pre-defined library data to produce the detailed circuit description data; (2) the placement program assigns circuit components to specific areas of the board in a manner that optimizes the total interconnection length of the circuit; (3) the organizer program assigns pin interconnections to specific board levels and determines the optimal order in which the router program should attempt to layout the paths connecting the pins; and (4) the router program determines the wire paths which are to be used to connect each input pin pair on the circuit board. This document is intended to serve as a programmer's reference manual for the printed wiring board system. A detailed description of the internal logic and flow of the printed wiring board programs is included.

  15. Modeling of DC spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Berry, F. C.

    1995-01-01

    Future spacecraft power systems must be capable of supplying power to various loads. This delivery of power may necessitate the use of high-voltage, high-power dc distribution systems to transmit power from the source to the loads. Using state-of-the-art power conditioning electronics such as dc-dc converters, complex series and parallel configurations may be required at the interface between the source and the distribution system and between the loads and the distribution system. This research will use state-variables to model and simulate a dc spacecraft power system. Each component of the dc power system will be treated as a multiport network, and a state model will be written with the port voltages as the inputs. The state model of a component will be solved independently from the other components using its state transition matrix. A state-space averaging method is developed first in general for any dc-dc switching converter, and then demonstrated in detail for the particular case of the boost power stage. General equations for both steady-state (dc) and dynamic effects (ac) are obtained, from which important transfer functions are derived and applied to a special case of the boost power stage.

  16. A FLYING WIRE SYSTEM IN THE AGS.

    SciTech Connect

    HUANG,H.; BUXTON,W.; MAHLER,G.; MARUSIC,A.; ROSER,T.; SMITH,G.; SYPHERS,M.; WILLIAMS,N.; WITKOVER,R.

    1999-03-29

    As the AGS prepares to serve as the injector for RHIC, monitoring and control of the beam transverse emittance become a major and important topic. Before the installation of the flying wire system, the emittance was measured with ionization profile monitors in the AGS, which require correction for space charge effects. It is desirable to have a second means of measuring profile that is less depend on intensity. A flying wire system has been installed in the AGS recently to perform this task. This paper discusses the hardware and software setup and the capabilities of the system.

  17. LANSCE Wire Scanner System Prototype: Switchyard Test

    SciTech Connect

    Sedillo, James D

    2012-04-11

    On November 19, 2011, the beam diagnostics team of Los Alamos National Laboratory's LANSCE accelerator facility conducted a test of a prototype wire scanner system for future deployment within the accelerator's switchyard area. The primary focus of this test was to demonstrate the wire scanner control system's ability to extend its functionality beyond acquiring lower energy linac beam profile measurements to acquiring data in the switchyard. This study summarizes the features and performance characteristics of the electronic and mechanical implementation of this system with details focusing on the test results.

  18. Integrated Electrical Wire Insulation Repair System

    NASA Technical Reports Server (NTRS)

    Williams, Martha; Jolley, Scott; Gibson, Tracy; Parks, Steven

    2013-01-01

    An integrated system tool will allow a technician to easily and quickly repair damaged high-performance electrical wire insulation in the field. Low-melt polyimides have been developed that can be processed into thin films that work well in the repair of damaged polyimide or fluoropolymer insulated electrical wiring. Such thin films can be used in wire insulation repairs by affixing a film of this low-melt polyimide to the damaged wire, and heating the film to effect melting, flow, and cure of the film. The resulting repair is robust, lightweight, and small in volume. The heating of this repair film is accomplished with the use of a common electrical soldering tool that has been modified with a special head or tip that can accommodate the size of wire being repaired. This repair method can furthermore be simplified for the repair technician by providing replaceable or disposable soldering tool heads that have repair film already "loaded" and ready for use. The soldering tool heating device can also be equipped with a battery power supply that will allow its use in areas where plug-in current is not available

  19. dc power system for deuteron accelerator

    SciTech Connect

    Creek, K.O.; Liska, D.J.

    1981-01-01

    The Fusion Materials Irradiation Test (FMIT) Facility dc power system provides excitation current for all linac and High-Energy Beam Transport (HEBT) quadrupole and bending magnets, excitation for horizontal and vertical beam steering, and current-bypass shunts.

  20. A review of wiring system safety in space power systems

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammoud, Ahmad N.

    1993-01-01

    Wiring system failures have resulted from arc propagation in the wiring harnesses of current aerospace vehicles. These failures occur when the insulation becomes conductive upon the initiation of an arc. In some cases, the conductive path of the carbon arc track displays a high enough resistance such that the current is limited, and therefore may be difficult to detect using conventional circuit protection. Often, such wiring failures are not simply the result of insulation failure, but are due to a combination of wiring system factors. Inadequate circuit protection, unforgiving system designs, and careless maintenance procedures can contribute to a wiring system failure. This paper approaches the problem with respect to the overall wiring system, in order to determine what steps can be taken to improve the reliability, maintainability, and safety of space power systems. Power system technologies, system designs, and maintenance procedures which have led to past wiring system failures will be discussed. New technologies, design processes, and management techniques which may lead to improved wiring system safety will be introduced.

  1. USAF/WL robust 300 C wire insulation system program status

    NASA Technical Reports Server (NTRS)

    Wong, Wing

    1995-01-01

    The objective of this program is to identify, develop, and demonstrate an optimum wire insulation system capable of continuous operation at 300 C which possesses a combination of superior electrical (AC or DC), mechanical, and physical properties over Kapton derived insulations described in MIL-W-81381 and those hybrid materials commonly known as TKT constructions.

  2. In-Situ Wire Damage Detection System

    NASA Technical Reports Server (NTRS)

    Williams, Martha K. (Inventor); Roberson, Luke B. (Inventor); Tate, Lanetra C. (Inventor); Smith, Trent M. (Inventor); Gibson, Tracy L. (Inventor); Jolley, Scott T. (Inventor); Medelius, Pedro J. (Inventor)

    2014-01-01

    An in-situ system for detecting damage in an electrically conductive wire. The system includes a substrate at least partially covered by a layer of electrically conductive material forming a continuous or non-continuous electrically conductive layer connected to an electrical signal generator adapted to delivering electrical signals to the electrically conductive layer. Data is received and processed to identify damage to the substrate or electrically conductive layer. The electrically conductive material may include metalized carbon fibers, a thin metal coating, a conductive polymer, carbon nanotubes, metal nanoparticles or a combination thereof.

  3. Evaluation of the intermittent GTA cold wire feed weld system

    SciTech Connect

    Dereskiewicz, J.P.

    1991-08-01

    An intermittent gas tungsten arc cold wire feed process was statistically evaluated to determine the feasibility of applying this process to meet the 0.030-inch weld penetration and peak temperature requirements when unfavorable joint tolerances exist on a subassembly weld. The wire feed system was determined to only slightly benefit the welding process over normal pulsed gas tungsten arc welding using traditional wire feeding capabilities. However, the complexity of this process and extensive welding operator training and qualification does not outweigh the benefits of incorporating this synchronized pulse wire feed system in production. 2 refs., 43 figs., 11 tabs.

  4. Flywheel system using wire-wound rotor

    DOEpatents

    Chiao, Edward Young; Bender, Donald Arthur; Means, Andrew E.; Snyder, Philip K.

    2016-06-07

    A flywheel is described having a rotor constructed of wire wound onto a central form. The wire is prestressed, thus mitigating stresses that occur during operation. In another aspect, the flywheel incorporates a low-loss motor using electrically non-conducting permanent magnets.

  5. The DC-DC conversion power system of the CMS Phase-1 pixel upgrade

    NASA Astrophysics Data System (ADS)

    Feld, L.; Karpinski, W.; Klein, K.; Lipinski, M.; Preuten, M.; Rauch, M.; Schmitz, St.; Wlochal, M.

    2015-01-01

    The pixel detector of the CMS experiment will be exchanged during the year-end technical stop in 2016/2017, as part of the experiment's Phase-1 upgrade. The new device will feature approximately twice the number of readout channels, and consequently the power consumption will be doubled. By moving to a DC-DC conversion powering scheme, it is possible to power the new pixel detector with the existing power supplies and cable plant. The power system of the Phase-1 pixel detector is described and the performance of the new components, including DC-DC converters, DC-DC converter motherboards and various power distribution boards, is detailed. The outcome of system tests in terms of electrical behaviour, thermal management and pixel module performance is discussed.

  6. System and method for evaluating a wire conductor

    DOEpatents

    Panozzo, Edward; Parish, Harold

    2013-10-22

    A method of evaluating an electrically conductive wire segment having an insulated intermediate portion and non-insulated ends includes passing the insulated portion of the wire segment through an electrically conductive brush. According to the method, an electrical potential is established on the brush by a power source. The method also includes determining a value of electrical current that is conducted through the wire segment by the brush when the potential is established on the brush. The method additionally includes comparing the value of electrical current conducted through the wire segment with a predetermined current value to thereby evaluate the wire segment. A system for evaluating an electrically conductive wire segment is also disclosed.

  7. A New Flying Wire System for the Tevatron

    NASA Astrophysics Data System (ADS)

    Blokland, Willem; Dey, Joseph; Vogel, Greg

    1997-05-01

    A new Flying Wires system replaces the old system to enhance the analysis of the beam emittance, improve the reliability, and handle the upcoming upgrades of the Tevatron. New VME data acquisition modules and timing modules allow for more bunches to be sampled more precisely. The programming language LabVIEW, running on a Macintosh computer, controls the VME modules and the nuLogic motion board that flies the wires. LabVIEW also analyzes and stores the data, and handles local and remote commands. The new system flies three wires and fits profiles of 72 bunches to a gaussian function within two seconds. A new console application operates the flying wires from any control console. This paper discusses the hardware and software setup, the capabilities and measurement results of the new Flying Wires system.

  8. Model predictive control of bidirectional isolated DC-DC converter for energy conversion system

    NASA Astrophysics Data System (ADS)

    Akter, Parvez; Uddin, Muslem; Mekhilef, Saad; Tan, Nadia Mei Lin; Akagi, Hirofumi

    2015-08-01

    Model predictive control (MPC) is a powerful and emerging control algorithm in the field of power converters and energy conversion systems. This paper proposes a model predictive algorithm to control the power flow between the high-voltage and low-voltage DC buses of a bidirectional isolated full-bridge DC-DC converter. The predictive control algorithm utilises the discrete nature of the power converters and predicts the future nature of the system, which are compared with the references to calculate the cost function. The switching state that minimises the cost function is selected for firing the converter in the next sampling time period. The proposed MPC bidirectional DC-DC converter is simulated with MATLAB/Simulink and further verified with a 2.5 kW experimental configuration. Both the simulation and experimental results confirm that the proposed MPC algorithm of the DC-DC converter reduces reactive power by avoiding the phase shift between primary and secondary sides of the high-frequency transformer and allow power transfer with unity power factor. Finally, an efficiency comparison is performed between the MPC and dual-phase-shift-based pulse-width modulation controlled DC-DC converter which ensures the effectiveness of the MPC controller.

  9. 49 CFR 393.28 - Wiring systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... Electrical wiring shall be installed and maintained to conform to SAE J1292—Automobile, Truck, Truck-Tractor... conform to SAE J560. The reference to SAE J1292 shall not be construed to require circuit protection...

  10. 49 CFR 393.28 - Wiring systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Electrical wiring shall be installed and maintained to conform to SAE J1292—Automobile, Truck, Truck-Tractor... conform to SAE J560. The reference to SAE J1292 shall not be construed to require circuit protection...

  11. 49 CFR 393.28 - Wiring systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Electrical wiring shall be installed and maintained to conform to SAE J1292—Automobile, Truck, Truck-Tractor... conform to SAE J560. The reference to SAE J1292 shall not be construed to require circuit protection...

  12. 49 CFR 393.28 - Wiring systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Electrical wiring shall be installed and maintained to conform to SAE J1292—Automobile, Truck, Truck-Tractor... conform to SAE J560. The reference to SAE J1292 shall not be construed to require circuit protection...

  13. Plasmon hybridization in parallel nano-wire systems

    SciTech Connect

    Moradi, Afshin

    2011-06-15

    We apply the plasmon hybridization method to a double-nano-wire system, providing a simple and intuitive description of the plasmon excitations in the system. We apply the two-center cylindrical coordinate system for mathematical convenience and find an explicit form of the surface plasmon oscillations, in terms of the interaction between the bare plasmon modes of the individual surfaces of the nano-wires. We present numerical results to display how the plasmon excitations of the system depend on nano-wire separation when there is no angular momentum transfer, i.e., when m = 0.

  14. Simultaneous distribution of AC and DC power

    DOEpatents

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  15. Comparison of solar panel cooling system by using dc brushless fan and dc water

    NASA Astrophysics Data System (ADS)

    Irwan, Y. M.; Leow, W. Z.; Irwanto, M.; M, Fareq; Hassan, S. I. S.; Safwati, I.; Amelia, A. R.

    2015-06-01

    The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.

  16. Electric Field Wire Boom System and instrument for CubeSats

    NASA Astrophysics Data System (ADS)

    Stromberg, E. M.; Burr, S.; Hui, D.; Swenson, C.

    2009-12-01

    The viability of CubeSats as meaningful platforms for observing the upper atmosphere depends upon the development of suitable scientific instrumentation. One of the most fundamental parameters to observe in the space environment is the electric fields which drive the motions of the plasma in the ionosphere and magnetosphere. A well known technique for observing electric fields is the double probe with sensors deployed several meters from the space vehicle. A compact wire boom system, deploying sensors from opposite sides of a spinning CubeSat has been developed at Utah State University. We present the development of a 10 meter tip-to-tip wire boom system to deploy four 1-cm spherical double probe sensors. The wire boom mechanism consists of a spool which is actuated with a small non-magnetic, piezoelectric motor, to control deployment. The wire boom and electric field instrument is 1.25cm high and fits a standard 10 x10 cm CubeSat cross section. The spherical sensors at the end of the wire booms are gold plated to minimize geometric work function dissimilarities and to provide surface electrical stability. We present an analysis of the expected performance and lifetime of this boom in low Earth orbit. The proposed design permits the measurement of the two-dimensional DC-electric field determined only by the spacecraft velocity and the instrument sampling rate.

  17. Beam Position and Phase Monitor - Wire Mapping System

    SciTech Connect

    Watkins, Heath A; Shurter, Robert B.; Gilpatrick, John D.; Kutac, Vincent G.; Martinez, Derwin

    2012-04-10

    The Los Alamos Neutron Science Center (LANSCE) deploys many cylindrical beam position and phase monitors (BPPM) throughout the linac to measure the beam central position, phase and bunched-beam current. Each monitor is calibrated and qualified prior to installation to insure it meets LANSCE requirements. The BPPM wire mapping system is used to map the BPPM electrode offset, sensitivity and higher order coefficients. This system uses a three-axis motion table to position the wire antenna structure within the cavity, simulating the beam excitation of a BPPM at a fundamental frequency of 201.25 MHz. RF signal strength is measured and recorded for the four electrodes as the antenna position is updated. An effort is underway to extend the systems service to the LANSCE facility by replacing obsolete electronic hardware and taking advantage of software enhancements. This paper describes the upgraded wire positioning system's new hardware and software capabilities including its revised antenna structure, motion control interface, RF measurement equipment and Labview software upgrades. The main purpose of the wire mapping system at LANSCE is to characterize the amplitude response versus beam central position of BPPMs before they are installed in the beam line. The wire mapping system is able to simulate a beam using a thin wire and measure the signal response as the wire position is varied within the BPPM aperture.

  18. Aircraft wire system laboratory development : phase I progress report.

    SciTech Connect

    Dinallo, Michael Anthony; Lopez, Christopher D.

    2003-08-01

    An aircraft wire systems laboratory has been developed to support technical maturation of diagnostic technologies being used in the aviation community for detection of faulty attributes of wiring systems. The design and development rationale of the laboratory is based in part on documented findings published by the aviation community. The main resource at the laboratory is a test bed enclosure that is populated with aged and newly assembled wire harnesses that have known defects. This report provides the test bed design and harness selection rationale, harness assembly and defect fabrication procedures, and descriptions of the laboratory for usage by the aviation community.

  19. BAE Systems Radiation Hardened SpaceWire ASIC and Roadmap

    NASA Technical Reports Server (NTRS)

    Berger, Richard; Milliser, Myrna; Kapcio, Paul; Stanley, Dan; Moser, David; Koehler, Jennifer; Rakow, Glenn; Schnurr, Richard

    2006-01-01

    An Application Specific Integrated Circuit (ASIC) that implements the SpaceWire protocol has been developed in a radiation hardened 0.25 micron CMOS, technology. This effort began in March 2003 as a joint development between the NASA Goddard Space Flight Center (GSFC) and BAE Systems. The BAE Systems SpaceWire ASlC is comprised entirely of reusable core elements, many of which are already flight-proven. It incorporates a 4-port SpaceWire router with two local ports, dual PC1 bus interfaces, a microcontroller, 32KB of internal memory, -and a memory controller for additional external memory use. The SpaceWire ASlC is planned for use on both the Geostationary Operational Environmental Satellites (GOES)-R and the Lunar Reconnaissance Orbiter (LRO). Engineering parts have already been delivered to both programs. This paper discusses the SpaceWire protocol and those elements of it that have been built into the current SpaceWire reusable core. There are features within the core that go beyond the current standard that can be enabled or disabled by the user and these will be described. The adaptation of SpaceWire to BAE Systems' On Chip Bus (OCB) for compatibility with the other reusable cores will be discussed. Optional configurations within user systems will be shown. The physical imp!ementation of the design will be described and test results from the hardware will be discussed. Finally, the BAE Systems roadmap for SpaceWire developments will be discussed, including some products already in design as well as longer term plans.

  20. DC isolation and protection system and circuit

    NASA Technical Reports Server (NTRS)

    Wagner, Charles A. (Inventor); Kellogg, Gary V. (Inventor)

    1991-01-01

    A precision analog electronic circuit that is capable of sending accurate signals to an external device that has hostile electric characteristics, including the presence of very large common mode voltages. The circuit is also capable of surviving applications of normal mode overvoltages of up to 120 VAC/VDC for unlimited periods of time without damage or degradation. First, the circuit isolates the DC signal output from the computer. Means are then provided for amplifying the isolated DC signal. Further means are provided for stabilizing and protecting the isolating and amplifying means, and the isolated and amplified DC signal which is output to the external device, against overvoltages and overcurrents.

  1. Differential Power Processing for DC Systems

    SciTech Connect

    Shenoy, PS; Krein, PT

    2013-04-01

    This paper introduces an approach to dc power delivery that reduces power loss by minimizing redundant energy conversion. Existing power distribution techniques tend to increase the number of cascaded conversion stages, which limits overall efficiency. Differential power processing enables independent load regulation, while processing only a small portion of the total load power. Bulk power conversion occurs once. Load voltage domains are connected in series, and differential converters act as controllable current sources to regulate intermediate nodes. This enables independent, low supply voltages, which can reduce system energy consumption, especially in digital circuits and solid-state lighting. Since differential voltage regulators process a fraction of the load power, decreased size, cost, and conversion losses are attainable. Under balanced load conditions, secondary differential converters do not process any power. This paper analyzes several differential power delivery architectures that can be applied to homogenous and heterogeneous loads at various levels: chip, board, blade, etc. A variety of operating conditions for a test system with four series voltage domains are examined in simulation and verified with experimental hardware. Results in a reference application show a 7-8% decrease in input power and 6-7 percentage points increase in overall conversion efficiency as compared to a conventional cascaded approach.

  2. Ferrite insertion at Recycler Flying Wire System

    SciTech Connect

    K.Y. Ng

    2004-02-27

    Ferrite rods are installed inside the flying-wire cavity of the Recycler Ring and at entrance and exit beam pipes in order to absorb high-frequency electromagnetic waves excited by the beam. However, these rods may also deteriorate the vacuum pressure of the ring. An investigation is made to analyze the necessity of the ferrite rods at the entrance and exit beam pipes.

  3. SNS LINAC Wire Scanner System : Signal Levels and Accuracy.

    SciTech Connect

    Plum, M. A.; Christensen, W.; Myer, R. E.; Rose, C. R.

    2002-01-01

    The linac wire scanner system for the Spallation Neutron Source (SNS) at Oak Ridge, TN, USA, calls for 5 units in the medium energy beam transport (MEBT), 5 in the drift tube linac (DTL), and 10 in the coupled cavity linac (CCL). In this paper we present expected signal levels and an analysis of the error in the beam size measurement as functions of wire position and electrical signal errors.

  4. A Laser-Wire System at the ATF Extraction Line

    SciTech Connect

    Boogert, S.T.; Blair, G.; Boorman, G.; Bosco, A.; Deacon, L.; Driouichi, C.; Karataev, P.; Kamps, T.; Delerue, N.; Dixit, S.; Foster, B.; Gannaway, F.; Howell, D.F.; Qureshi, M.; Reichold, A.; Senanayake, R.; Aryshev, A.; Hayano, H.; Kubo, K.; Terunuma, N.; Urakawa, J.; /KEK, Tsukuba /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech. /SLAC

    2007-02-12

    A new laser-wire (LW) system has been installed at the ATF extraction line at KEK, Tsukuba. The system aims at a micron-scale laser spot size and employs a mode-locked laser system. The purpose-built interaction chamber, light delivery optics, and lens systems are described, and the first results are presented.

  5. Operational environments for electrical power wiring on NASA space systems

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammoud, Ahmad N.; Bercaw, Robert W.

    1994-01-01

    Electrical wiring systems are used extensively on NASA space systems for power management and distribution, control and command, and data transmission. The reliability of these systems when exposed to the harsh environments of space is very critical to mission success and crew safety. Failures have been reported both on the ground and in flight due to arc tracking in the wiring harnesses, made possible by insulation degradation. This report was written as part of a NASA Office of Safety and Mission Assurance (Code Q) program to identify and characterize wiring systems in terms of their potential use in aerospace vehicles. The goal of the program is to provide the information and guidance needed to develop and qualify reliable, safe, lightweight wiring systems, which are resistant to arc tracking and suitable for use in space power applications. This report identifies the environments in which NASA spacecraft will operate, and determines the specific NASA testing requirements. A summary of related test programs is also given in this report. This data will be valuable to spacecraft designers in determining the best wiring constructions for the various NASA applications.

  6. Wired.

    ERIC Educational Resources Information Center

    Conklin, Aaron R.

    1998-01-01

    Discusses technology's impact on scoreboard design: the development of the light-emitting diode (LED) display. How the LED system works is explained, as are the advantages and disadvantages of LED compared with incandescent lamp boards. Final comments address deciding on materials for scoreboard casings. (GR)

  7. Risk management in fly-by-wire systems

    NASA Technical Reports Server (NTRS)

    Knoll, Karyn T.

    1993-01-01

    A general description of various types of fly-by-wire systems is provided. The risks inherent in digital flight control systems, like those used in the Space Shuttle, are identified. The results of a literature survey examining risk management methods in use throughout the aerospace industry are presented. The applicability of these methods to the Space Shuttle program is discussed.

  8. dc: a live Webcast control system

    NASA Astrophysics Data System (ADS)

    Yu, Tai-Ping; Wu, David; Mayer-Patel, Ketan D.; Rowe, Lawrence A.

    2000-12-01

    Live Internet streaming media programs, called webcasts, can adopt techniques developed by television to obtain higher quality. We have developed a general webcast production model composed of three stages (i.e., sources, broadcast, and transmission) and a tool, called the Director's Console (dc), to control live webcasts. The tool is one component of a distributed service architecture, which adapts to varying physical infrastructure and broadcast configurations.

  9. Comparison of DC and AC Transport in 1.5-7.5 nm Oligophenylene Imine Molecular Wires across Two Junction Platforms: Eutectic Ga-In versus Conducting Probe Atomic Force Microscope Junctions.

    PubMed

    Sangeeth, C S Suchand; Demissie, Abel T; Yuan, Li; Wang, Tao; Frisbie, C Daniel; Nijhuis, Christian A

    2016-06-15

    We have utilized DC and AC transport measurements to measure the resistance and capacitance of thin films of conjugated oligophenyleneimine (OPI) molecules ranging from 1.5 to 7.5 nm in length. These films were synthesized on Au surfaces utilizing the imine condensation chemistry between terephthalaldehyde and 1,4-benzenediamine. Near edge X-ray absorption fine structure (NEXAFS) spectroscopy yielded molecular tilt angles of 33-43°. To probe DC and AC transport, we employed Au-S-OPI//GaOx/EGaIn junctions having contact areas of 9.6 × 10(2) μm(2) (10(9) nm(2)) and compared to previously reported DC results on the same OPI system obtained using Au-S-OPI//Au conducting probe atomic force microscopy (CP-AFM) junctions with 50 nm(2) areas. We found that intensive observables agreed very well across the two junction platforms. Specifically, the EGaIn-based junctions showed: (i) a crossover from tunneling to hopping transport at molecular lengths near 4 nm; (ii) activated transport for wires >4 nm in length with an activation energy of 0.245 ± 0.008 eV for OPI-7; (iii) exponential dependence of conductance with molecular length with a decay constant β = 2.84 ± 0.18 nm(-1) (DC) and 2.92 ± 0.13 nm(-1) (AC) in the tunneling regime, and an apparent β = 1.01 ± 0.08 nm(-1) (DC) and 0.99 ± 0.11 nm(-1) (AC) in the hopping regime; (iv) previously unreported dielectric constant of 4.3 ± 0.2 along the OPI wires. However, the absolute resistances of Au-S-OPI//GaOx/EGaIn junctions were approximately 100 times higher than the corresponding CP-AFM junctions due to differences in metal-molecule contact resistances between the two platforms. PMID:27172452

  10. New topology for DC/DC bidirectional converter for hybrid systems in renewable energy

    NASA Astrophysics Data System (ADS)

    Lopez, Juan Carlos; Ortega, Manuel; Jurado, Francisco

    2015-03-01

    This article presents a new isolated DC/DC bidirectional converter with soft switching, using a transformer with two voltage taps and two full bridges with insulated-gate bipolar transistors (IGBTs), one on each side of the transformer to be integrated in hybrid systems of renewable energy. A large voltage conversion ratio can be achieved using this converter, in buck and booster modes. Also medium and high DC power can be converted with a good efficiency. Analysis and switching techniques have been reported. To verify the principle of operation, a laboratory prototype of 10 kW has been performed. Experimental results are presented, operating in boost mode. The switching algorithm used has been modelled in MATLAB-Simulink to generate C code. This code has been implemented in a DSP F2812, which has been used to build the prototype.

  11. DC motor proportional control system for orthotic devices

    NASA Technical Reports Server (NTRS)

    Blaise, H. T.; Allen, J. R.

    1972-01-01

    Multi-channel proportional control system for operation of dc motors for use with externally-powered orthotic arm braces is described. Components of circuitry and principles of operation are described. Schematic diagram of control circuit is provided.

  12. Semiautomatic cold wire feeder systems increase GTA productivity

    SciTech Connect

    Richardson, M. )

    1995-01-01

    Often, the focus of attempts to increase GTA welding productivity is on studies to determine if justification exists for additional workstations, or for the investment in new fully automated dedicated welding fixtures. Often less costly and simpler solutions can bring about the necessary means to increase production rates and reduce operating costs. For short-run production applications, it is almost impossible to justify the substantial investment in a dedicated automatic fixture. Now, low cost GTA cold wire feeder systems are within the reach of even small shops. The paper views how cold wire equipment has been applied in several GTAW applications to improve results.

  13. Development of a Production Ready Automated Wire Delivery System

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The current development effort is a Phase 3 research study entitled "A Production Ready Automated Wire Delivery System", contract number NAS8-39933, awarded to Nichols Research Corporation (NRC). The goals of this research study were to production harden the existing Automated Wire Delivery (AWDS) motion and sensor hardware and test the modified AWDS in a range of welding applications. In addition, the prototype AWDS controller would be moved to the VME bus platform by designing, fabricating and testing a single board VME bus AWDS controller. This effort was to provide an AWDS that could transition from the laboratory environment to production operations. The project was performed in two development steps. Step 1 modified and tested an improved MWG. Step 2 developed and tested the AWDS single board VME bus controller. Step 3 installed the Wire Pilot in a Weld Controller with the imbedded VME bus controller.

  14. NASA/BAE SYSTEMS SpaceWire Effort

    NASA Technical Reports Server (NTRS)

    Rakow, Glenn Parker; Schnurr, Richard G.; Kapcio, Paul

    2003-01-01

    This paper discusses the state of the NASA and BAE SYSTEMS developments of SpaceWire. NASA has developed intellectual property that implements SpaceWire in Register Transfer Level (RTL) VHDL for a SpaceWire link and router. This design has been extensively verified using directed tests from the SpaceWire Standard and design specification, as well as being randomly tested to flush out hard to find bugs in the code. The high level features of the design will be discussed, including the support for multiple time code masters, which will be useful for the James Webb Space Telescope electrical architecture. This design is now ready to be targeted to FPGA's and ASICs. Target utilization and performance information will be presented for Spaceflight worthy FPGA's and a discussion of the ASIC implementations will be addressed. In particular, the BAE SYSTEMS ASIC will be highlighted which will be implemented on their .25micron rad-hard line. The chip will implement a 4-port router with the ability to tie chips together to make larger routers without external glue logic. This part will have integrated LVDS drivers/receivers, include a PLL and include skew control logic. It will be targeted to run at greater than 300 MHz and include the implementation for the proposed SpaceWire transport layer. The need to provide a reliable transport mechanism for SpaceWire has been identified by both NASA And ESA, who are attempting to define a transport layer standard that utilizes a low overhead, low latency connection oriented approach that works end-to-end. This layer needs to be implemented in hardware to prevent bottlenecks.

  15. Model-Based Testability Assessment and Directed Troubleshooting of Shuttle Wiring Systems

    NASA Technical Reports Server (NTRS)

    Deb, Somnath; Domagala, Chuck; Shrestha, Roshan; Malepati, Venkatesh; Cavanaugh, Kevin; Patterson-Hine, Ann; Sanderfer, Dwight; Cockrell, Jim; Norvig, Peter (Technical Monitor)

    2000-01-01

    We have recently completed a pilot study on the Space shuttle wiring system commissioned by the Wiring Integrity Research (WIRe) team at NASA Ames Research Center, As the space shuttle ages, it is experiencing wiring degradation problems including arcing, chaffing insulation breakdown and broken conductors. A systematic and comprehensive test process is required to thoroughly test and quality assure (QA) the wiring systems. The NASA WIRe team recognized the value of a formal model based analysis for risk-assessment and fault coverage analysis. However. wiring systems are complex and involve over 50,000 wire segments. Therefore, NASA commissioned this pilot study with Qualtech Systems. Inc. (QSI) to explore means of automatically extracting high fidelity multi-signal models from wiring information database for use with QSI's Testability Engineering and Maintenance System (TEAMS) tool.

  16. Magnetization reversal modes in fourfold Co nano-wire systems

    NASA Astrophysics Data System (ADS)

    Blachowicz, T.; Ehrmann, A.

    2015-09-01

    Magnetic nano-wire systems are, as well as other patterned magnetic structures, of special interest for novel applications, such as magnetic storage media. In these systems, the coupling between neighbouring magnetic units is most important for the magnetization reversal process of the complete system, leading to a variety of magnetization reversal mechanisms. This article examines the influence of the magnetic material on hysteresis loop shape, coercive field, and magnetization reversal modes. While iron nano-wire systems exhibit flat or one-step hysteresis loops, systems consisting of cobalt nano-wires show hysteresis loops with several longitudinal steps and transverse peaks, correlated to a rich spectrum of magnetization reversal mechanisms. We show that changing the material parameters while the system geometry stays identical can lead to completely different hysteresis loops and reversal modes. Thus, especially for finding magnetic nano-systems which can be used as quaternary or even higher-order storage devices, it is rational to test several materials for the planned systems. Apparently, new materials may lead to novel and unexpected behaviour - and can thus result in novel functionalities.

  17. Commissioning a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Levashov, Michael Y

    2010-12-03

    Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of the quadrupoles. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing such a system. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). A previous study investigated the error associated with each step by using a permanent quadrupole magnet on an optical mover system. The study reported an error of 11{micro}m for step 1 and a repeatability of 4{micro}m for step 2. However, the set up used a FARO arm to measure tooling balls and didn't allow to accurately check step 2 for errors; an uncertainty of 100{micro}m was reported. Therefore, even though the repeatability was good, there was no way to check that the error in step 2 was small. Following the recommendations of

  18. Angular Dependence of Transport AC Losses in Superconducting Wire with Position-Dependent Critical Current Density in a DC Magnetic Field

    NASA Astrophysics Data System (ADS)

    Su, Xing-liang; Xiong, Li-ting; Gao, Yuan-wen; Zhou, You-he

    2013-07-01

    Transport AC losses play a very important role in high temperature superconductors (HTSs), which usually carry AC transport current under applied magnetic field in typical application-like conditions. In this paper, we propose the analytical formula for transport AC losses in HTS wire by considering critical current density of both inhomogeneous and anisotropic field dependent. The angular dependence of critical current density is described by effective mass theory, and the HTS wire has inhomogeneous distribution cross-section of critical current density. We calculate the angular dependence of normalized AC losses under different DC applied magnetic fields. The numerical results of this formula agree well with the experiment data and are better than the results of Norris formula. This analytical formula can explain the deviation of experimental transport current losses from the Norris formula and apply to calculate transport AC losses in realistic practical condition.

  19. Photovoltaic-wind hybrid system for permanent magnet DC motor

    NASA Astrophysics Data System (ADS)

    Nasir, M. N. M.; Lada, M. Y.; Baharom, M. F.; Jaafar, H. I.; Ramani, A. N.; Sulaima, M. F.

    2015-05-01

    Hybrid system of Photovoltaic (PV) - Wind turbine (WT) generation has more advantages and reliable compared to PV or wind turbine system alone. The aim of this paper is to model and design hybrid system of PV-WT supplying 100W permanent-magnet dc motor. To achieve the objective, both of PV and WT are connected to converter in order to get the same source of DC supply. Then both sources were combined and straightly connected to 100W permanent magnet dc motor. All the works in this paper is only applied in circuit simulator by using Matlab Simulink. The output produced from each converter is expected to be suit to the motor specification. The output produced from each renewable energy system is as expected to be high as it can support the motor if one of them is breakdown

  20. Fly-by-Wire Systems Enable Safer, More Efficient Flight

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Using the ultra-reliable Apollo Guidance Computer that enabled the Apollo Moon missions, Dryden Flight Research Center engineers, in partnership with industry leaders such as Cambridge, Massachusetts-based Draper Laboratory, demonstrated that digital computers could be used to fly aircraft. Digital fly-by-wire systems have since been incorporated into large airliners, military jets, revolutionary new aircraft, and even cars and submarines.

  1. A framework for SFC/DC system data analysis

    NASA Technical Reports Server (NTRS)

    Centeno, Martha A.

    1993-01-01

    The Shop Floor Control/Data Collection (SFC/DC) system is one of four major modules of the Integrated Work Control System being implemented at the NASA Kennedy Space Center. The SFC/DC system, which has been in operation approximately one and a half years, collects detailed information regarding the duration of tasks as well as work stoppages duration. This information needs to be effectively analyzed, so as be able to manage the shuttle processing activities under the continuous improvement philosophy. We have studied the contents and form of the SFC/DC database, and based on the results of such study, we have designed a Shop floor Modeling, Analysis, and Reporting Tool (SMART). SMART is a collection of compatible tools (off-the-shelf as well as customized C-based tools) that work cohesively to prepare inputs for the analysis models and process the various models. The feasibility of SMART has been demonstrated through an initial prototype.

  2. A Testing System for Diagnosing Misconceptions in DC Electric Circuits.

    ERIC Educational Resources Information Center

    Chang, Kuo-En; Liu, Sei-Hua; Chen, Sei-Wang

    1998-01-01

    Outlines a test-based diagnosis system for misconceptions in DC electric circuits and its three parts: problem library, problem selector and diagnoser. Discusses misconception discrimination and diagnosis theories, and reports the system supports satisfactory diagnosis. Includes an analysis of nine student misconceptions about electrical circuits…

  3. Electrohydrodynamic force produced by a wire-to-cylinder dc corona discharge in air at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Moreau, Eric; Benard, Nicolas; Lan-Sun-Luk, Jean-Daniel; Chabriat, Jean-Pierre

    2013-11-01

    Wire-to-cylinder corona discharges are studied to better understand the electrohydrodynamic (EHD) phenomena that govern the performances of electric propulsion systems. First, theory associated with EHD thrusters is presented in order to be compared with experimental results. Secondly, direct thrust measurements are carried out to optimize the electrical and geometrical parameters of such devices. The main results are as follows: (1) the discharge current I is proportional to the square root of the grounded electrode diameter and to 1/d2 where d is the electrode gap; (2) for d ⩽ 20 mm, the mobility of negative ions is higher than that of positive ions while the mobility of both ions is equal for higher gaps; (3) therefore, for gap ⩾30 mm, positive and negative coronas results in the same current-to-thrust conversion; (4) the current-to-thrust conversion is equal to 33 N A-1 per centimetre of gap, and it is proportional to the gap; (5) the thruster effectiveness θ increases with \\sqrt d , decreases with the square root of thrust and reaches about 15 N kW-1 for d = 40 mm (6) the force computed from experimental velocity profiles is overestimated compared with the values measured with a balance, showing that this method cannot be used for thrust determination.

  4. Flat-top system of the DC-280 cyclotron

    NASA Astrophysics Data System (ADS)

    Gulbekyan, G. G.; Buzmakov, V. A.; Zarubin, V. B.; Ivanenko, I. A.; Kazarinov, N. Yu.; Karamysheva, G. A.; Franko, I.

    2013-07-01

    The flat-top cavity of the radio-frequency accelerating system designed at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, for the DC-280 cyclotron is described. The cyclotron is intended for increasing the capabilities and efficiency of experiments on the synthesis of super-heavy elements and an investigation of their nuclear physical and chemical properties. The DC-280 isochronous heavy-ion cyclotron will produce accelerated beam of ions in the range from neon to uranium. The parameters, design, and results of the experimental and 3D computer modeling of the flat-top cavity of the RF accelerating system of the DC-280 cyclotron are reported.

  5. Operating characteristic analysis of a 400 mH class HTS DC reactor in connection with a laboratory scale LCC type HVDC system

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Kyu; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Lee, Sangjin

    2015-11-01

    High temperature superconducting (HTS) devices are being developed due to their advantages. Most line commutated converter based high voltage direct current (HVDC) transmission systems for long-distance transmission require large inductance of DC reactor; however, generally, copper-based reactors cause a lot of electrical losses during the system operation. This is driving researchers to develop a new type of DC reactor using HTS wire. The authors have developed a 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC system and applied the HTS DC reactor to the HVDC system to investigate their operating characteristics. The 400 mH class HTS DC reactor is designed using a toroid type magnet. The HVDC system is designed in the form of a mono-pole system with thyristor-based 12-pulse power converters. In this paper, the investigation results of the HTS DC reactor in connection with the HVDC system are described. The operating characteristics of the HTS DC reactor are analyzed under various operating conditions of the system. Through the results, applicability of an HTS DC reactor in an HVDC system is discussed in detail.

  6. AC/DC Power Systems with Applications for future Lunar/Mars base and Crew Exploration Vehicle

    NASA Technical Reports Server (NTRS)

    Chowdhury, Badrul H.

    2005-01-01

    ABSTRACT The Power Systems branch at JSC faces a number of complex issues as it readies itself for the President's initiative on future space exploration beyond low earth orbit. Some of these preliminary issues - those dealing with electric power generation and distribution on board Mars-bound vehicle and that on Lunar and Martian surface may be summarized as follows: Type of prime mover - Because solar power may not be readily available on parts of the Lunar/Mars surface and also during the long duration flight to Mars, the primary source of power will most likely be nuclear power (Uranium fuel rods) with a secondary source of fuel cell (Hydrogen supply). The electric power generation source - With nuclear power being the main prime mover, the electric power generation source will most likely be an ac generator at a yet to be determined frequency. Thus, a critical issue is whether the generator should generate at constant or variable frequency. This will decide what type of generator to use - whether it is a synchronous machine, an asynchronous induction machine or a switched reluctance machine. The type of power distribution system - the distribution frequency, number of wires (3- wire, 4-wire or higher), and ac/dc hybridization. Building redundancy and fault tolerance in the generation and distribution sub-systems so that the system is safe; provides 100% availability to critical loads; continues to operate even with faulted sub-systems; and requires minimal maintenance. This report descril_es results of a summer faculty fellowship spent in the Power Systems Branch with the specific aim of investigating some of the lessons learned in electric power generation and usage from the terrestrial power systems industry, the aerospace industry as well as NASA's on-going missions so as to recommend novel surface and vehicle-based power systems architectures in support of future space exploration initiatives. A hybrid ac/dc architecture with source side and load side

  7. Carbon-atom wires: 1-D systems with tunable properties.

    PubMed

    Casari, C S; Tommasini, M; Tykwinski, R R; Milani, A

    2016-02-28

    This review provides a discussion of the current state of research on linear carbon structures and related materials based on sp-hybridization of carbon atoms (polyynes and cumulenes). We show that such systems have widely tunable properties and thus represent an intriguing and mostly unexplored field for both fundamental and applied sciences. We discuss the rich interplay between the structural, vibrational, and electronic properties focusing on recent advances and the future perspectives of carbon-atom wires and novel hybrid sp-sp(2)-carbon architectures. PMID:26847474

  8. Polariton dispersion of a quantum wire superlattice system

    SciTech Connect

    Wilson, K. S. Joseph; Revathy, V.; Amalanathan, M.; Lenin, S. Maria

    2015-06-24

    Superlattices have drawn considerable attention in the recent years. In this work, the behaviour of polaritons in a quantum wire superlattice is analysed both at the brillouin zone edge and at centre of the brillouin zone using LiNbO3/ LiTaO3 as an example. The significance of the polariton modes in both the cases are analysed. New modes on the polaritonic gap, where the propagation of electromagnetic wave is forbidden, is obtained in the system as suggested by some recent literature. The effect on nonlinear interactions of phonon polaritons in LiNbO3/ LiTaO3 superlattices is also discussed.

  9. Polariton dispersion of a quantum wire superlattice system

    NASA Astrophysics Data System (ADS)

    Wilson, K. S. Joseph; Amalanathan, M.; Revathy, V.; Lenin, S. Maria

    2015-06-01

    Superlattices have drawn considerable attention in the recent years. In this work, the behaviour of polaritons in a quantum wire superlattice is analysed both at the brillouin zone edge and at centre of the brillouin zone using LiNbO3/ LiTaO3 as an example. The significance of the polariton modes in both the cases are analysed. New modes on the polaritonic gap, where the propagation of electromagnetic wave is forbidden, is obtained in the system as suggested by some recent literature. The effect on nonlinear interactions of phonon polaritons in LiNbO3/ LiTaO3 superlattices is also discussed.

  10. Carbon-atom wires: 1-D systems with tunable properties

    NASA Astrophysics Data System (ADS)

    Casari, C. S.; Tommasini, M.; Tykwinski, R. R.; Milani, A.

    2016-02-01

    This review provides a discussion of the current state of research on linear carbon structures and related materials based on sp-hybridization of carbon atoms (polyynes and cumulenes). We show that such systems have widely tunable properties and thus represent an intriguing and mostly unexplored field for both fundamental and applied sciences. We discuss the rich interplay between the structural, vibrational, and electronic properties focusing on recent advances and the future perspectives of carbon-atom wires and novel hybrid sp-sp2-carbon architectures.

  11. System For Characterizing Three-Phase Brushless dc Motors

    NASA Technical Reports Server (NTRS)

    Howard, David E.; Smith, Dennis A.

    1996-01-01

    System of electronic hardware and software developed to automate measurements and calculations needed to characterize electromechanical performances of three-phase brushless dc motors, associated shaft-angle sensors needed for commutation, and associated brushless tachometers. System quickly takes measurements on all three phases of motor, tachometer, and shaft-angle sensor simultaneously and processes measurements into performance data. Also useful in development and testing of motors with not only three phases but also two, four, or more phases.

  12. DC link stabilized field oriented control of electric propulsion systems

    SciTech Connect

    Sudhoff, S.D.; Corzine, K.A.; Glover, S.F.; Hegner, H.J.; Robey, H.N. Jr.

    1998-03-01

    Induction motor based electric propulsion systems can be used in a wide variety of applications including locomotives, hybrid electric vehicles, and ships. Field oriented control of these drives is attractive since it allows the torque to be tightly and nearly instantaneously controlled. However, such systems can be prone to negative impedance instability of the DC link. This paper examines this type of instability and sets forth a readily implemented albeit nonlinear control strategy to mitigate this potential problem.

  13. CydDC-mediated reductant export in Escherichia coli controls the transcriptional wiring of energy metabolism and combats nitrosative stress

    PubMed Central

    Holyoake, Louise V.; Hunt, Stuart; Sanguinetti, Guido; Cook, Gregory M.; Howard, Mark J.; Rowe, Michelle L.; Poole, Robert K.; Shepherd, Mark

    2015-01-01

    The glutathione/cysteine exporter CydDC maintains redox balance in Escherichia coli. A cydD mutant strain was used to probe the influence of CydDC upon reduced thiol export, gene expression, metabolic perturbations, intracellular pH homoeostasis and tolerance to nitric oxide (NO). Loss of CydDC was found to decrease extracytoplasmic thiol levels, whereas overexpression diminished the cytoplasmic thiol content. Transcriptomic analysis revealed a dramatic up-regulation of protein chaperones, protein degradation (via phenylpropionate/phenylacetate catabolism), β-oxidation of fatty acids and genes involved in nitrate/nitrite reduction. 1H NMR metabolomics revealed elevated methionine and betaine and diminished acetate and NAD+ in cydD cells, which was consistent with the transcriptomics-based metabolic model. The growth rate and ΔpH, however, were unaffected, although the cydD strain did exhibit sensitivity to the NO-releasing compound NOC-12. These observations are consistent with the hypothesis that the loss of CydDC-mediated reductant export promotes protein misfolding, adaptations to energy metabolism and sensitivity to NO. The addition of both glutathione and cysteine to the medium was found to complement the loss of bd-type cytochrome synthesis in a cydD strain (a key component of the pleiotropic cydDC phenotype), providing the first direct evidence that CydDC substrates are able to restore the correct assembly of this respiratory oxidase. These data provide an insight into the metabolic flexibility of E. coli, highlight the importance of bacterial redox homoeostasis during nitrosative stress, and report for the first time the ability of periplasmic low molecular weight thiols to restore haem incorporation into a cytochrome complex. PMID:26699904

  14. CydDC-mediated reductant export in Escherichia coli controls the transcriptional wiring of energy metabolism and combats nitrosative stress.

    PubMed

    Holyoake, Louise V; Hunt, Stuart; Sanguinetti, Guido; Cook, Gregory M; Howard, Mark J; Rowe, Michelle L; Poole, Robert K; Shepherd, Mark

    2016-03-15

    The glutathione/cysteine exporter CydDC maintains redox balance in Escherichia coli. A cydD mutant strain was used to probe the influence of CydDC upon reduced thiol export, gene expression, metabolic perturbations, intracellular pH homoeostasis and tolerance to nitric oxide (NO). Loss of CydDC was found to decrease extracytoplasmic thiol levels, whereas overexpression diminished the cytoplasmic thiol content. Transcriptomic analysis revealed a dramatic up-regulation of protein chaperones, protein degradation (via phenylpropionate/phenylacetate catabolism), β-oxidation of fatty acids and genes involved in nitrate/nitrite reduction. (1)H NMR metabolomics revealed elevated methionine and betaine and diminished acetate and NAD(+) in cydD cells, which was consistent with the transcriptomics-based metabolic model. The growth rate and ΔpH, however, were unaffected, although the cydD strain did exhibit sensitivity to the NO-releasing compound NOC-12. These observations are consistent with the hypothesis that the loss of CydDC-mediated reductant export promotes protein misfolding, adaptations to energy metabolism and sensitivity to NO. The addition of both glutathione and cysteine to the medium was found to complement the loss of bd-type cytochrome synthesis in a cydD strain (a key component of the pleiotropic cydDC phenotype), providing the first direct evidence that CydDC substrates are able to restore the correct assembly of this respiratory oxidase. These data provide an insight into the metabolic flexibility of E. coli, highlight the importance of bacterial redox homoeostasis during nitrosative stress, and report for the first time the ability of periplasmic low molecular weight thiols to restore haem incorporation into a cytochrome complex. PMID:26699904

  15. Novel Calibration System with Sparse Wires for CMB Polarization Receivers

    NASA Astrophysics Data System (ADS)

    Tajima, O.; Nguyen, H.; Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.

    2012-06-01

    A curl competent (also known as B-modes) in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate "simultaneously" all detectors on the large focal plane. We developed a novel calibration system that rotates a large "sparse" grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature photons from the wire surface. Since the detector has a finite beam size, the observed signal is convolved with the beam property. The intensity of the of the calibrator is reasonable (a few Kelvin or less) compared to sky temperature for typical observing conditions (˜10 K). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

  16. Novel calibration system with sparse wires for CMB polarization receivers

    SciTech Connect

    Tajima, O.; Nguyen, H.; Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A. /Chicago U., KICP

    2011-07-01

    B-modes in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate 'simultaneously' all detectors on the large focal plane. We developed a novel calibration system that rotates a large 'sparse' grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature from the wire surface. Since the detector has a finite beam size, the observed signal is smeared according to the beam property. The resulting smeared polarized radiation has a reasonable intensity (a few Kelvin or less) compared to the sky temperature ({approx}10 K observing condition). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

  17. A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

    SciTech Connect

    Michnoff R.; Biscardi, C.; Cerniglia, P.; Degen, C.; Gassner, D.; Hoff, L.; Hulsart, R.

    2012-04-15

    A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scanner assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.

  18. Output feedback trajectory stabilization of the uncertainty DC servomechanism system.

    PubMed

    Aguilar-Ibañez, Carlos; Garrido-Moctezuma, Ruben; Davila, Jorge

    2012-11-01

    This work proposes a solution for the output feedback trajectory-tracking problem in the case of an uncertain DC servomechanism system. The system consists of a pendulum actuated by a DC motor and subject to a time-varying bounded disturbance. The control law consists of a Proportional Derivative controller and an uncertain estimator that allows compensating the effects of the unknown bounded perturbation. Because the motor velocity state is not available from measurements, a second-order sliding-mode observer permits the estimation of this variable in finite time. This last feature allows applying the Separation Principle. The convergence analysis is carried out by means of the Lyapunov method. Results obtained from numerical simulations and experiments in a laboratory prototype show the performance of the closed loop system. PMID:22884179

  19. Yielding of the clamped-wire system in the Ilizarov external fixator.

    PubMed

    Watson, M A; Matthias, K J; Maffulli, N; Hukins, D W L

    2003-01-01

    This study demonstrates that the clamped-wire system used to suspend bones within an Ilizarov external fixator yields when the perpendicular load exceeds 50 N per wire. Cyclic loading was applied to tensioned wires clamped within an Ilizarov ring component, with steadily increasing load amplitude. Wires were tested at four initial tension settings. The amount of energy lost within the clamped-wire system per load cycle was calculated for every test. The results showed that there was a consistent trend to increasing non-recoverable energy loss per load cycle when peak loads exceed 50 N for all initial tension settings. A finite element (FE) model replicating the experimental conditions was performed to investigate the levels of stress within the loaded wires. The FE model analyses showed that high stresses were generated in the wires close to the clamping sites, and that the stress levels could reasonably be expected to exceed the material yield stress when loaded to about 55 N, for all initial tension settings. The results show that material yield, accompanied by some wire slippage through the clamps, is responsible for system yield, in agreement with previous studies. Although the initial wire tension has an appreciable effect on the wire stiffness, it did not affect the elastic load range of the clamped-wire system. To prevent yield of the clamped-wire system in practice, the fixator should be assembled with sufficient wires to ensure that the load transmitted to each wire by the patient does not exceed 50 N. PMID:14558649

  20. Electrostatic coalescence system with independent AC and DC hydrophilic electrodes

    DOEpatents

    Hovarongkura, A. David; Henry, Jr., Joseph D.

    1981-01-01

    An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

  1. Multi-kw dc power distribution system study program

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.; Krausz, A.

    1974-01-01

    The first phase of the Multi-kw dc Power Distribution Technology Program is reported and involves the test and evaluation of a technology breadboard in a specifically designed test facility according to design concepts developed in a previous study on space vehicle electrical power processing, distribution, and control. The static and dynamic performance, fault isolation, reliability, electromagnetic interference characterisitics, and operability factors of high distribution systems were studied in order to gain a technology base for the use of high voltage dc systems in future aerospace vehicles. Detailed technical descriptions are presented and include data for the following: (1) dynamic interactions due to operation of solid state and electromechanical switchgear; (2) multiplexed and computer controlled supervision and checkout methods; (3) pulse width modulator design; and (4) cable design factors.

  2. NASA/Ames Research Center DC-8 data system

    NASA Technical Reports Server (NTRS)

    Cherniss, S. C.; Scofield, C. P.

    1991-01-01

    In-flight facility data acquisition, distribution, and recording on the NASA Ames Research Center (ARC) DC-8 are performed by the Data Acquisition and Distribution System (DADS). Navigational and environmental data collected by the DADS are converted to engineering units and distributed real-time to investigator stations once per second. Selected engineering units data are printed and displayed on closed circuit television monitors throughout flights. An in-flight graphical display of the DC-8 flight track (with barbs indicating wind direction and magnitude) has recently been added to the DADS capabilities. Logging of data run starts/stops and commentary from the mission director are also provided. All data are recorded to hard disk in-flight and archived to tape medium post-flight. Post-flight, hard copies of the track map and mission director's log are created by the DADS. The DADS is a distributed system consisting of a data subsystem, an Avionic Serial Data-to-VMEbus (ASD2VME) subsystem, and a host subsystem. Each subsystem has a dedicated central processing unit (CPU) and is capable of stand-alone operation. All three subsystems are housed in a single 20-slot VME chassis and communicate with each other over the VMEbus. The data and host subsystems are briefly discussed, and the DC-8 DADS internal configuration and system block diagram are presented.

  3. Modelling, Simulation and Construction of a DC/DC Boost Power Converter: A School Experimental System

    ERIC Educational Resources Information Center

    Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernandez-Guzman, V. M.; Saldana-Gonzalez, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders…

  4. CSMP (Continuous System Modeling Program) modeling of brushless DC motors

    NASA Astrophysics Data System (ADS)

    Thomas, S. M.

    1984-09-01

    Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high horsepower DC motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use in flight control actuators for tactical missiles. This thesis develops a low-order mathematical model for the simulation and analysis of brushless DC motor performance. This model is implemented in CSMP language. It is used to predict such motor performance curves as speed, current and power versus torque. Electronic commutation based on Hall effect sensor positional feedback is simulated. Steady state motor behavior is studied under both constant and variable air gap flux conditions. The variable flux takes two different forms. In the first case, the flux is varied as a simple sinusoid. In the second case, the flux is varied as the sum of a sinusoid and one of its harmonics.

  5. 30 CFR 77.704-11 - Use of grounded messenger wires; ungrounded systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AREAS OF UNDERGROUND COAL MINES Grounding § 77.704-11 Use of grounded messenger wires; ungrounded systems. Solely for purposes of grounding ungrounded high-voltage power systems, grounded messenger wires used to suspend the cables of such systems may be used as a grounding medium....

  6. 30 CFR 77.704-11 - Use of grounded messenger wires; ungrounded systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AREAS OF UNDERGROUND COAL MINES Grounding § 77.704-11 Use of grounded messenger wires; ungrounded systems. Solely for purposes of grounding ungrounded high-voltage power systems, grounded messenger wires used to suspend the cables of such systems may be used as a grounding medium....

  7. 30 CFR 75.902-2 - Approved ground check systems not employing pilot check wires.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved ground check systems not employing... Low- and Medium-Voltage Alternating Current Circuits § 75.902-2 Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot check wires will be approved only...

  8. Model-based testability assessment and directed troubleshooting of shuttle wiring systems

    NASA Astrophysics Data System (ADS)

    Deb, Somnath; Domagala, Chuck; Shrestha, Roshan; Malepati, Venkatesh N.; Cavanaugh, Kevin F.; Patterson-Hine, Ann; Sanderfer, Dwight; Cockrell, Jim

    2001-07-01

    As the space shuttle ages, it is experiencing wiring degradation problems, including arcing, chaffing, insulation breakdown and broken conductors. A systematic and comprehensive test process is required to thoroughly test and QA the wiring systems. The NASA Wiring Integrity Reseach (WIRe) team recognized the value of a formal model based analysis for risk assessment and fault coverage analysis using our TEAMS toolset and commissioned a pilot study with QSI to explore means of automatically extracting high fidelity multisignal models from wiring information databases. The MEC1 Shuttle subsystem was the subject of this study. The connectivity and wiring information for the model was extracted from a Shuttle Connector Analysis Network (SCAN) electronic wirelist. Using this wirelist, QSI concurrently created manual and automatically generated wiring models for all wire paths associated with connector J3 on the MEC1 assembly. The manually generated model helped establish the rules of modeling. The complete MEC1 model was automatically generated based on these rules, thus saving significant modeling cost. The methodology is easily extensible to the entire shuttle wiring system. This paper presents our modeling and analysis results from the pilot study along with our proposed solutions to the complex issues of wiring integrity assessment problem.

  9. DC Bus Regulation with a Flywheel Energy Storage System

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Kascak, Peter E.

    2003-01-01

    This paper describes the DC bus regulation control algorithm for the NASA flywheel energy storage system during charge, charge reduction and discharge modes of operation. The algorithm was experimentally verified with results given in a previous paper. This paper presents the necessary models for simulation with detailed block diagrams of the controller algorithm. It is shown that the flywheel system and the controller can be modeled in three levels of detail depending on the type of analysis required. The three models are explained and then compared using simulation results.

  10. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Electrical wiring interconnection systems (EWIS) maintenance program. 121.1111 Section 121.1111 Aeronautics and Space FEDERAL AVIATION... Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems (EWIS)...

  11. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Electrical wiring interconnection systems (EWIS) maintenance program. 121.1111 Section 121.1111 Aeronautics and Space FEDERAL AVIATION... Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems (EWIS)...

  12. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Electrical wiring interconnection systems (EWIS) maintenance program. 121.1111 Section 121.1111 Aeronautics and Space FEDERAL AVIATION... Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems (EWIS)...

  13. Multi-KW dc distribution system technology research study

    NASA Technical Reports Server (NTRS)

    Dawson, S. G.

    1978-01-01

    The Multi-KW DC Distribution System Technology Research Study is the third phase of the NASA/MSFC study program. The purpose of this contract was to complete the design of the integrated technology test facility, provide test planning, support test operations and evaluate test results. The subjet of this study is a continuation of this contract. The purpose of this continuation is to study and analyze high voltage system safety, to determine optimum voltage levels versus power, to identify power distribution system components which require development for higher voltage systems and finally to determine what modifications must be made to the Power Distribution System Simulator (PDSS) to demonstrate 300 Vdc distribution capability.

  14. Efficient Design in a DC to DC Converter Unit

    NASA Technical Reports Server (NTRS)

    Bruemmer, Joel E.; Williams, Fitch R.; Schmitz, Gregory V.

    2002-01-01

    Space Flight hardware requires high power conversion efficiencies due to limited power availability and weight penalties of cooling systems. The International Space Station (ISS) Electric Power System (EPS) DC-DC Converter Unit (DDCU) power converter is no exception. This paper explores the design methods and tradeoffs that were utilized to accomplish high efficiency in the DDCU. An isolating DC to DC converter was selected for the ISS power system because of requirements for separate primary and secondary grounds and for a well-regulated secondary output voltage derived from a widely varying input voltage. A flyback-current-fed push-pull topology or improved Weinberg circuit was chosen for this converter because of its potential for high efficiency and reliability. To enhance efficiency, a non-dissipative snubber circuit for the very-low-Rds-on Field Effect Transistors (FETs) was utilized, redistributing the energy that could be wasted during the switching cycle of the power FETs. A unique, low-impedance connection system was utilized to improve contact resistance over a bolted connection. For improved consistency in performance and to lower internal wiring inductance and losses a planar bus system is employed. All of these choices contributed to the design of a 6.25 KW regulated dc to dc converter that is 95 percent efficient. The methodology used in the design of this DC to DC Converter Unit may be directly applicable to other systems that require a conservative approach to efficient power conversion and distribution.

  15. Development of a DC propulsion system for an electric vehicle

    NASA Technical Reports Server (NTRS)

    Kelledes, W. L.

    1984-01-01

    The suitability of the Eaton automatically shifted mechanical transaxle concept for use in a near-term dc powered electric vehicle is evaluated. A prototype dc propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the contractor's site. The system consisted of a two-axis, three-speed, automatically-shifted mechanical transaxle, 15.2 Kw rated, separately excited traction motor, and a transistorized motor controller with a single chopper providing limited armature current below motor base speed and full range field control above base speed at up to twice rated motor current. The controller utilized a microprocessor to perform motor and vehicle speed monitoring and shift sequencing by means of solenoids applying hydraulic pressure to the transaxle clutches. Bench dynamometer and track testing was performed. Track testing showed best system efficiency for steady-state cruising speeds of 65-80 Km/Hz (40-50 mph). Test results include acceleration, steady speed and SAE J227A/D cycle energy consumption, braking tests and coast down to characterize the vehicle road load.

  16. X-wing fly-by-wire vehicle management system

    NASA Technical Reports Server (NTRS)

    Fischer, Jr., William C. (Inventor)

    1990-01-01

    A complete, computer based, vehicle management system (VMS) for X-Wing aircraft using digital fly-by-wire technology controlling many subsystems and providing functions beyond the classical aircraft flight control system. The vehicle management system receives input signals from a multiplicity of sensors and provides commands to a large number of actuators controlling many subsystems. The VMS includes--segregating flight critical and mission critical factors and providing a greater level of back-up or redundancy for the former; centralizing the computation of functions utilized by several subsystems (e.g. air data, rotor speed, etc.); integrating the control of the flight control functions, the compressor control, the rotor conversion control, vibration alleviation by higher harmonic control, engine power anticipation and self-test, all in the same flight control computer (FCC) hardware units. The VMS uses equivalent redundancy techniques to attain quadruple equivalency levels; includes alternate modes of operation and recovery means to back-up any functions which fail; and uses back-up control software for software redundancy.

  17. Virtual Instrument Systems in Reality (VISIR) for Remote Wiring and Measurement of Electronic Circuits on Breadboard

    ERIC Educational Resources Information Center

    Tawfik, M.; Sancristobal, E.; Martin, S.; Gil, R.; Diaz, G.; Colmenar, A.; Peire, J.; Castro, M.; Nilsson, K.; Zackrisson, J.; Hakansson, L.; Gustavsson, I.

    2013-01-01

    This paper reports on a state-of-the-art remote laboratory project called Virtual Instrument Systems in Reality (VISIR). VISIR allows wiring and measuring of electronic circuits remotely on a virtual workbench that replicates physical circuit breadboards. The wiring mechanism is developed by means of a relay switching matrix connected to a PCI…

  18. Toward a Reduced-Wire Readout System for Ultrasound Imaging

    PubMed Central

    Lim, Jaemyung; Arkan, Evren F.; Degertekin, F. Levent; Ghovanloo, Maysam

    2015-01-01

    We present a system-on-a-chip (SoC) for use in high-frequency capacitive micromachined ultrasonic transducer (CMUT) imaging systems. This SoC consists of trans-impedance amplifiers (TIA), delay locked loop (DLL) based clock multiplier, quadrature sampler, and pulse width modulator (PWM). The SoC down converts RF echo signal to baseband by quadrature sampling which facilitates modulation. To send data through a 1.6 m wire in the catheter which has limited bandwidth and is vulnerable to noise, the SoC creates a pseudo-digital PWM signal which can be used for back telemetry or wireless readout of the RF data. In this implementation, using a 0.35-μm std. CMOS process, the TIA and single-to-differential (STD) converter had 45 MHz bandwidth, the quadrature sampler had 10.1 dB conversion gain, and the PWM had 5-bit ENoB. Preliminary results verified front-end functionality, and the power consumption of a TIA, STD, quadrature sampler, PWM, and clock multiplier was 26 mW from a 3 V supply. PMID:25571135

  19. Toward a reduced-wire readout system for ultrasound imaging.

    PubMed

    Lim, Jaemyung; Arkan, Evren F; Degertekin, F Levent; Ghovanloo, Maysam

    2014-01-01

    We present a system-on-a-chip (SoC) for use in high-frequency capacitive micromachined ultrasonic transducer (CMUT) imaging systems. This SoC consists of trans-impedance amplifiers (TIA), delay locked loop (DLL) based clock multiplier, quadrature sampler, and pulse width modulator (PWM). The SoC down converts RF echo signal to baseband by quadrature sampling which facilitates modulation. To send data through a 1.6 m wire in the catheter which has limited bandwidth and is vulnerable to noise, the SoC creates a pseudo-digital PWM signal which can be used for back telemetry or wireless readout of the RF data. In this implementation, using a 0.35-μm std. CMOS process, the TIA and single-to-differential (STD) converter had 45 MHz bandwidth, the quadrature sampler had 10.1 dB conversion gain, and the PWM had 5-bit ENoB. Preliminary results verified front-end functionality, and the power consumption of a TIA, STD, quadrature sampler, PWM, and clock multiplier was 26 mW from a 3 V supply. PMID:25571135

  20. A One Chip Hardened Solution for High Speed SpaceWire System Implementations. Session: Components

    NASA Technical Reports Server (NTRS)

    Marshall, Joseph R.; Berger, Richard W.; Rakow, Glenn P.

    2007-01-01

    An Application Specific Integrated Circuit (ASIC) that implements the SpaceWire protocol has been developed in a radiation hardened 0.25 micron CMOS technology. This effort began in March 2003 as a joint development between the NASA Goddard Space Flight Center (GSFC) and BAE Systems. The BAE Systems SpaceWire ASIC is comprised entirely of reusable core elements, many of which are already flight-proven. It incorporates a router with 4 SpaceWire ports and two local ports, dual PC1 bus interfaces, a microcontroller, 32KB of internal memory, and a memory controller for additional external memory use. The SpaceWire cores are also reused in other ASICs under development. The SpaceWire ASIC is planned for use on the Geostationary Operational Environmental Satellites (GOES)-R, the Lunar Reconnaissance Orbiter (LRO) and other missions. Engineering and flight parts have been delivered to programs and users. This paper reviews the SpaceWire protocol and those elements of it that have been built into the current and next SpaceWire reusable cores and features within the core that go beyond the current standard and can be enabled or disabled by the user. The adaptation of SpaceWire to BAE Systems' On Chip Bus (OCB) for compatibility with the other reusable cores will be reviewed and highlighted. Optional configurations within user systems and test boards will be shown. The physical implementation of the design will be described and test results from the hardware will be discussed. Application of this ASIC and other ASICs containing the SpaceWire cores and embedded microcontroller to Plug and Play and reconfigurable implementations will be described. Finally, the BAE Systems roadmap for SpaceWire developments will be updated, including some products already in design as well as longer term plans.

  1. Plasma chemistry in wire chambers

    SciTech Connect

    Wise, J.

    1990-05-01

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed.

  2. Application of Superconducting Power Cables to DC Electric Railway Systems

    NASA Astrophysics Data System (ADS)

    Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru

    For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.

  3. Low speed phaselock speed control system. [for brushless dc motor

    NASA Technical Reports Server (NTRS)

    Fulcher, R. W.; Sudey, J. (Inventor)

    1975-01-01

    A motor speed control system for an electronically commutated brushless dc motor is provided which includes a phaselock loop with bidirectional torque control for locking the frequency output of a high density encoder, responsive to actual speed conditions, to a reference frequency signal, corresponding to the desired speed. The system includes a phase comparator, which produces an output in accordance with the difference in phase between the reference and encoder frequency signals, and an integrator-digital-to-analog converter unit, which converts the comparator output into an analog error signal voltage. Compensation circuitry, including a biasing means, is provided to convert the analog error signal voltage to a bidirectional error signal voltage which is utilized by an absolute value amplifier, rotational decoder, power amplifier-commutators, and an arrangement of commutation circuitry.

  4. Discharging a DC bus capacitor of an electrical converter system

    DOEpatents

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  5. Manchester Coding Option for SpaceWire: Providing Choices for System Level Design

    NASA Technical Reports Server (NTRS)

    Rakow, Glenn; Kisin, Alex

    2014-01-01

    This paper proposes an optional coding scheme for SpaceWire in lieu of the current Data Strobe scheme for three reasons. First reason is to provide a straightforward method for electrical isolation of the interface; secondly to provide ability to reduce the mass and bend radius of the SpaceWire cable; and thirdly to provide a means for a common physical layer over which multiple spacecraft onboard data link protocols could operate for a wide range of data rates. The intent is to accomplish these goals without significant change to existing SpaceWire design investments. The ability to optionally use Manchester coding in place of the current Data Strobe coding provides the ability to DC balanced the signal transitions unlike the SpaceWire Data Strobe coding; and therefore the ability to isolate the electrical interface without concern. Additionally, because the Manchester code has the clock and data encoded on the same signal, the number of wires of the existing SpaceWire cable could be optionally reduced by 50. This reduction could be an important consideration for many users of SpaceWire as indicated by the already existing effort underway by the SpaceWire working group to reduce the cable mass and bend radius by elimination of shields. However, reducing the signal count by half would provide even greater gains. It is proposed to restrict the data rate for the optional Manchester coding to a fixed data rate of 10 Megabits per second (Mbps) in order to make the necessary changes simple and still able to run in current radiation tolerant Field Programmable Gate Arrays (FPGAs). Even with this constraint, 10 Mbps will meet many applications where SpaceWire is used. These include command and control applications and many instruments applications with have moderate data rate. For most NASA flight implementations, SpaceWire designs are in rad-tolerant FPGAs, and the desire to preserve the heritage design investment is important for cost and risk considerations. The

  6. Test wire for high voltage power supply crowbar system

    SciTech Connect

    Bradley, J.T. III; Collins, M.

    1997-09-01

    The klystron microwave amplifier tubes used in the Low Energy Demonstration Accelerator (LEDA) and to be used in the Accelerator Production of Tritium (APT) plant have a strict upper limit on the amount of energy which can be safely dissipated within the klystron`s vacuum envelope during a high voltage arc. One way to prevent damage from occurring to the klystron microwave amplifier tube is through the use of a crowbar circuit which diverts the energy stored in the power supply filter capacitors from the tube arc. The crowbar circuit must be extremely reliable. To test the crowbar circuit, a wire that is designed to fuse when it absorbs a predetermined amount of energy is switched between the high voltage output terminals. The energy required to fuse the wire was investigated for a variety of circuits that simulated the power supply circuit. Techniques for calculating wire length and energy are presented along with verifying experimental data.

  7. Study of a piezoelectric transformer-based DC/DC converter with a cooling system and current-doubler rectifier

    NASA Astrophysics Data System (ADS)

    Su, Yu-Hao; Liu, Yuan-Ping; Vasic, Dejan; Costa, Francois; Wu, Wen-Jong; Lee, Chuih-Kung

    2013-09-01

    The objective of this study was to increase the output current and power in a piezoelectric transformer (PT)-based DC/DC converter by using a cooling system. It is known that the output current of a PT is limited by temperature build-up because of losses, especially when driving at high vibration velocity. Although connecting different inductive circuits at the PT secondary terminal can increase the output current, the root cause of the temperature build-up problem has not yet been solved. This paper presents a study of a PT with cooling system in a DC/DC converter with a commonly used full-bridge rectifier and current-doubler rectifier. The advantages and disadvantages of the proposed technique were investigated. A theoretical-phenomenological model was developed to explain the relationship between the losses and the temperature rise. It will be shown that the vibration velocity as well as heat generation increases the losses. In our design, the maximum output current capacity can increase by 100% when the temperature of operation of the PT is kept below 55 ° C. The study comprises a theoretical part and experimental proof-of-concept demonstration of the proposed design method.

  8. Use Conditions and Efficiency Measurements of DC Power Optimizers for Photovoltaic Systems: Preprint

    SciTech Connect

    Deline, C.; MacAlpine, S.

    2013-10-01

    No consensus standard exists for estimating annual conversion efficiency of DC-DC converters or power optimizers in photovoltaic (PV) applications. The performance benefits of PV power electronics including per-panel DC-DC converters depend in large part on the operating conditions of the PV system, along with the performance characteristics of the power optimizer itself. This work presents acase study of three system configurations that take advantage of the capabilities of DC power optimizers. Measured conversion efficiencies of DC-DC converters are applied to these scenarios to determine the annual weighted operating efficiency. A simplified general method of reporting weighted efficiency is given, based on the California Energy Commission's CEC efficiency rating and severalinput / output voltage ratios. Efficiency measurements of commercial power optimizer products are presented using the new performance metric, along with a description of the limitations of the approach.

  9. Advanced medium-voltage bidirectional dc-dc conversion systems for future electric energy delivery and management systems

    NASA Astrophysics Data System (ADS)

    Fan, Haifeng

    2011-12-01

    The distributed renewable energy generation and utilization are constantly growing, and are expected to be integrated with the conventional grid. The growing pressure for innovative solutions will demand power electronics to take an even larger role in future electric energy delivery and management systems, since power electronics are required for the conversion and control of electric energy by most dispersed generation systems Furthermore, power electronics systems can provide additional intelligent energy management, grid stability and power quality capabilities. Medium-voltage isolated dc-dc converter will become one of the key interfaces for grid components with moderate power ratings. To address the demand of medium voltage (MV) and high power capability for future electric energy delivery and management systems, the power electronics community and industry have been reacting in two different ways: developing semiconductor technology or directly connecting devices in series/parallel to reach higher nominal voltages and currents while maintaining conventional converter topologies; and by developing new converter topologies with traditional semiconductor technology, known as multilevel converters or modular converters. The modular approach uses the well-known, mature, and cheaper power semiconductor devices by adopting new converter topologies. The main advantages of the modular approach include: significant improvement in reliability by introducing desired level of redundancy; standardization of components leading to reduction in manufacturing cost and time; power systems can be easily reconfigured to support varying input-output specifications; and possibly higher efficiency and power density of the overall system. Input-series output-parallel (ISOP) modular configuration is a good choice to realize MV to low voltage (LV) conversion for utility application. However, challenges still remain. First of all, for the high-frequency MV utility application, the low

  10. Beam Emittance Measurement with Laser Wire Scanners in the ILC Beam Delivery System

    SciTech Connect

    Agapov, I.; Blair, G.A.; Woodley, M.; /SLAC

    2008-02-01

    Accurate measurement of the beam phase-space is essential for the next generation of electron accelerators. A scheme for beam optics optimization and beam matrix reconstruction algorithms for the diagnostics section of the beam delivery system of the International Linear Collider based on laser-wire beam profile monitors are discussed. Possible modes of operation of the laser-wire system together with their corresponding performance are presented. Based on these results, prospects for reconstructing the ILC beam emittance from representative laser-wire beam size measurements are evaluated.

  11. 75 FR 65052 - Consensus Standards, Standard Practice for Maintenance of Airplane Electrical Wiring Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ... TRANSPORTATION Federal Aviation Administration Consensus Standards, Standard Practice for Maintenance of Airplane... Practice for Maintenance of Airplane Electrical Wiring Systems (Standard Practice) as an acceptable means... FAA finds the standards to be acceptable methods and procedures for maintenance of electrical...

  12. 30 CFR 75.705-11 - Use of grounded messenger wires; ungrounded systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.705-11 Use of grounded messenger wires; ungrounded systems. Solely for purposes of grounding... may be used as a grounding medium....

  13. 30 CFR 75.705-11 - Use of grounded messenger wires; ungrounded systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Grounding § 75.705-11 Use of grounded messenger wires; ungrounded systems. Solely for purposes of grounding... may be used as a grounding medium....

  14. Research study on multi-KW-DC distribution system

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.; Krausz, A.

    1975-01-01

    A detailed definition of the HVDC test facility and the equipment required to implement the test program are provided. The basic elements of the test facility are illustrated, and consist of: the power source, conventional and digital supervision and control equipment, power distribution harness and simulated loads. The regulated dc power supplies provide steady-state power up to 36 KW at 120 VDC. Power for simulated line faults will be obtained from two banks of 90 ampere-hour lead-acid batteries. The relative merits of conventional and multiplexed power control will be demonstrated by the Supervision and Monitor Unit (SMU) and the Automatically Controlled Electrical Systems (ACES) hardware. The distribution harness is supported by a metal duct which is bonded to all component structures and functions as the system ground plane. The load banks contain passive resistance and reactance loads, solid state power controllers and active pulse width modulated loads. The HVDC test facility is designed to simulate a power distribution system for large aerospace vehicles.

  15. A Theory of Control for a Class of Electronic Power Processing Systems: Energy-Storage DC-To-DC Converters. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Burns, W. W., III

    1977-01-01

    An analytically derived approach to the control of energy-storage dc-to-dc converters, which enables improved system performance and an extensive understanding of the manner in which this improved performance is accomplished, is presented. The control approach is derived from a state-plane analysis of dc-to-dc converter power stages which enables a graphical visualization of the movement of the system state during both steady state and transient operation. This graphical representation of the behavior of dc-to-dc converter systems yields considerable qualitative insight into the cause and effect relationships which exist between various commonly used converter control functions and the system performance which results from them.

  16. NASA requirements and applications environments for electrical power wiring

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammond, Ahmad N.

    1992-01-01

    While a large data base for electrical arc track-resistant wire insulation exists for aircraft electrical power systems, comparable spacecraft-pertinent data are in limited supply. Existing insulation systems have been found to arc-track at potentials as low as 28 V dc. An account is presently given of the electrical, thermal, mechanical, and operational requirements for specification and testing of candidate wiring systems for spacecraft applications.

  17. The wiring diagram of a glomerular olfactory system.

    PubMed

    Berck, Matthew E; Khandelwal, Avinash; Claus, Lindsey; Hernandez-Nunez, Luis; Si, Guangwei; Tabone, Christopher J; Li, Feng; Truman, James W; Fetter, Rick D; Louis, Matthieu; Samuel, Aravinthan Dt; Cardona, Albert

    2016-01-01

    The sense of smell enables animals to react to long-distance cues according to learned and innate valences. Here, we have mapped with electron microscopy the complete wiring diagram of the Drosophila larval antennal lobe, an olfactory neuropil similar to the vertebrate olfactory bulb. We found a canonical circuit with uniglomerular projection neurons (uPNs) relaying gain-controlled ORN activity to the mushroom body and the lateral horn. A second, parallel circuit with multiglomerular projection neurons (mPNs) and hierarchically connected local neurons (LNs) selectively integrates multiple ORN signals already at the first synapse. LN-LN synaptic connections putatively implement a bistable gain control mechanism that either computes odor saliency through panglomerular inhibition, or allows some glomeruli to respond to faint aversive odors in the presence of strong appetitive odors. This complete wiring diagram will support experimental and theoretical studies towards bridging the gap between circuits and behavior. PMID:27177418

  18. A Three-Channel DC SQUID System Using Time-Domain Multiplexing

    NASA Astrophysics Data System (ADS)

    Korn, Matthias; Mueck, Michael; Mugford, Chas; Kycia, Jan

    2004-03-01

    Conventional multichannel SQUID systems require SQUID readout electronics for each channel, as well as many wires connecting the individual SQUIDs and feedback coils to the room temperature electronics. We have studied a time domain multiplexed readout scheme which requires only a single SQUID readout which is successively switched between all SQUIDs. By connecting all SQUIDs and all feedback coils in series, the system requires only a few wires between SQUIDs and room temperature readout.

  19. Measurements of the dc Josephson current in proximity systems

    SciTech Connect

    Camerlingo, C.; Monaco, R.; Ruggiero, B.; Russo, M. ); Testa, G. )

    1995-03-01

    Junctions modeled as [ital S]-[ital N]/[ital I]/[ital S] and [ital S]-[ital N]/[ital I]/[ital N]-[ital S] proximity systems (where [ital S], [ital I], and [ital N] indicate a superconductor, an insulator, and a normal metal, respectively) are widely discussed in literature from both the experimental and theoretical point of view. In the present paper experimental aspects concerning Nb/Nb junctions including a proximity bilayer are considered. Nb-[ital M]/[ital I]/Nb and [ital M]-Nb/[ital I]/Nb structures (where [ital M] is a normal metal, a semimetal, or a superconductor) are investigated by using a semimetal (bismuth) and a superconductor (aluminum) as the [ital M] layer. In particular, how the deposition of a back layer influences the behavior of Nb/[ital I]/Nb high-quality junctions is discussed, focusing the interest on measurements of the temperature dependence of the maximum dc Josephson current. Experimental data are discussed in the framework of Kresin's theoretical calculations based on the thermodynamic Green's function method.

  20. The DC-SQUID-based Magnetocardiographic Systems for Clinical Use

    NASA Astrophysics Data System (ADS)

    Maslennikov, Yu. V.; Primin, M. A.; Slobodchikov, V. Yu.; Khanin, V. V.; Nedayvoda, I. V.; Krymov, V. A.; Okunev, A. V.; Moiseenko, E. A.; Beljaev, A. V.; Rybkin, V. S.; Tolcheev, A. V.; Gapelyuk, A. V.

    The new line of dc-SQUID-based magnetocardiographic (MCG) systems (named as the "MAG-SCAN"-family) is designed, fabricated and tested. These systems are intended for routine MCG investigations of patients at conditions of real clinical electrophysiological labs. The "MAG-SCAN"-family includes the line of MCG devices compatible in terms of hardware and software with number of measuring channels from 1 to 36. Experimental prototypes of 7- and 9-channel MCG-systems (the models "MAG-SCAN-07" and "MAG-SCAN-09" fabricated at CRYOTON Co. Ltd.) were installed in a few hospitals of Moscow city and operated in an unshielded environment of usual clinical labs. Well balanced second-order gradiometers have been used for MCG data recording. They demonstrated an intrinsic noise level better than 5 fT/√Hz. The total noise level of about 20-40 fT/√Hz was measured at urban conditions of Moscow city. The package of special software (named as the "SOFTMAG") was developed as two autonomous subsystems that allow the preprocessing of the heart magnetic signals and the spatio-temporal analysis of the field characteristics and the field sources. The software employs the algorithms for the analysis and estimation of the spatio-temporal characteristics of the heart magnetic field and the correspondent electrical currents distributions. More than 2000 investigations of different volunteers including healthy persons, patients with high blood-pressure, ischemic disease (IHD), chronic obstructive pulmonary disease (COPD) and bronchial asthma (BA) were carried out and sets of MCG-parameters specific for each group were found.

  1. Novel DC ring topology and protection system - a comprehensive solution for mega city power grids

    NASA Astrophysics Data System (ADS)

    Haj-Maharsi, Mohamed Yassine

    2009-07-01

    The development of mega cities leads to increased load concentration and brings additional challenges to managing the electrical grid while keeping power available for critical loads. Techniques using FACTS devices are being applied to alleviate power management difficulties and to confine faults in their originating areas in order to limit the risk of cascading failures in the grid. The addition of many FACTS devices often results in control and protection coordination difficulties, power oscillations between connected networks, subsynchronous resonance problems, and torsional interactions with nearby generator units. The most effective solution is obtained when the individual AC subsystems representing sources and loads are decoupled so a fault in a given subsystem is not propagated to another subsystem. This solution can be achieved by the deployment of a DC system where power sources and loads are connected to the DC bus through voltage source converters. For a mega city, this would be conceived as a DC ring feeding multiple loads and connected to remote and local power sources. Unfortunately, the lack of fast DC circuit breakers has been one of the key issues affecting extensive applications of DC systems with common DC buses; a DC fault would discharge all the capacitors of the DC bus and cause delays in system recovery and possibly a wide system collapse. In this research, I provide a comprehensive solution to mega city power grid problems by proposing a DC system topology that enables grid expansions without affecting existing protection settings or changing existing AC breaker ratings. I also propose the means for protecting the DC system by designing a fast DC breaker and developing a control algorithm capable of isolating DC faults without blocking converter stations or depleting DC bus capacitors. My contribution is three folds: (1) I modeled and simulated Shanghai power grid and performed a study to identify short circuit and voltage stability problems

  2. Study on nondestructive detection system based on x-ray for wire ropes conveyer belt

    NASA Astrophysics Data System (ADS)

    Miao, Changyun; Shi, Boya; Wan, Peng; Li, Jie

    2008-03-01

    A nondestructive detection system based on X-ray for wire ropes conveyer belt is designed by X-ray detection technology. In this paper X-ray detection principle is analyzed, a design scheme of the system is presented; image processing of conveyer belt is researched and image processing algorithms are given; X-ray acquisition receiving board is designed with the use of FPGA and DSP; the software of the system is programmed by C#.NET on WINXP/WIN2000 platform. The experiment indicates the system can implement remote real-time detection of wire ropes conveyer belt images, find faults and give an alarm in time. The system is direct perceived, strong real-time and high accurate. It can be used for fault detection of wire ropes conveyer belts in mines, ports, terminals and other fields.

  3. The wiring diagram of a glomerular olfactory system

    PubMed Central

    Berck, Matthew E; Khandelwal, Avinash; Claus, Lindsey; Hernandez-Nunez, Luis; Si, Guangwei; Tabone, Christopher J; Li, Feng; Truman, James W; Fetter, Rick D; Louis, Matthieu; Samuel, Aravinthan DT; Cardona, Albert

    2016-01-01

    The sense of smell enables animals to react to long-distance cues according to learned and innate valences. Here, we have mapped with electron microscopy the complete wiring diagram of the Drosophila larval antennal lobe, an olfactory neuropil similar to the vertebrate olfactory bulb. We found a canonical circuit with uniglomerular projection neurons (uPNs) relaying gain-controlled ORN activity to the mushroom body and the lateral horn. A second, parallel circuit with multiglomerular projection neurons (mPNs) and hierarchically connected local neurons (LNs) selectively integrates multiple ORN signals already at the first synapse. LN-LN synaptic connections putatively implement a bistable gain control mechanism that either computes odor saliency through panglomerular inhibition, or allows some glomeruli to respond to faint aversive odors in the presence of strong appetitive odors. This complete wiring diagram will support experimental and theoretical studies towards bridging the gap between circuits and behavior. DOI: http://dx.doi.org/10.7554/eLife.14859.001 PMID:27177418

  4. 30 CFR 77.902-2 - Approved ground check systems not employing pilot check wires.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved ground check systems not employing... Approved ground check systems not employing pilot check wires. Ground check systems not employing pilot... includes a fail safe design causing the circuit breaker to open when ground continuity is broken....

  5. Bond strengths of three resin systems used with brackets and embedded wire attachments.

    PubMed

    Schulz, R P; Mayhew, R B; Oesterle, L J; Pierson, W P

    1985-01-01

    Orthodontic wire bonded directly to teeth with a resin adhesive system has been used to establish anchor units for procedures in orthodontics as well as for splinting teeth in other disciplines. This procedure can save the cost and time of placing a bracket. In addition, several different resin systems have been used for this procedure as well as for placing brackets. The purpose of this study was to determine the strength of three adhesive systems used to bond orthodontic wires directly to teeth and to compare these values with those found for directly bonded orthodontic brackets. Equal sample sizes of brackets or wires were attached to 240 human teeth with either Concise, Miradept, or Endur in a standardized area of etched enamel. Shear and tensile strengths were measured at 30 minutes and at 48 hours. At 30 minutes brackets were significantly stronger than embedded wires, and Concise was significantly stronger than either of the other resins. However, all significant differences between any of the three resin systems using either bonded brackets or wires disappeared at 48 hours. Whether or not this initial strength difference is clinically significant remains speculative. PMID:3155593

  6. Adaptable DC offset correction

    NASA Technical Reports Server (NTRS)

    Golusky, John M. (Inventor); Muldoon, Kelly P. (Inventor)

    2009-01-01

    Methods and systems for adaptable DC offset correction are provided. An exemplary adaptable DC offset correction system evaluates an incoming baseband signal to determine an appropriate DC offset removal scheme; removes a DC offset from the incoming baseband signal based on the appropriate DC offset scheme in response to the evaluated incoming baseband signal; and outputs a reduced DC baseband signal in response to the DC offset removed from the incoming baseband signal.

  7. Turbulence Measurements by the DC-8 Meteorological Measurement System

    NASA Technical Reports Server (NTRS)

    Chan, K. R.; Dean-Day, J.; Bowen, S. W.; Bui, T. P.; Chan, K. Roland (Technical Monitor)

    1997-01-01

    The instrumentation of a new MMS on the DC-8 aircraft is briefly described. Methods to compute and evaluate the turbulent dissipation rate epsilon, based on theory and MMS data, are discussed. Examples of turbulence measurements during encounters of a wake vortex, wave clouds, persistent contrails, mountain are gravity waves are illustrated.

  8. DC drive system for cine/pulse cameras

    NASA Technical Reports Server (NTRS)

    Gerlach, R. H.; Sharpsteen, J. T.; Solheim, C. D.; Stoap, L. J.

    1977-01-01

    Camera-drive functions are separated mechanically into two groups which are driven by two separate dc brushless motors. First motor, a 90 deg stepper, drives rotating shutter; second electronically commutated motor drives claw and film transport. Shutter is made of one piece but has two openings for slow and fast exposures.

  9. An Optimal Control Strategy for DC Bus Voltage Regulation in Photovoltaic System with Battery Energy Storage

    PubMed Central

    Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M. A.

    2014-01-01

    This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods. PMID:24883374

  10. An optimal control strategy for DC bus voltage regulation in photovoltaic system with battery energy storage.

    PubMed

    Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M A

    2014-01-01

    This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods. PMID:24883374

  11. Innate immune system favors emergency monopoiesis at the expense of DC-differentiation to control systemic bacterial infection in mice.

    PubMed

    Pasquevich, Karina A; Bieber, Kristin; Günter, Manina; Grauer, Matthias; Pötz, Oliver; Schleicher, Ulrike; Biedermann, Tilo; Beer-Hammer, Sandra; Bühring, Hans-Jörg; Rammensee, Hans-Georg; Zender, Lars; Autenrieth, Ingo B; Lengerke, Claudia; Autenrieth, Stella E

    2015-10-01

    DCs are professional APCs playing a crucial role in the initiation of T-cell responses to combat infection. However, systemic bacterial infection with various pathogens leads to DC-depletion in humans and mice. The mechanisms of pathogen-induced DC-depletion remain poorly understood. Previously, we showed that mice infected with Yersinia enterocolitica (Ye) had impaired de novo DC-development, one reason for DC-depletion. Here, we extend these studies to gain insight into the molecular mechanisms of DC-depletion and the impact of different bacteria on DC-development. We show that the number of bone marrow (BM) hematopoietic progenitors committed to the DC lineage is reduced following systemic infection with different Gram-positive and Gram-negative bacteria. This is associated with a TLR4- and IFN-γ-signaling dependent increase of committed monocyte progenitors in the BM and mature monocytes in the spleen upon Ye-infection. Adoptive transfer experiments revealed that infection-induced monopoiesis occurs at the expense of DC-development. Our data provide evidence for a general response of hematopoietic progenitors upon systemic bacterial infections to enhance monocyte production, thereby increasing the availability of innate immune cells for pathogen control, whereas impaired DC-development leads to DC-depletion, possibly driving transient immunosuppression in bacterial sepsis. PMID:26138432

  12. Characteristics of a large system of pad readout wire proportional chambers for the HPC calorimeter

    SciTech Connect

    Camporesi, T.; Cavallo, F.R.; Giordano, V.; Laurenti, G.; Molinari, G.; Navarria, F.L.; Privitera, P.; Rovelli, T.; Valenti, G.; Zucchini, A.

    1989-02-01

    A large system of wire proportional chambers is being constructed for the readout of the High-Density Projection Chamber (HPC) of the DELPHI experiment at the Large Electron-Positron storage ring. The system consists of 144 chambers, each 0.3 m/sup 2/ wide and read out via cathode pads, located at the end of the HPC drift volume.

  13. Three-dimensional wire-mesh capacitor system measures fluid density

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Gaging system automatically measures the bulk density of a stored, electrically nonconductive fluid containing varying portions of liquid and vapor. The system employs a three-dimensional wire-mesh capacitor whose capacitance varies with the bulk density of the fluid dielectric medium between the capacitor plates.

  14. High dynamic range diamond detector acquisition system for beam wire scanner applications

    NASA Astrophysics Data System (ADS)

    Sirvent, J. L.; Dehning, B.; Piselli, E.; Emery, J.; Dieguez, A.

    2016-03-01

    The CERN Beam Instrumentation group has been working during the last years on the beam wire scanners upgrade to cope up with the increasing requirements of CERN experiments. These devices are used to measure the beam profile by crossing a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected and correlated with the wire position to reconstruct the beam profile. The upgraded secondary particles acquisition electronics will use polycrystalline chemical vapour deposition (pCVD) diamond detectors for particle shower measurements, with low noise acquisitions performed on the tunnel, near the detector. The digital data is transmitted to the surface through an optical link with the GBT protocol. Two integrator ASICs (ICECAL and QIE10) are being characterized and compared for detector readout with the complete acquisition chain prototype. This contribution presents the project status, the QIE10 front-end performance and the first measurements with the complete acquisition system prototype. In addition, diamond detector signals from particle showers generated by an operational beam wire scanner are analysed and compared with an operational system.

  15. A Sensorless Speed Control System for DC Motor Drives

    NASA Astrophysics Data System (ADS)

    Georgiev, Tsolo; Mikhov, Mikho

    2009-01-01

    An approach to sensorless speed control of permanent magnet DC motor drives is presented in this paper. The motor speed has been estimated indirectly by the respective back EMF voltage. Using a discrete vector-matrix description of the controlled object, an optimal modal state observer has been synthesized, as well as an optimal modal controller. The results obtained show that the applied control method can ensure good performance.

  16. Combined Operation of AC and DC Distribution System with Distributed Generation Units

    NASA Astrophysics Data System (ADS)

    Noroozian, Reza; Abedi, Mehrdad; Gharehpetian, Gevorg

    2010-07-01

    This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.

  17. Design and Analysis of the Main AC/DC Converter System for ITER

    NASA Astrophysics Data System (ADS)

    Sheng, Zhicai; Xu, Liuwei; Fu, Peng

    2012-04-01

    A design of the main AC/DC converter system for ITER is described and the configuration of the main AC/DC converters is presented. To reduce the reactive power absorbed from the converter units, the main AC/DC converters are designed to be series-connected and work in a sequential mode. The structure of the regulator of the converter system is described. A simulation model was built up for the PSCAD/EMTDC code, and the design was validated accordingly. Harmonic analysis and reactive power calculation of the converters units are presented. The results reveal the advantage of sequential control in reducing reactive power and harmonics.

  18. A simple three-channel dc SQUID system using time domain multiplexing

    NASA Astrophysics Data System (ADS)

    Mück, M.; Korn, M.; Mugford, C. G. A.; Kycia, J. B.

    2004-08-01

    Conventional multichannel superconducting quantum interference device (SQUID) systems require a SQUID read-out circuit for each channel, as well as many wires connecting each individual SQUID and feedback coil to the room temperature electronics. We present a simple time domain multiplexed read-out scheme which requires only a single SQUID read-out circuit that is successively switched between all the SQUIDs. By connecting all the SQUIDs and all the feedback coils in series, this time domain multiplexed system requires many fewer wires between the SQUIDs and the room temperature read-out circuit than other multichannel systems.

  19. Very low noise AC/DC power supply systems for large detector arrays

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Baù, A.; Carniti, P.; Cassina, L.; Giachero, A.; Gotti, C.; Maino, M.; Passerini, A.; Pessina, G.

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μVRMS (CUORE setup) and 90 μVRMS (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled).

  20. Very low noise AC/DC power supply systems for large detector arrays.

    PubMed

    Arnaboldi, C; Baù, A; Carniti, P; Cassina, L; Giachero, A; Gotti, C; Maino, M; Passerini, A; Pessina, G

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μV(RMS) (CUORE setup) and 90 μV(RMS) (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled). PMID:26724052

  1. Development of a uninterrupted power system: ac and dc to dc converter

    NASA Technical Reports Server (NTRS)

    Cronin, D. L.; Schoenfeld, A. D.

    1973-01-01

    This program covered the design, fabrication and testing of an advanced development model uninterrupted power system. The input and output requirements imposed on the power processor were specified such that the unit is electrically interchangeable with existing power systems used by the Federal Aviation Administration in installations which have a history of failure due to electrical transient conditions. Input power is from either of two single-phase ac power sources or batteries with electronic selection and transfer between power sources. Battery reconditioning is automatic when either ac source is present. The output power is rated at 84OW; the nominal output is 24V at 35A. Within the 84OW limit, the regulated output voltage is adjustable from 22V to 30Vdc. Protection against continuous overloading or short circuit is provided. The unit is packaged in a standard 19-inch rack mount configuration with 7-inch panel height. Controls are on the front panel with power input and output through connectors on the rear surface. Cooling is by free convection from fin areas located on the side and rear panels. The packaged unit weighs 52.8 lbs., which can be reduced significantly if a three-phase ac power source is used.

  2. Modular DC-DC converter system for energy harvesting with EAPs

    NASA Astrophysics Data System (ADS)

    Eitzen, L.; Graf, C.; Maas, J.

    2013-04-01

    Energy harvesting with EAPs requires an energy-efficient power electronics providing a bidirectional energy transfer and operating voltages of up to several kilovolts. A possibility to achieve a high energy-efficiency for high voltage conversion is the use of a modular converter system consisting of several bidirectional converter modules, which are connected in series on the converter output side and in parallel at the input side. Since each converter stage provides only a part of the overall converter output voltage, the converter module output voltages can effectively be reduced by choosing the number of cascaded converter modules appropriately. This allows the use of standard semiconductor switches with superior electrical characteristics compared to high voltage semiconductors, enabling a high energy-efficiency and smaller passive components. Since EAP devices exhibit a mainly capacitive behavior and a limitation of the operating current is required for electrode protection, the utilized converter structure/topology has to be operated as a controllable current source on the lowest control level, which is achieved by operating the converter modules of the modular converter system with a subordinate closed-looped current control scheme. In order to avoid voltage unbalances among the single converter modules, a method for voltage balancing is presented. For validation, experimental results of a realized bidirectional flyback converter prototype are presented and discussed.

  3. Secondary particle acquisition system for the CERN beam wire scanners upgrade

    NASA Astrophysics Data System (ADS)

    Sirvent, J. L.; Dehning, B.; Emery, J.; Diéguez, A.

    2015-04-01

    The increasing requirements of CERN experiments make essential the upgrade of beam instrumentation in general, and high accuracy beam profile monitors in particular. The CERN Beam Instrumentation Group has been working during the last years on the Wire Scanners upgrade. These systems cross a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected to reconstruct the beam profile. For the new secondary shower acquisition system, it is necessary to perform very low noise measurements with high dynamic range coverage. The aim is to design a system without tuneable parameters and compatible for any beam wire scanner location at the CERN complex. Polycrystalline chemical vapour deposition diamond detectors (pCVD) are proposed as new detectors for this application because of their radiation hardness, fast response and linearity over a high dynamic range. For the detector readout, the acquisition electronics must be designed to exploit the detector capabilities and perform bunch by bunch measurements at 40MHz. This paper describes the design challenges of such a system, analysing different acquisition possibilities from the signal integrity point of view. The proposed system architecture is shown in detail and the development status presented.

  4. Severe Coronary Spasm in Systemic Lupus Erythematosus Resulting in Recurrent Occlusions and Guide Wire Fracture.

    PubMed

    Lai, Chih-Hung; Lu, Tse-Min; Juan, Yu-Hsiang; Chang, Szu-Ling; Lee, Wen-Lieng; Sung, Shih-Hsien

    2016-07-01

    Middle-aged female patients with systemic lupus erythematosus (SLE) have an increased risk of coronary artery disease and myocardial infarction (MI). We report a case of left anterior descending coronary artery (LAD) MI associated with severe coronary spasm in both the LAD and left circumflex artery, complicated with fracture of the distal wire within the microcatheter which was successfully removed by manual aspiration using an inflation device. From this series of rare complications of SLE with MI, severe coronary spasm and guide wire fracture, we underscore that clinicians performing coronary intervention should be aware of an elevated chance of possible severe coronary spasms in SLE patients. PMID:27471364

  5. Severe Coronary Spasm in Systemic Lupus Erythematosus Resulting in Recurrent Occlusions and Guide Wire Fracture

    PubMed Central

    Lai, Chih-Hung; Lu, Tse-Min; Juan, Yu-Hsiang; Chang, Szu-Ling; Lee, Wen-Lieng; Sung, Shih-Hsien

    2016-01-01

    Middle-aged female patients with systemic lupus erythematosus (SLE) have an increased risk of coronary artery disease and myocardial infarction (MI). We report a case of left anterior descending coronary artery (LAD) MI associated with severe coronary spasm in both the LAD and left circumflex artery, complicated with fracture of the distal wire within the microcatheter which was successfully removed by manual aspiration using an inflation device. From this series of rare complications of SLE with MI, severe coronary spasm and guide wire fracture, we underscore that clinicians performing coronary intervention should be aware of an elevated chance of possible severe coronary spasms in SLE patients. PMID:27471364

  6. 47 CFR 68.213 - Installation of other than “fully protected” non-system simple customer premises wiring.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... non-system simple customer premises wiring. 68.213 Section 68.213 Telecommunication FEDERAL... protected” non-system simple customer premises wiring. (a) Scope of this rule. Provisions of this rule apply... to agreement between it and the customer or undertakings by it, otherwise consistent with...

  7. Differences in the force system delivered by different beta-titanium wires in elaborate designs

    PubMed Central

    Martins, Renato Parsekian; Caldas, Sergei Godeiro Fernandes Rabelo; Ribeiro, Alexandre Antonio; Vaz, Luís Geraldo; Shimizu, Roberto Hideo; Martins, Lídia Parsekian

    2015-01-01

    Abstract Objective: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design. Methods: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.025-in b-Ti were randomly divided into four groups according to wire brand: TMATM(G1), BETA FLEXYTM (G2), BETA III WIRETM (G3) and BETA CNATM (G4). Forces and moments were recorded by a moment transducer, coupled to a digital extensometer indicator adapted to a testing machine, every 0.5 mm of deactivation from 5 mm of the initial activation. The moment-to-force (MF) ratio, the overlapping of the vertical extensions of the TLSs and the load-deflection (LD) ratio were also calculated. To complement the results, the Young's module (YM) of each wire was determined by the slope of the load-deflection graph of a tensile test. The surface chemical composition was also evaluated by an energy dispersive X-ray fluorescence spectrometer. Results: All groups, except for G2, produced similar force levels initially. G3 produced the highest LD rates and G1 and G4 had similar amounts of overlap of the vertical extensions of the TLSs in "neutral position". G1 and G3 delivered the highest levels of moments, and G2 and G3 produced the highest MF ratios. b-Ti wires from G3 produced the highest YM and all groups showed similar composition, except for G2. Conclusion: The four beta-titanium wires analyzed produced different force systems when used in a more elaborate design due to the fact that each wire responds differently to bends. PMID:26691975

  8. Testing of a flat conductor cable baseboard system for residential and commercial wiring

    NASA Technical Reports Server (NTRS)

    Hankins, J. D.

    1974-01-01

    The results of extensive testing (mechanical, electrical, chemical, environmental, thermal, and analytical) are reported for a flat conductor cable baseboard system for residential and commercial wiring. In all of the tests, Underwriters Laboratories (UL) Standards, UL Tentative Test Programs, or Accepted Engineering Practices were followed during test selection, test setup, and test accomplishment.

  9. 14 CFR 26.11 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Electrical wiring interconnection systems... by the FAA Oversight Office. For purposes of this section, the “representative airplane” is the... by the FAA Oversight Office. (2) Ensure that any revised EWIS ICA remain compatible with any...

  10. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Electrical wiring interconnection systems (EWIS) maintenance program. 129.111 Section 129.111 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATIONS:...

  11. Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Levashov, Michael Y.

    2010-12-01

    Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of a quadrupole. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing it. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). The following break up of error was suggested for the fiducialization steps: 10{micro}m for step 1 (finding the center), 20{micro}m for step 2 (finding the wire), and 10{micro}m for step 3 (tooling ball measurements). The purpose of this study is to investigate whether the vibrating wire system meets the requirements for LCLS. In particular, if it can reliably fiducialize a quadrupole magnetic center to within 25{micro}m in both vertical and horizontal directions. The behavior of individual system components is compared to the expected performance

  12. Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Not Available

    2010-11-29

    Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of a quadrupole. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing it. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). The following break up of error was suggested for the fiducialization steps: 10{micro}m for step 1 (finding the center), 20{micro}m for step 2 (finding the wire), and 10{micro}m for step 3 (tooling ball measurements). The purpose of this study is to investigate whether the vibrating wire system meets the requirements for LCLS. In particular, if it can reliably fiducialize a quadrupole magnetic center to within 25{micro}m in both vertical and horizontal directions. The behavior of individual system components is compared to the expected performance

  13. Evolution of the Design of a Second Generation FireWire Based Data Acquisition System

    PubMed Central

    Lewellen, T.K.; Miyaoka, R.S.; MacDonald, L.R.; Haselman, M.; DeWitt, D.; Hauck, S.

    2011-01-01

    Our laboratory has previously reported on the basic design concepts of an updated FireWire based data acquisition system for depth-of-interaction detector systems designed at the University of Washington. The new version of our data acquisition system leverages the capabilities of modern field programmable gate arrays (FPGA) and puts almost all functions into the FPGA, including the FireWire elements, the embedded processor, and pulse timing and integration. The design is centered around an acquisition node board (ANB) that includes 64 serial ADC channels, one high speed parallel ADC, FireWire 1394b support, the FPGA, a serial command bus and signal lines to support a rough coincidence window implementation to reject singles events from being sent on the FireWire bus. Adapter boards convert detector signals into differential paired signals to connect to the ANB. In this paper we discuss many of the design details, including steps taken to minimize the number of layers in the printed circuit board and to avoid skewing of parallel signals and unwanted bandwidth limitations. PMID:22228135

  14. Operation and force analysis of the guide wire in a minimally invasive vascular interventional surgery robot system

    NASA Astrophysics Data System (ADS)

    Yang, Xue; Wang, Hongbo; Sun, Li; Yu, Hongnian

    2015-03-01

    To develop a robot system for minimally invasive surgery is significant, however the existing minimally invasive surgery robots are not applicable in practical operations, due to their limited functioning and weaker perception. A novel wire feeder is proposed for minimally invasive vascular interventional surgery. It is used for assisting surgeons in delivering a guide wire, balloon and stenting into a specific lesion location. By contrasting those existing wire feeders, the motion methods for delivering and rotating the guide wire in blood vessel are described, and their mechanical realization is presented. A new resistant force detecting method is given in details. The change of the resistance force can help the operator feel the block or embolism existing in front of the guide wire. The driving torque for rotating the guide wire is developed at different positions. Using the CT reconstruction image and extracted vessel paths, the path equation of the blood vessel is obtained. Combining the shapes of the guide wire outside the blood vessel, the whole bending equation of the guide wire is obtained. That is a risk criterion in the delivering process. This process can make operations safer and man-machine interaction more reliable. A novel surgery robot for feeding guide wire is designed, and a risk criterion for the system is given.

  15. Optimized efficiency of all-electric ships by dc hybrid power systems

    NASA Astrophysics Data System (ADS)

    Zahedi, Bijan; Norum, Lars E.; Ludvigsen, Kristine B.

    2014-06-01

    Hybrid power systems with dc distribution are being considered for commercial marine vessels to comply with new stringent environmental regulations, and to achieve higher fuel economy. In this paper, detailed efficiency analysis of a shipboard dc hybrid power system is carried out. An optimization algorithm is proposed to minimize fuel consumption under various loading conditions. The studied system includes diesel engines, synchronous generator-rectifier units, a full-bridge bidirectional converter, and a Li-Ion battery bank as energy storage. In order to evaluate potential fuel saving provided by such a system, an online optimization strategy for fuel consumption is implemented. An Offshore Support Vessel (OSV) is simulated over different operating modes using the online control strategy. The resulted consumed fuel in the simulation is compared to that of a conventional ac power system, and also a dc power system without energy storage. The results show that while the dc system without energy storage provides noticeable fuel saving compared to the conventional ac system, optimal utilization of the energy storage in the dc system results in twice as much fuel saving.

  16. System and Method for Determining Rate of Rotation Using Brushless DC Motor

    NASA Technical Reports Server (NTRS)

    Howard, David E. (Inventor); Smith, Dennis A. (Inventor)

    2000-01-01

    A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is squared. The squared outputs associated with each winding are combined, with the square root being taken of such combination, to produce a DC output proportional only to the rate of rotation of the motor's shaft.

  17. The electron dose monitoring and control system in EB radiation processing for wires and cables

    NASA Astrophysics Data System (ADS)

    Zhou, Xinzhi; Zhou, Yong; Zhou, Youyi; Tang, Qiang

    2002-03-01

    This paper introduces a close-loop microcomputer control system used for EB radiation processing of wires and cables, which is based on the measurements and calculations of the absorbed dose distribution of 0.6-2.0 MeV electrons in circular compound materials. The calculation of electron energy deposition in 4-layer media is carried out by the bipartition model of electron transport. The design ideas, system configuration and implementation of this control system governed by a 586 personal computer under windows 98 OS are described in this paper. The field operation results such as control precision and step response curves of this system are also given. The control system has been used for EB radiation processing of wires.

  18. Department of Energy`s Wire Development Workshop - Superconductivity program for electric systems

    SciTech Connect

    1996-06-01

    The 1996 High-Temperature Superconducting Wire Development Workshop was held on January 31--February 1 at the Crown Plaza Tampa Westshore in Tampa, Florida. The meeting was hosted by Tampa Electric Company and sponsored by the Department of Energy`s Superconductivity Program for Electric Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. Tampa Electric`s Greg Ramon began the meeting by giving a perspective on the changes now occurring in the utility sector. Major program wire development accomplishments during the past year were then highlighted, particularly the world record achievements at Los Alamos and Oak Ridge National Laboratories. The meeting then focussed on three priority technical issues: thallium conductors; AC losses in HTS conductors; and coated conductors on textured substrates. Following in-depth presentations, working groups were formed in each technology area to discuss and critique the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  19. 77 FR 58424 - Drucker, Inc., DynaMotive Energy Systems Corp., and Gate to Wire Solutions, Inc., Order of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Drucker, Inc., DynaMotive Energy Systems Corp., and Gate to Wire Solutions, Inc., Order of... current and accurate information concerning the securities of Gate to Wire Solutions, Inc. because it...

  20. International space station wire program

    NASA Technical Reports Server (NTRS)

    May, Todd

    1995-01-01

    Hardware provider wire systems and current wire insulation issues for the International Space Station (ISS) program are discussed in this viewgraph presentation. Wire insulation issues include silicone wire contamination, Tefzel cold temperature flexibility, and Russian polyimide wire insulation. ISS is a complex program with hardware developed and managed by many countries and hundreds of contractors. Most of the obvious wire insulation issues are known by contractors and have been precluded by proper selection.

  1. Static state estimation of multiterminal DC/AC power system in rectangular co-ordinates

    SciTech Connect

    Roy, L.; Sinha, A.K. ); Srivastava, H.N.P. )

    1991-01-01

    This paper describes a simple, efficient and reliable method for estimating the state of an integrated multiterminal HVDC/AC power system in the rectangular coordinate form. A six variable model is used to represent the converter system. The proposed algorithm performs successfully in obtaining the state of an AC system with a DC link or a multiterminal DC network. It is possible to implement it for an on-line state estimation. Simulation results of a 30-busbar system are presented for illustration.

  2. Cryogenic Cooling System for 5 kA, 200 μH Class HTS DC Reactor

    NASA Astrophysics Data System (ADS)

    Park, Heecheol; Kim, Seokho; Kim, Kwangmin; Park, Minwon; Park, Taejun; Kim, A.-rong; Lee, Sangjin

    DC reactors, made by aluminum busbar, are used to stabilize the arc of an electric furnace. In the conventional arc furnace, the transport current is several tens of kilo-amperes and enormous resistive loss is generated. To reduce the resistive loss at the DC reactor, a HTS DC reactor can be considered. It can dramatically improve the electric efficiency as well as reduce the installation space. Similar with other superconducting devices, the HTS DC reactor requires current leads from a power source in room temperature to the HTS coil in cryogenic environment. The heat loss at the metal current leads can be minimized through optimization process considering the geometry and the transport current. However, the transport current of the HTS DC reactor for the arc furnace is much larger than most of HTS magnets and the enormous heat penetration through the current lead should be effectively removed to keep the temperature around 70∼77 K. Current leads are cooled down by circulation of liquid nitrogen from the cooling system with a stirling cryocooler. The operating temperature of HTS coil is 30∼40 K and circulation of gaseous helium is used to remove the heat generation at the HTS coil. Gaseous helium is transported through the cryogenic helium blower and a single stage GM cryocooler. This paper describes design and experimental results on the cooling system for current leads and the HTS coil of 5 kA, 200 μH class DC reactor as a prototype. The results are used to verify the design values of the cooling systems and it will be applied to the design of scale-up cooling system for 50 kA, 200 μH class DC reactor.

  3. Reliability of hybrid photovoltaic DC micro-grid systems for emergency shelters and other applications

    NASA Astrophysics Data System (ADS)

    Dhere, Neelkanth G.; Schleith, Susan

    2014-10-01

    Improvement of energy efficiency in the SunSmart Schools Emergency Shelters requires new methods for optimizing the energy consumption within the shelters. One major limitation in current systems is the requirement of converting direct current (DC) power generated from the PV array into alternating current (AC) power which is distributed throughout the shelters. Oftentimes, this AC power is then converted back to DC to run certain appliances throughout the shelters resulting in a significant waste of energy due to DC to AC and then again AC to DC conversion. This paper seeks to extract the maximum value out of PV systems by directly powering essential load components within the shelters that already run on DC power without the use of an inverter and above all to make the system reliable and durable. Furthermore, additional DC applications such as LED lighting, televisions, computers and fans operated with DC brushless motors will be installed as replacements to traditional devices in order to improve efficiency and reduce energy consumption. Cost of energy storage technologies continue to decline as new technologies scale up and new incentives are put in place. This will provide a cost effective way to stabilize the energy generation of a PV system as well as to provide continuous energy during night hours. It is planned to develop a pilot program of an integrated system that can provide uninterrupted DC power to essential base load appliances (heating, cooling, lighting, etc.) at the Florida Solar Energy Center (FSEC) command center for disaster management. PV arrays are proposed to be installed on energy efficient test houses at FSEC as well as at private homes having PV arrays where the owners volunteer to participate in the program. It is also planned to monitor the performance of the PV arrays and functioning of the appliances with the aim to improve their reliability and durability. After a successful demonstration of the hybrid DC microgrid based emergency

  4. A novel method for simulation of brushless DC motor servo-control system based on MATLAB

    NASA Astrophysics Data System (ADS)

    Tao, Keyan; Yan, Yingmin

    2006-11-01

    This paper provides a research about the simulation of brush-less DC motor (BLDCM) servo control system. Based on the mathematical model of Brush-less DC motor (BLDCM), built the system simulation model with the MATLAB software. When the system model is made, the isolated functional blocks, such as BLDCM block, the rotor's position detection block, change-phase logic block etc. have been modeled. By the organic combination of these blocks, the model of BLDCM can be established easily. The reasonability and validity have been testified by the simulation results and this novel method offers a new thought way for designing and debugging actual motors.

  5. System Security Authorization Agreement (SSAA) for the WIRE Archive and Research Facility

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Wide-Field Infrared Explorer (WIRE) Archive and Research Facility (WARF) is operated and maintained by the Department of Physics, USAF Academy. The lab is located in Fairchild Hall, 2354 Fairchild Dr., Suite 2A103, USAF Academy, CO 80840. The WARF will be used for research and education in support of the NASA Wide Field Infrared Explorer (WIRE) satellite, and for related high-precision photometry missions and activities. The WARF will also contain the WIRE preliminary and final archives prior to their delivery to the National Space Science Data Center (NSSDC). The WARF consists of a suite of equipment purchased under several NASA grants in support of WIRE research. The core system consists of a Red Hat Linux workstation with twin 933 MHz PIII processors, 1 GB of RAM, 133 GB of hard disk space, and DAT and DLT tape drives. The WARF is also supported by several additional networked Linux workstations. Only one of these (an older 450 Mhz PIII computer running Red Hat Linux) is currently running, but the addition of several more is expected over the next year. In addition, a printer will soon be added. The WARF will serve as the primary research facility for the analysis and archiving of data from the WIRE satellite, together with limited quantities of other high-precision astronomical photometry data from both ground- and space-based facilities. However, the archive to be created here will not be the final archive; rather, the archive will be duplicated at the NSSDC and public access to the data will generally take place through that site.

  6. Preparation of Dy-123 system superconductor composed with Pt Rh wires

    NASA Astrophysics Data System (ADS)

    Shimada, H.; Fujimoto, H.; Yoshizawa, S.

    2008-09-01

    The melt-textured DyBa 2Cu 3O x (Dy-123) system superconductors were grown by means of the top seeding and temperature gradient method. Ag 2O powder of 30 wt% was added to the mixture of Dy-123 and Dy-211 powder. The pellet of 20 mm in diameter and 20 mm in thickness was prepared using coaxial pressing equipment. For improving the mechanical property and resolving the hot-spot problem, platinum-rhodium (Pt-Rh) alloy wires 0.4 mm in diameter and 18 mm in length were added from the surface into the bottom of the pellet. The pellet was partially melted in air at 1030 °C for one hr and rapidly cooled to 975 °C in a bulk material, where Nd-123 seed crystal was placed in contact with the top surface of the bulk. After the seeding, the bulk was cooled to 925 °C, and then furnace-cooled to the room temperature. Finally, the sample was annealed in oxygen atmosphere. The single-domain superconducting bulk containing two Pt-Rh wires was fabricated. There were intermediate layers and no voids or cracks between the metal wire and Dy-123 superconducting oxide. Single peak in the trapped field distribution with the maximum value of about 0.12 T at 77.3 K was obtained, which was almost the same as that of the bulk without wires. It was concluded that the superconductivity of the melt textured bulk was not deteriorated by the addition of Pt-Rh wires.

  7. Cable Bundle Wire Derating

    NASA Technical Reports Server (NTRS)

    Lundquist, Ray A.; Leidecker, Henning

    1998-01-01

    The allowable operating currents of electrical wiring when used in the space vacuum environment is predominantly determined by the maximum operating temperature of the wire insulation. For Kapton insulated wire this value is 200 C. Guidelines provided in the Goddard Space Flight Center (GSFC) Preferred Parts List (PPL) limit the operating current of wire within vacuum to ensure the maximum insulation temperature is not exceeded. For 20 AWG wire, these operating parameters are: (1) 3.7 amps per wire; (2) bundle of 15 or more wires; (3) 70 C environment: and (4) vacuum of 10(exp -5) torr or less. To determine the behavior and temperature of electrical wire at different operating conditions, a thermal vacuum test was performed on a representative electrical harness of the Hubble Space Telescope (HST) power distribution system. This paper describes the test and the results.

  8. Cable Bundle Wire Derating

    NASA Technical Reports Server (NTRS)

    Lundquist, Ray A.; Leidecker, Henning

    1999-01-01

    The allowable operating currents of electrical wiring when used in the space vacuum environment is predominantly determined by the maximum operating temperature of the wire insulation. For Kapton insulated wire this value is 200 degree C. Guidelines provided in the Goddard Space Flight Center (GSFC) Preferred Parts List (PPL) limit the operating current of wire within vacuum to ensure the maximum insulation temperature is not exceeded. For 20 AWG wire, these operating parameters are: (1) 3.7 amps per wire (2) bundle of 15 or more wires (3) 70 C environment (4) vacuum of 10(exp -5) torr or less To determine the behavior and temperature of electrical wire at different operating conditions, a thermal vacuum test was performed on a representative electrical harness of the Hubble Space Telescope (HST) power distribution system. This paper describes the test and the results.

  9. Cable Bundle Wire Derating

    NASA Technical Reports Server (NTRS)

    Lundquist, Ray A.; Leidecker, Henning

    1998-01-01

    The allowable operating currents of electrical wiring when used in the space vacuum environment is predominantly determined by the maximum operating temperature of the wire insulation. For Kapton insulated wire this value is 200 C. Guidelines provided in the Goddard Space Flight Center (GSFC) Preferred Parts List (PPL) limit the operating current of wire within vacuum to ensure the maximum insulation temperature is not exceeded. For 20 AWG wire, these operating parameters are: 3.7 amps per wire, bundle of 15 or more wires, 70 C environment, and vacuum of 10(exp -5) torr or less. To determine the behavior and temperature of electrical wire at different operating conditions, a thermal vacuum test was performed on a representative electrical harness of the Hubble Space Telescope (HST) power distribution system. This paper describes the test and the results.

  10. A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

    SciTech Connect

    Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Steigerwald, Robert L; Sabate, Juan A; Chi, Song; McCann, Adam J; Zhang, Li; Mueller, Frank

    2012-09-01

    In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

  11. Flight test experience with the F-8 digital fly-by-wire system

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.

    1975-01-01

    Flight test results of the F-8 digital fly-by-wire (DFBW) control system are presented and the implications for application to active control technology (ACT) are discussed. The F-8 DFBW system has several of the attributes of proposed ACT systems, so the flight test experience is helpful in assessing the capabilities of those systems. Topics of discussion include the predicted and actual flight performance of the control system, assessments of aircraft flying qualities and other piloting factors, software management and control, and operational experience.

  12. Flight test experience with the F-8 digital fly-by-wire system

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.

    1976-01-01

    Flight test results of the F-8 digital fly by wire control system are presented and the implications for application to active control technology are discussed. The F-8 DFBW system has several of the attributes of proposed ACT systems, so the flight test experience is helpful in assessing the capabilities of those systems. Topics of discussion include the predicted and actual flight performance of the control system, assessments of aircraft flying qualities and other piloting factors, software management and control, and operational experience.

  13. Detection of High-impedance Arcing Faults in Radial Distribution DC Systems

    NASA Technical Reports Server (NTRS)

    Gonzalez, Marcelo C.; Button, Robert M.

    2003-01-01

    High voltage, low current arcing faults in DC power systems have been researched at the NASA Glenn Research Center in order to develop a method for detecting these 'hidden faults', in-situ, before damage to cables and components from localized heating can occur. A simple arc generator was built and high-speed and low-speed monitoring of the voltage and current waveforms, respectively, has shown that these high impedance faults produce a significant increase in high frequency content in the DC bus voltage and low frequency content in the DC system current. Based on these observations, an algorithm was developed using a high-speed data acquisition system that was able to accurately detect high impedance arcing events induced in a single-line system based on the frequency content of the DC bus voltage or the system current. Next, a multi-line, radial distribution system was researched to see if the arc location could be determined through the voltage information when multiple 'detectors' are present in the system. It was shown that a small, passive LC filter was sufficient to reliably isolate the fault to a single line in a multi-line distribution system. Of course, no modification is necessary if only the current information is used to locate the arc. However, data shows that it might be necessary to monitor both the system current and bus voltage to improve the chances of detecting and locating high impedance arcing faults

  14. Modeling of Steer-by-Wire System Used in New Braking Handwheel Concept

    NASA Astrophysics Data System (ADS)

    Messaoudène, K.; Oufroukh, N. Ait; Mammar, S.

    2008-06-01

    The handwheel is one of the primary control mechanisms of automobile thus interaction between the handwheel and the driver is critical to safety. The driver applies forces that direct the vehicle while the handwheel communicates feedback information to the driver of the forces experience by the car within its environment. The handwheel also provides a predictable mechanical feel to the driver to allow smooth and safe control. Many researchers tried to reproduce this feeling by creating steer-by-wire systems. This paper explores this new concept of handwheel and it describes the modeling steps of the components including the restitution mechanism for force feedback and its various links with the vehicle lateral dynamics and the pneumatic contacts. The aim is to explore the possibility to combine a braking device within the steer-by-wire system in order to provide a more suitable and ergonomic device to the driver.

  15. Comparative study of reference currents and DC bus voltage control for Three-Phase Four-Wire Four-Leg SAPF to compensate harmonics and reactive power with 3D SVM.

    PubMed

    Chebabhi, A; Fellah, M K; Kessal, A; Benkhoris, M F

    2015-07-01

    In this paper the performances of three reference currents and DC bus voltage control techniques for Three-Phase Four-Wire Four-Leg SAPF are compared for balanced and unbalanced load conditions. The main goals are to minimize the harmonics, reduce the magnitude of neutral current, eliminate the zero-sequence current components caused by single-phase nonlinear loads and compensate the reactive power, and on the other hand improve performances such as robustness, stabilization, trajectory pursuit, and reduce time response. The three techniques are analyzed mathematically and simulation results are compared. The techniques considered for comparative study are the PI Control, Sliding Mode Control and the Backstepping Control. Synchronous reference frame theory (SRF) in the dqo-axes is used to generate the reference currents, of the inverter. PMID:25704056

  16. Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

    NASA Astrophysics Data System (ADS)

    Béthoux, O.; Cathelin, J.

    2010-12-01

    Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the

  17. Development of a system based on open source technology for DC resistor calibration

    NASA Astrophysics Data System (ADS)

    Geronymo, G. M.; Silva, M. C.

    2016-07-01

    This work present the development of a new system, based on open source technology, for the automation of DC resistor calibration. The new system is web-based, stores the measurement registers on a structured database and has new features that can increase the productivity of the laboratory. Some proposes of future development are presented, also.

  18. Low-Cost Undergraduate Control Systems Experiments Using Microcontroller-Based Control of a DC Motor

    ERIC Educational Resources Information Center

    Gunasekaran, M.; Potluri, R.

    2012-01-01

    This paper presents low-cost experiments for a control systems laboratory module that is worth one and a third credits. The experiments are organized around the microcontroller-based control of a permanent magnet dc motor. The experimental setups were built in-house. Except for the operating system, the software used is primarily freeware or free…

  19. THE TRACK SYSTEM IN WASHINGTON, D.C.

    ERIC Educational Resources Information Center

    BLACKE, EVIAS, JR.

    THE FOUR AREAS PRESENTED ARE GROUP AND INDIVIDUAL INTELLIGENCE TESTS, ACHIEVEMENT TESTS, EDUCATIONAL GROUPING PROCEDURES, AND FACTORS ASSOCIATED WITH LOW INCOME. A TRACK SYSTEM, OR ANY SYSTEM OF GROUPING, SHOULD PROMOTE RATHER THAN HINDER THE ACHIEVEMENT OF BOTH THE LOW-INCOME GROUPS AND THE HIGHER-INCOME GROUPS. THE PRESENT TRACK SYSTEM IN…

  20. Description of the SSF PMAD DC testbed control system data acquisition function

    NASA Technical Reports Server (NTRS)

    Baez, Anastacio N.; Mackin, Michael; Wright, Theodore

    1992-01-01

    The NASA LeRC in Cleveland, Ohio has completed the development and integration of a Power Management and Distribution (PMAD) DC Testbed. This testbed is a reduced scale representation of the end to end, sources to loads, Space Station Freedom Electrical Power System (SSF EPS). This unique facility is being used to demonstrate DC power generation and distribution, power management and control, and system operation techniques considered to be prime candidates for the Space Station Freedom. A key capability of the testbed is its ability to be configured to address system level issues in support of critical SSF program design milestones. Electrical power system control and operation issues like source control, source regulation, system fault protection, end-to-end system stability, health monitoring, resource allocation, and resource management are being evaluated in the testbed. The SSF EPS control functional allocation between on-board computers and ground based systems is evolving. Initially, ground based systems will perform the bulk of power system control and operation. The EPS control system is required to continuously monitor and determine the current state of the power system. The DC Testbed Control System consists of standard controllers arranged in a hierarchical and distributed architecture. These controllers provide all the monitoring and control functions for the DC Testbed Electrical Power System. Higher level controllers include the Power Management Controller, Load Management Controller, Operator Interface System, and a network of computer systems that perform some of the SSF Ground based Control Center Operation. The lower level controllers include Main Bus Switch Controllers and Photovoltaic Controllers. Power system status information is periodically provided to the higher level controllers to perform system control and operation. The data acquisition function of the control system is distributed among the various levels of the hierarchy. Data

  1. Monitoring of debris flows and landslides by wired and wireless systems. Experiences from the Catalan Pyrenees.

    NASA Astrophysics Data System (ADS)

    Hürlimann, Marcel; Abancó, Clàudia; Moya, José; Vilajosana, Ignasi; Llosa, Jordi

    2013-04-01

    Sophisticated monitoring of landslides for research purpose has started in the 1990thies in the Catalan Pyrenees. Since then several types of mass movements (large landslides, debris flows, shallow landslides and rock falls) and multiples techniques have been applied. In this contribution, special attention will be given to the debris-flow monitoring system installed since summer 2009 in the Rebaixader catchment, Central Pyrenees. The monitoring system has continuously been improved during the last years and nowadays includes devices studying the three major aspects: 1) initiation, 2) flow dynamics, and 3) accumulation. While some parts of the monitoring network include a traditional wired system, the newer parts were installed using low-power wireless devices. Two major aspects will be discussed. First, results of the Rebaixader monitoring site will be presented. Second, experience regarding the monitoring will be evaluated focussing on technical aspects and the comparison between wired and wireless techniques. In the Rebaixader catchment, 6 debris flows and 11 debris floods were observed between August 2009 and October 2012. Surprisingly, also 4 major rock falls were recorded. The rainfall analysis shows that the debris flows were triggered by short, high-intensity rainstorms with a preliminary threshold of about 15 mm during 1 hour. In addition, there was observed a positive trend between event volume and rainfall amount or intensity. The analysis of the ground vibration signals shows significant differences between the time series recorded at the different geophones. These differences are associated with the geophone location in the channel (distance and material), the mounting or the data acquisition system. For instance, the most downstream geophone, installed in bedrock, shows the clearest debris-flows vibration time series, while the uppermost is the most reliable regarding the detection of rockfalls. An evaluation of wired versus wireless monitoring

  2. NASA/BAE Systems SpaceWire Efforts

    NASA Technical Reports Server (NTRS)

    Rakow, Glenn Parker; Schnurr, Richard G.; Kapcio, Paul

    2003-01-01

    This paper discusses the state of the NASA and BAE SYSTEMS developments using Spacewire. NASA has developed intellectual property that implements Spacewire in Register Transfer Level VHDL for a Spacewire link and router. This design has been extensively verified using directed tests from the Spacewire Standard and design specification, as well as being randomly tested to flush out hard to find bugs in the code. The high level features of the design will be discussed, including the support for multiple time code masters, which will be useful for the James Webb Space Telescope electrical architecture. This design is now ready to be targeted to FPGA's and ASICs. Target utilization and performance information will be presented for some spaceflight qualified FPGA's and a discussion of the ASIC implementations will be addressed. In particular, the BAE SYSTEMS ASIC will be highlighted which will be implemented in their 0.25 micron rad-hard line. The chip will implement a 4-port router with the ability to tie chips together to make larger routers without external glue logic. This part will have integrated LVDS driver/receivers, include a PLL and include skew control logic. It will be targeted to run at greater than 300 MHz and include the implementation for the proposed Spacewire transport layer. The need to provide a reliable transport mechanism for Spacewire has been identified by both NASA and ESA, who are attempting to define a transport layer standard that utilizes a low overhead, low latency connection oriented approach. The Transport layer needs to be implemented in hardware-to prevent bottlenecks.

  3. 49 CFR 234.241 - Protection of insulated wire; splice in underground wire.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... underground wire. 234.241 Section 234.241 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM SAFETY... of insulated wire; splice in underground wire. Insulated wire shall be protected from...

  4. 49 CFR 234.241 - Protection of insulated wire; splice in underground wire.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... underground wire. 234.241 Section 234.241 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM SAFETY... of insulated wire; splice in underground wire. Insulated wire shall be protected from...

  5. Permanent Magnet DC Motor Sliding Mode Control System

    NASA Astrophysics Data System (ADS)

    Vaez-Zadeh, S.; Zamanian, M.

    2000-09-01

    In this paper a sliding mode controller (SMC) is designed for a permanent magnet, direct current (PMDC) motor to enhance the motor performance in the presence of unwanted uncertainties. Both the electrical and mechanical signals are used as the inputs to the SMC. The complete motor control system is simulated on a personal computer with different design parameters and desirable system performance is obtained. The experimental implementation of the motor control system is also presented. The test results confirm the simulation results and validate the proposed control system.

  6. Intelligent electrical harness connector assembly using Bell Helicopter Textron's 'Wire Harness Automated Manufacturing System'

    NASA Astrophysics Data System (ADS)

    Springer, D. W.

    Bell Helicopter Textron, Incorporated (BHTI) installed two Digital Equipment Corporation PDP-11 computers and an American Can Inc. Ink Jet printer in 1980 as the cornerstone of the Wire Harness Automated Manufacturing System (WHAMS). WHAMS is based upon the electrical assembly philosophy of continuous filament harness forming. This installation provided BHTI with a 3 to 1 return-on-investment by reducing wire and cable identification cycle time by 80 percent and harness forming, on dedicated layout tooling, by 40 percent. Yet, this improvement in harness forming created a bottle neck in connector assembly. To remove this bottle neck, BHTI has installed a prototype connector assembly cell that integrates the WHAMS' data base and innovative computer technologies to cut harness connector assembly cycle time. This novel connector assembly cell uses voice recognition, laser identification, and animated computer graphics to help the electrician in the correct assembly of harness connectors.

  7. SpaceWire-based thermal-infrared imager system for asteroid sample return mission HAYABUSA2

    NASA Astrophysics Data System (ADS)

    Hihara, Hiroki; Iwase, Kaori; Sano, Junpei; Otake, Hisashi; Okada, Tatsuaki; Funase, Ryu; Kashikawa, Ryoichi; Higashino, Isamu; Masuda, Tetsuya

    2014-01-01

    A thermal-infrared (TIR) imager system is developed for HAYABUSA2, which is planned to be launched in 2014 and aims at sample-return from a C-class near-Earth asteroid 162173 (1999JU3) considered to contain organic or hydrated materials. The system consists of a TIR imager and digital electronics, which are used not only for the scientific investigation of physical properties of the asteroid surface, but also for the assessment of landing site selection and safe descent operation onto the asteroid surface with in situ measurement. TIR adopts an uncooled bolometer. Image operations such as multiple images summation, dark image subtraction, and the compensation of dead pixels are processed onboard. A processing module is connected to sensor interfaces through SpaceWire in order to provide deterministic processing time. Data compression is also provided to reduce the restriction of transmission time, which provides the equivalent compression ratio as JPEG2000 in 1/30 processing time in average. A high-speed data recorder is connected through SpaceWire in order to record TIR data in parallel with other sensor data. The modularity of SpaceWire enables us to use these as built devices for TIR and inherits the same design as the long-wavelength infrared imager developed for the Venus climate orbiter Akatsuki.

  8. Design and test experience with a triply redundant digital fly-by-wire control system

    NASA Technical Reports Server (NTRS)

    Szalai, K. J.; Felleman, P. G.; Gera, J.; Glover, R. D.

    1976-01-01

    A triplex digital fly-by-wire flight control system was developed and then installed in a NASA F-8C aircraft to provide fail-operative, full authority control. Hardware and software redundancy management techniques were designed to detect and identify failures in the system. Control functions typical of those projected for future actively controlled vehicles were implemented. This paper describes the principal design features of the system, the implementation of computer, sensor, and actuator redundancy management, and the ground test results. An automated test program to verify sensor redundancy management software is also described.

  9. Annular suspension and pointing system with controlled DC electromagnets

    NASA Technical Reports Server (NTRS)

    Vu, Josephine Lynn; Tam, Kwok Hung

    1993-01-01

    The Annular Suspension and Pointing System (ASPS) developed by the Flight System division of Sperry Corporation is a six-degree of freedom payload pointing system designed for use with the space shuttle. This magnetic suspension and pointing system provides precise controlled pointing in six-degrees of freedom, isolation of payload-carrier disturbances, and end mount controlled pointing. Those are great advantages over the traditional mechanical joints for space applications. In this design, we first analyzed the assumed model of the single degree ASPS bearing actuator and obtained the plant dynamics equations. By linearizing the plant dynamics equations, we designed the cascade and feedback compensators such that a stable and satisfied result was obtained. The specified feedback compensator was computer simulated with the nonlinearized plant dynamics equations. The results indicated that an unstable output occurred. In other words, the designed feedback compensator failed. The failure of the design is due to the Taylor's series expansion not converging.

  10. Research study on multi-KW DC distribution system

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.

    1975-01-01

    Power distribution system noise and transient stress on switchgear in large space vehicle power systems were investigated in terms of the effect of flight designs of long power distribution cables on load interface EMI requirements. A fifty meter cable pair was simulated to study interactions between the cable, load, and power source terminations. Power system noise characteristics were evaluated based on current spacecraft data, interface hardware filter designs, and power cable parameters. Parametric approaches were defined for evaluating switching transients at various distribution voltage levels. It is concluded that the state-of-the-art semiconductor switches represent a viable approach toward the implementation of power system design with distribution voltages of 120 VDC or less. The interface definition and design for the bus control unit was updated to be consistent with the established requirements.

  11. Power system monitoring and source control of the Space Station Freedom DC power system testbed

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.; Baez, Anastacio N.

    1992-01-01

    Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the DC Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

  12. Power system monitoring and source control of the Space Station Freedom dc-power system testbed

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.; Baez, Anastacio N.

    1992-01-01

    Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the dc Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

  13. Design and construction evaluation of a photovoltaic DC LED lighting system

    NASA Astrophysics Data System (ADS)

    Bhamidipati, Jyotsna

    2008-08-01

    The market demand for commercialization of Photovoltaic (PV) systems depends a lot on the reliability, efficiency and performance of various components within the system. PV panels produce DC power when exposed to sunlight, and an inverter converts this to AC power in a typical solar powered building. Though, PV lighting has existed for a long time it hasn't been very effective, as incandescent light sources were commonly used which are inefficient. Today fluorescent fixtures are mostly used with PV's due to its high efficacy. Light-emitting diodes present a new vision to energy efficiency in lighting design with their low energy consumption. Current research predicts improved efficiencies of LED light fixtures and their commercial use is a few years away. LEDs which operate on DC voltages when coupled with photovoltaics can be a simple PV lighting application and a sustainable solution with potential for payback. This research evaluates the design and construction of a photovoltaic DC LED lighting system for a solar house at Pennsylvania State University. A detailed cost and payback analysis of a PV DC LED lighting system is presented in this research. PV output simulations for the solar house are presented. Results presented in this research indicate that the Solid state lighting market is evolving rapidly and that LED's are a choice in stand-alone photovoltaic DC lighting systems. The efficiency and the cost-effectiveness of such systems would however improve in the coming years with research and development now focused on PV systems and on Solid state lighting technologies.

  14. Prospects of long-distance HTS DC power transmission systems

    NASA Astrophysics Data System (ADS)

    Romashov, M. A.; Sytnikov, V. E.; Shakarian, Y. G.; Ivanov, Y. V.

    2014-05-01

    Continual improvement of technologies for the safe use of power resources is a key to sustainable development of a human society. In particular, high-temperature superconductivity (HTS) should be used to meet the growing needs of the electric-power industry. It is known that HTS power cables allow us to increase the level of transmitted energy to several GW at voltage of 66-110 kV. HTS power cables of a coaxial design are almost ideal non-polluting system shielding electromagnetic field. In the present work we have tried to analyze various configurations of HTS power transmission systems, estimate the cable transmission capacitance depending on distance, and characterize reliability and efficiency of the systems.

  15. The state-of-the-art of dc power distribution systems/components for space applications

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.

    1988-01-01

    This report is a survey of the state of the art of high voltage dc systems and components. This information can be used for consideration of an alternative secondary distribution (120 Vdc) system for the Space Station. All HVdc components have been prototyped or developed for terrestrial, aircraft, and spacecraft applications, and are applicable for general space application with appropriate modification and qualification. HVdc systems offer a safe, reliable, low mass, high efficiency and low EMI alternative for Space Station secondary distribution.

  16. Software Development for a CompactRIO-Based Wire Scanner Control and Data Acquisition SYstem

    SciTech Connect

    Sedillo, James Daniel

    2012-05-16

    The Beam Diagnostics and Instrumentation Team at the Los Alamos Neutron Science Center is developing a wire scanner data acquisition and control system with a National Instrument's compactRIO at its core. For this application, the compactRIO controller not only requires programming the FPGA and RT computer internal to the compactRIO, but also requires programming a client computer and a touch panel display. This article will summarize the hardware interfaces and describe the software design approach utilized for programming and interfacing the four systems together in order to fulfill the design requirements and promote reliable interoperability.

  17. Basic Wiring.

    ERIC Educational Resources Information Center

    Kaltwasser, Stan; And Others

    This module is the first in a series of three wiring publications; it serves as the foundation for students enrolled in a wiring program. It is a prerequisite to either "Residential Wiring" or "Commercial and Industrial Wiring." The module contains 16 instructional units that cover the following topics: occupational introduction; general safety;…

  18. SpaceWire- Based Control System Architecture for the Lightweight Advanced Robotic Arm Demonstrator [LARAD

    NASA Astrophysics Data System (ADS)

    Rucinski, Marek; Coates, Adam; Montano, Giuseppe; Allouis, Elie; Jameux, David

    2015-09-01

    The Lightweight Advanced Robotic Arm Demonstrator (LARAD) is a state-of-the-art, two-meter long robotic arm for planetary surface exploration currently being developed by a UK consortium led by Airbus Defence and Space Ltd under contract to the UK Space Agency (CREST-2 programme). LARAD has a modular design, which allows for experimentation with different electronics and control software. The control system architecture includes the on-board computer, control software and firmware, and the communication infrastructure (e.g. data links, switches) connecting on-board computer(s), sensors, actuators and the end-effector. The purpose of the control system is to operate the arm according to pre-defined performance requirements, monitoring its behaviour in real-time and performing safing/recovery actions in case of faults. This paper reports on the results of a recent study about the feasibility of the development and integration of a novel control system architecture for LARAD fully based on the SpaceWire protocol. The current control system architecture is based on the combination of two communication protocols, Ethernet and CAN. The new SpaceWire-based control system will allow for improved monitoring and telecommanding performance thanks to higher communication data rate, allowing for the adoption of advanced control schemes, potentially based on multiple vision sensors, and for the handling of sophisticated end-effectors that require fine control, such as science payloads or robotic hands.

  19. Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Appelbaum, Joseph; Singer, S.

    1989-01-01

    Direct current (dc) motors are used in terrestrial photovoltaic (PV) systems such as in water-pumping systems for irrigation and water supply. Direct current motors may also be used for space applications. Simple and low weight systems including dc motors may be of special interest in space where the motors are directly coupled to the solar cell array (with no storage). The system will operate only during times when sufficient insolation is available. An important performance characteristic of electric motors is the starting to rated torque ratio. Different types of dc motors have different starting torque ratios. These ratios are dictated by the size of solar cell array, and the developed motor torque may not be sufficient to overcome the load starting torque. By including a maximum power point tracker (MPPT) in the PV system, the starting to rated torque ratio will increase, the amount of which depends on the motor type. The starting torque ratio is calculated for the permanent magnet, series and shunt excited dc motors when powered by solar cell arrays for two cases: with and without MPPT's. Defining a motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 was obtained for the permanent magnet motor and a magnification of 7 for both the series and shunt motors. The effect of the variation of solar insolation on the motor starting torque was covered. All motor types are less sensitive to insolation variation in systems including MPPT's as compared to systems with MPPT's. The analysis of this paper will assist the PV system designed to determine whether or not to include an MPPT in the system for a specific motor type.

  20. Texture development in Galfenol wire

    NASA Astrophysics Data System (ADS)

    Boesenberg, A. J.; Restorff, J. B.; Wun-Fogle, M.; Sailsbury, H.; Summers, E.

    2013-05-01

    Galfenol (Fe-Ga alloy) wire fabrication provides a low cost alternative to directional solidification methods. This work evaluates the compositional dependence of the wire drawing suitability of Fe-Ga and characterizes the microstructural and magnetic properties of these wires. Wire has been produced with Ga contents between 10 at. % and 17 at. % to allow determination of the ductile to brittle transition (DTBT) in wire manufacture. Published results on chill cast bend specimens indicated that a DTBT occurs at roughly 15 at. % Ga. This DTBT was observed under tensile loading with a corresponding change in fracture behavior from transverse fracture to intergranular fracture. For improved magnetostrictive performance, higher Ga contents are desired, closer to the 17 at. % Ga evaluated in this work. Electron backscattered diffraction B-H loop and resonance measurements as a function of magnetic field (to determine modulus and coupling factor) are presented for as-drawn, furnace, and direct current (DC) annealed wire. Galfenol wire produced via traditional drawing methods is found to have a strong <110> (α) texture parallel to the drawing direction. As-drawn wire was observed to have a lower magnetic permeability and larger hysteresis than DC annealed wire. This is attributed to the presence of a large volume of crystalline defects; such as vacancies and dislocations.

  1. Two-level system dynamics in amorphous dielectrics probed with a dc electric field

    NASA Astrophysics Data System (ADS)

    Khalil, Moe; Gladchenko, Sergiy; Stoutimore, M. J. A.; Wellstood, F. C.; Osborn, K. D.

    2012-02-01

    We report loss in a thin-film dc electric-field tunable LC resonator built with superconducting aluminum and silicon nitride dielectric. To measure the loss we continually apply microwave power on resonance and monitor the transmitted power. At milli-Kelvin temperatures, loss is limited by two-level systems in the dielectric which are saturated with high microwave excitation power. Measurements show that a sudden change of applied dc field causes the dielectric loss to increase to the intrinsic low power loss tangent of the dielectric. We study the subsequent relaxation of the loss tangent caused by two-level system saturation and interactions. We discuss how this arises from the dynamics of a distribution of two-level system defects and compare it with new theoretical work on interacting two-level systems.

  2. Preliminary system design study for a digital fly-by-wire flight control system for an F-8C aircraft

    NASA Technical Reports Server (NTRS)

    Seacord, C. L.; Vaughn, D. K.

    1976-01-01

    The design of a fly-by-wire control system having a mission failure probability of less than one millionth failures per flight hour is examined. Emphasis was placed on developing actuator configurations that would improve the system performance, and consideration of the practical aspects of sensor/computer and computer/actuator interface implementation. Five basic configurations were defined as appropriate candidates for the F-8C research aircraft. Options on the basic configurations were included to cover variations in flight sensors, redundancy levels, data transmission techniques, processor input/output methods, and servo actuator arrangements. The study results can be applied to fly by wire systems for transport aircraft in general and the space shuttle.

  3. Description and Flight Test Results of the NASA F-8 Digital Fly-by-Wire Control System

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A NASA program to develop digital fly-by-wire (DFBW) technology for aircraft applications is discussed. Phase I of the program demonstrated the feasibility of using a digital fly-by-wire system for aircraft control through developing and flight testing a single channel system, which used Apollo hardware, in an F-8C airplane. The objective of Phase II of the program is to establish a technology base for designing practical DFBW systems. It will involve developing and flight testing a triplex digital fly-by-wire system using state-of-the-art airborne computers, system hardware, software, and redundancy concepts. The papers included in this report describe the Phase I system and its development and present results from the flight program. Man-rated flight software and the effects of lightning on digital flight control systems are also discussed.

  4. Optimal Design of Litz Wire Coils With Sandwich Structure Wirelessly Powering an Artificial Anal Sphincter System.

    PubMed

    Ke, Lei; Yan, Guozheng; Yan, Sheng; Wang, Zhiwu; Li, Xiaoyang

    2015-07-01

    Transcutaneous energy transfer system (TETS) is widely used to energize implantable biomedical devices. As a key part of the TETS, a pair of applicable coils with low losses, high unloaded Q factor, and strong coupling is required to realize an efficient TETS. This article presents an optimal design methodology of planar litz wire coils sandwiched between two ferrite substrates wirelessly powering a novel mechanical artificial anal sphincter system for treating severe fecal incontinence, with focus on the main parameters of the coils such as the wire diameter, number of turns, geometry, and the properties of the ferrite substrate. The theoretical basis of optimal power transfer efficiency in an inductive link was analyzed. A set of analytical expressions are outlined to calculate the winding resistance of a litz wire coil on ferrite substrate, taking into account eddy-current losses, including conduction losses and induction losses. Expressions that describe the geometrical dimension dependence of self- and mutual inductance are derived. The influence of ferrite substrate relative permeability and dimensions is also considered. We have used this foundation to devise an applicable coil design method that starts with a set of realistic constraints and ends with the optimal coil pair geometries. All theoretical predictions are verified with measurements using different types of fabricated coils. The results indicate that the analysis is useful for optimizing the geometry design of windings and the ferrite substrate in a sandwich structure as part of which, in addition to providing design insight, allows speeding up the system efficiency-optimizing design process. PMID:25808086

  5. Nonlinear control of voltage source converters in AC-DC power system.

    PubMed

    Dash, P K; Nayak, N

    2014-07-01

    This paper presents the design of a robust nonlinear controller for a parallel AC-DC power system using a Lyapunov function-based sliding mode control (LYPSMC) strategy. The inputs for the proposed control scheme are the DC voltage and reactive power errors at the converter station and the active and reactive power errors at the inverter station of the voltage-source converter-based high voltage direct current transmission (VSC-HVDC) link. The stability and robust tracking of the system parameters are ensured by applying the Lyapunov direct method. Also the gains of the sliding mode control (SMC) are made adaptive using the stability conditions of the Lyapunov function. The proposed control strategy offers invariant stability to a class of systems having modeling uncertainties due to parameter changes and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances like changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses for single generating system connected to the power grid in a single machine infinite-bus AC-DC network and also for a 3-machine two-area power system. Furthermore, a second order super twisting sliding mode control scheme has been presented in this paper that provides a higher degree of nonlinearity than the LYPSMC and damps faster the converter and inverter voltage and power oscillations. PMID:24906895

  6. A study of some features of ac and dc electric power systems for a space station

    NASA Technical Reports Server (NTRS)

    Hanania, J. I.

    1983-01-01

    This study analyzes certain selected topics in rival dc and high frequency ac electric power systems for a Space Station. The interaction between the Space Station and the plasma environment is analyzed, leading to a limit on the voltage for the solar array and a potential problem with resonance coupling at high frequencies. Certain problems are pointed out in the concept of a rotary transformer, and further development work is indicated in connection with dc circuit switching, special design of a transmission conductor for the ac system, and electric motors. The question of electric shock hazards, particularly at high frequency, is also explored. and a problem with reduced skin resistance and therefore increased hazard with high frequency ac is pointed out. The study concludes with a comparison of the main advantages and disadvantages of the two rival systems, and it is suggested that the choice between the two should be made after further studies and development work are completed.

  7. Wind-powered asynchronous AC/DC/AC converter system. [for electric power supply regulation

    NASA Technical Reports Server (NTRS)

    Reitan, D. K.

    1973-01-01

    Two asynchronous ac/dc/ac systems are modelled that utilize wind power to drive a variable or constant hertz alternator. The first system employs a high power 60-hertz inverter tie to the large backup supply of the power company to either supplement them from wind energy, storage, or from a combination of both at a preset desired current; rectifier and inverter are identical and operate in either mode depending on the silicon control rectifier firing angle. The second system employs the same rectification but from a 60-hertz alternator arrangement; it provides mainly dc output, some sinusoidal 60-hertz from the wind bus and some high harmonic content 60-hertz from an 800-watt inverter.

  8. Stability of large DC power systems using switching converters, with application to the International Space Station

    SciTech Connect

    Gholdston, E.W.; Karimi, K.; Lee, F.C.; Rajagopalan, J.; Panov, Y.; Manners, B.

    1996-12-31

    As space direct current (dc) power systems continue to grow in size, switching power converters are playing an ever larger role in power conditioning and control. When designing a large dc system using power converters are playing an ever larger role in power conditioning and control.When designing a large dc system using power converters of this type, special attention must be placed on the electrical stability of the system and of the individual loads on the system. In the design of the electric power system (EPS) of the International Space Station (ISS), the National Aeronautics and Space Administration (NASA) and its contractor team led by Boeing Defense and Space Group has placed a great deal of emphasis on designing for system and load stability. To achieve this goal, the team has expended considerable effort deriving a clear concept on defining system stability in both a general sense and specifically with respect to the space station. The ISS power system presents numerous challenges with respect to system stability, such as high power, complex sources and undefined loads. As a result, the program has derived an impedance specification approach for system stability. This approach is based on the significant relationship between source and load impedances and the effect of this relationship on system stability. This approach is limited in its applicability by the theoretical and practical limits on component designs as presented by each system segment. As a result, the overall approach to system stability implemented by the ISS program consists of specific hardware requirements coupled with extensive system analysis and hardware testing.

  9. Brushless DC motor control system responsive to control signals generated by a computer or the like

    NASA Technical Reports Server (NTRS)

    Packard, Douglas T. (Inventor); Schmitt, Donald E. (Inventor)

    1987-01-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The rotor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor may be regulated by applying a separate control signal to each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  10. Brushless DC motor control system responsive to control signals generated by a computer or the like

    NASA Technical Reports Server (NTRS)

    Packard, D. T. (Inventor)

    1985-01-01

    A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The motor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor be regulated by applying a separate control signal and each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

  11. The SpaceWire-based thermal infrared imager system for asteroid sample return mission HAYABUSA2

    NASA Astrophysics Data System (ADS)

    Otake, Hisashi; Okada, Tatsuaki; Funase, Ryu; Hihara, Hiroki; Sano, Junpei; Iwase, Kaori; Kashikawa, Ryoichi; Higashino, Isamu; Masuda, Tetsuya

    2013-09-01

    Thermal infrared imager system is developed for HAYABUSA2, which is planned to be launched in 2014 and aims at sample-return from a C class near-Earth asteroid 1999JU3 considered to contain organic or hydrated materials. The system consists of a thermal-infrared imager (TIR) and a digital electronics, which is used not only for the scientific investigation of physical properties of the asteroid surface, but also for the assessment of landing site selection and safe descent operation onto the asteroid surface with in situ measurement. Since round trip communication time between the asteroid and the Earth is more than thirty minutes, onboard automatic data processing function and high speed data recording capability are provided to exploit the limited downlink capacity which is up to 32kbps. TIR adopts an uncooled bolometer with 320 x 240 effective pixels. Image operations as multiple images summation, dark image subtraction, and the compensation of dead pixels are processed onboard. A processing module is connected to sensor interfaces through SpaceWire in order to provide deterministic processing time. Data compression is also provided to reduce restriction on storage capacity and operation time, which provides the equivalent compression ratio as JPEG2000 in 1/30 processing time in average. A high speed data recorder is also connected through SpaceWire in 50Mbps in order to record TIR data in parallel with other sensor data. The modularity of SpaceWire enables to use as built devices for TIR and inherits the same design as the long-wavelength infrared imager developed for the Venus climate orbiter Akatsuki.

  12. High-conductive organometallic molecular wires with delocalized electron systems strongly coupled to metal electrodes.

    PubMed

    Schwarz, Florian; Kastlunger, Georg; Lissel, Franziska; Riel, Heike; Venkatesan, Koushik; Berke, Heinz; Stadler, Robert; Lörtscher, Emanuel

    2014-10-01

    Besides active, functional molecular building blocks such as diodes or switches, passive components, for example, molecular wires, are required to realize molecular-scale electronics. Incorporating metal centers in the molecular backbone enables the molecular energy levels to be tuned in respect to the Fermi energy of the electrodes. Furthermore, by using more than one metal center and sp-bridging ligands, a strongly delocalized electron system is formed between these metallic "dopants", facilitating transport along the molecular backbone. Here, we study the influence of molecule-metal coupling on charge transport of dinuclear X(PP)2FeC4Fe(PP)2X molecular wires (PP = Et2PCH2CH2PEt2); X = CN (1), NCS (2), NCSe (3), C4SnMe3 (4), and C2SnMe3 (5) under ultrahigh vacuum and variable temperature conditions. In contrast to 1, which showed unstable junctions at very low conductance (8.1 × 10(-7) G0), 4 formed a Au-C4FeC4FeC4-Au junction 4' after SnMe3 extrusion, which revealed a conductance of 8.9 × 10(-3) G0, 3 orders of magnitude higher than for 2 (7.9 × 10(-6) G0) and 2 orders of magnitude higher than for 3 (3.8 × 10(-4) G0). Density functional theory (DFT) confirmed the experimental trend in the conductance for the various anchoring motifs. The strong hybridization of molecular and metal states found in the C-Au coupling case enables the delocalized electronic system of the organometallic Fe2 backbone to be extended over the molecule-metal interfaces to the metal electrodes to establish high-conductive molecular wires. PMID:25233125

  13. Distributed image processing system for the monitoring of hot steel wire

    NASA Astrophysics Data System (ADS)

    O'Leary, Paul; Weiss, Michael; Schiller, Arnulf

    2003-05-01

    In a prototype for monitoring hot steel wire different technologies are integrated to achieve a robust, flexibly configurable and scalable imaging system. It is designed as a distributed system with private network and Tuplespace communication implementable on a LINUX Server. Intelligent cameras grab and process the image data. For real time communication between the cameras and standard industrial I/O-modules (IEC-61131) MODBUS/TCP messaging is applied. A switch with integrated firewall makes services available to the supervisory control system. Results are available as XML-logfiles. The image processing defines the upper and lower edges of the material by minimum/maximum filtering of the y-gradient. Dual Grassmanian coordinates are used to fit two parallel lines to the edge points by singular value decomposition. This gives the distance between the lines and the confidence interval of each measurement simultaneously, whereas latter is used to reject poor data. Changes of the distance are analysed computing local central moments. Presently, 12 images per second are acquired. The application is able to detect spontaneous rotation of the wire around the axis of rolling directly at the rolling stands and treats also poor images (due to steam of cooling water). It indicates resulting defects, which may go undetected otherwise.

  14. Pose measurement base on machine vision for the aircraft model in wire-driven parallel suspension system

    NASA Astrophysics Data System (ADS)

    Chen, Yi-feng; Wu, Liao-ni; Yue, Sui-lu; Lin, Qi

    2013-03-01

    In wind tunnel tests, the pose of the aircraft model in wire-driven parallel suspension system (WDPSS) is determined by driving several wires. Pose measurement is very important for the study of WDPSS. Using machine vision technology, Monocular Vision Measurement System has been constructed to estimate the pose of the aircraft model by applying a camera calibration, by extracting corresponding control points for the aircraft model, and by applying several homogeneous transformations. This article describes the programs of the measurement system, measurement principle and data processing methods which is based on HALCON to achieve the Solution of the pose of aircraft model. Through experiments, practical feasibility of the system is validated.

  15. Characteristic Analysis of DC Electric Railway Systems with Superconducting Power Cables Connecting Power Substations

    NASA Astrophysics Data System (ADS)

    Ohsaki, H.; Matsushita, N.; Koseki, T.; Tomita, M.

    2014-05-01

    The application of superconducting power cables to DC electric railway systems has been studied. It could leads to an effective use of regenerative brake, improved energy efficiency, effective load sharing among the substations, etc. In this study, an electric circuit model of a DC feeding system is built and numerical simulation is carried out using MATLAB-Simulink software. A modified electric circuit model with an AC power grid connection taken into account is also created to simulate the influence of the grid connection. The analyses have proved that a certain amount of energy can be conserved by introducing superconducting cables, and that electric load distribution and concentration among the substations depend on the substation output voltage distribution.

  16. A one-wire battery monitoring system with applications to on-board charging for electric vehicles

    NASA Astrophysics Data System (ADS)

    Nowak, Dieter

    1990-10-01

    A on-board charge system which utilizes a one-wire system for voltage monitoring is discussed and test results obtained using the system are presented. The system consists of the following: (1) a 20 kHz high frequency charger; (2) a charge algorithm for lead-acid batteries with gelled electrolyte, such that gassing is avoided; (3) the control system to implement this charge algorithm; and (4) a one-wire battery monitoring system to provide cell/module voltage information to the battery charge controller. Prototype elements of the system have been tested and the system was installed into an EVA Pacer electric vehicle. Charge tests are performed and data taken with the system installed. All elements of the system functioned properly under user conditions. In particular, the charger demonstrated good efficiency, near unity power factor and full programmability. The charge controller functioned reliably and without flaw. The one-wire monitoring system which permits monitoring of cell/module voltages in a battery pack without an extensive conventional wire harness has proven effective and voltage measurements were taken fast enough for control of charging. It was found that for the purpose of voltage monitoring under driving conditions, the system in its present form is too slow.

  17. A one-wire'' battery monitoring system with applications to on-board charging for electric vehicles

    SciTech Connect

    Nowak, D. . Kenneth E. Johnson Research Center)

    1990-10-08

    A novel on-board charge system which utilizes a One-Wire'' system for voltage monitoring is discussed and test results obtained using the system are presented. The system consists of a 20 kHz high frequency charger, an algorithm for charging lead-acid batteries with gelled electrolyte, such that gassing is avoided, the control system to implement this charge algorithm and a one-wire battery monitoring system to provide cell/module voltage information to the battery charge controller. Prototype elements of the system have been tested and the system was installed into an EVA Pacer electric vehicle. Charge tests are performed and data taken with the system installed. All elements of the system functioned properly under user conditions. In particular, the charger demonstrated good efficiency, near unity power factor and full programmability. The charge controller functioned reliably and without flaw. The one-wire monitoring system which permits monitoring of cell/module voltages in a battery pack without an extensive conventional wire harness has proven effective and voltage measurements have taken fast enough for control of charging. It was found that for the purpose of voltage monitoring under driving conditions, the system in its present form is too slow.

  18. Front-end electronics and data acquisition system for a multi-wire 3D gas tracker

    NASA Astrophysics Data System (ADS)

    Łojek, K.; Rozpȩdzik, D.; Bodek, K.; Perkowski, M.; Severijns, N.

    2015-12-01

    This paper presents the design and implementation of the front-end electronics and the data acquisition (DAQ) system for readout of multi-wire drift chambers (MWDC). Apart of the conventional drift time measurement the system delivers the hit position along the wire utilizing the charge division technique. The system consists of preamplifiers, and analog and digital boards sending data to a back-end computer via an Ethernet interface. The data logging software formats the received data and enables an easy access to the data analysis software. The use of specially designed preamplifiers and peak detectors allows the charge-division readout of the low resistance signal wire. The implication of the charge-division circuitry onto the drift time measurement was studied and the overall performance of the electronic system was evaluated in dedicated off-line tests.

  19. Identification and adaptive neural network control of a DC motor system with dead-zone characteristics.

    PubMed

    Peng, Jinzhu; Dubay, Rickey

    2011-10-01

    In this paper, an adaptive control approach based on the neural networks is presented to control a DC motor system with dead-zone characteristics (DZC), where two neural networks are proposed to formulate the traditional identification and control approaches. First, a Wiener-type neural network (WNN) is proposed to identify the motor DZC, which formulates the Wiener model with a linear dynamic block in cascade with a nonlinear static gain. Second, a feedforward neural network is proposed to formulate the traditional PID controller, termed as PID-type neural network (PIDNN), which is then used to control and compensate for the DZC. In this way, the DC motor system with DZC is identified by the WNN identifier, which provides model information to the PIDNN controller in order to make it adaptive. Back-propagation algorithms are used to train both neural networks. Also, stability and convergence analysis are conducted using the Lyapunov theorem. Finally, experiments on the DC motor system demonstrated accurate identification and good compensation for dead-zone with improved control performance over the conventional PID control. PMID:21788017

  20. Surface and interface phonon-polaritons in freestanding quantum well wire systems of polar ternary mixed crystals

    NASA Astrophysics Data System (ADS)

    Yan, C. L.; Bao, J.; Yan, Z. W.

    2016-03-01

    The surface and interface phonon-polaritons in freestanding rectangular quantum well wire systems consisting of polar ternary mixed crystals are investigated in the modified random-element-isodisplacement model and the Born-Huang approximation, based on the Maxwell's equations with the boundary conditions. The numerical results of the surface and interface phonon-polariton frequencies as functions of the wave-vector, geometric structure, and the composition of the ternary mixed crystals in GaAs/AlxGa1-xAs and ZnxCd1-xSe/ZnSe quantum well wire systems are obtained and discussed. It is shown that there are 10 and 8 branches of surface and interface phonon-polaritons in the two quantum well wire systems respectively. The effects of the "two-mode" and "one-mode" behaviors of the ternary mixed crystals on the surface and interface phonon-polariton modes are shown in the dispersion curves.

  1. Control effects of steer-by-wire system for motorcycles on lane-keeping performance

    NASA Astrophysics Data System (ADS)

    Marumo, Yoshitaka; Katagiri, Nozomi

    2011-08-01

    This study discusses the control effects of the steer-by-wire (SBW) system for motorcycles on the lane-keeping performance by examining computer simulation with a rider-vehicle system which consists of a simplified vehicle model, a rider control model and the controller of the SBW system. The SBW system, which compensates the rolling angle deviation between the desired rolling angle intended by the rider and the actual rolling angle, improves the lane-keeping performance of the rider-vehicle system under the steering torque disturbance. The SBW system is, on the other hand, not effective in the lane-keeping performance under the lateral force disturbance. In addition, the lane-keeping assistance (LKA) system is applied to the SBW system and the cooperativeness of the SBW and the LKA systems is examined. The LKA system improves the lane-keeping performance of the SBW system under not only the steering torque disturbance but also the lateral force disturbance.

  2. LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

    SciTech Connect

    Gruchalla, Michael E.

    2011-01-01

    A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

  3. Description of the control system design for the SSF PMAD DC testbed

    NASA Technical Reports Server (NTRS)

    Baez, Anastacio N.; Kimnach, Greg L.

    1991-01-01

    The Power Management and Distribution (PMAD) DC Testbed Control System for Space Station Freedom was developed using a top down approach based on classical control system and conventional terrestrial power utilities design techniques. The design methodology includes the development of a testbed operating concept. This operating concept describes the operation of the testbed under all possible scenarios. A unique set of operating states was identified and a description of each state, along with state transitions, was generated. Each state is represented by a unique set of attributes and constraints, and its description reflects the degree of system security within which the power system is operating. Using the testbed operating states description, a functional design for the control system was developed. This functional design consists of a functional outline, a text description, and a logical flowchart for all the major control system functions. Described here are the control system design techniques, various control system functions, and the status of the design and implementation.

  4. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  5. An Overview of Power Electronics Applications in Fuel Cell Systems: DC and AC Converters

    PubMed Central

    Ali, M. S.; Kamarudin, S. K.; Masdar, M. S.; Mohamed, A.

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  6. DC graphite arc furnace, a simple system to reduce mixed waste volume

    SciTech Connect

    Wittle, J.K.; Hamilton, R.A.; Trescot, J.

    1995-12-31

    The volume of low-level radioactive waste can be reduced by the high temperature in a DC Graphite Arc Furnace. This volume reduction can take place with the additional benefit of having the solid residue being stabilized by the vitrified product produced in the process. A DC Graphite Arc Furnace is a simple system in which electricity is used to generate heat to vitrify the material and thermally decompose any organic matter in the waste stream. Examples of this type of waste are protective clothing, resins, and grit blast materials produced in the nuclear industry. The various Department of Energy (DOE) complexes produce similar low-level waste streams. Electro-Pyrolysis, Inc. and Svedala/Kennedy Van Saun are engineering and building small 50-kg batch and up to 3,000 kg/hr continuous feed DC furnaces for the remediation, pollution prevention, and decontamination and decommissioning segments of the treatment community. This process has been demonstrated under DOE sponsorship at several facilities and has been shown to produce stable waste forms from surrogate waste materials.

  7. Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.; Singer, S.

    1989-01-01

    A calculation of the starting torque ratio of permanent magnet, series, and shunt-excited dc motors powered by solar cell arrays is presented for two cases, i.e., with and without a maximum-power-point tracker (MPPT). Defining motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 for the permanent magnet motor and a magnification of 7 for both the series and shunt motors are obtained. The study also shows that all motor types are less sensitive to solar insolation variation in systems including MPPTs as compared to systems without MPPTs.

  8. Stability of large DC power systems using switching converters, with application to the international space station

    NASA Technical Reports Server (NTRS)

    Manners, B.; Gholdston, E. W.; Karimi, K.; Lee, F. C.; Rajagopalan, J.; Panov, Y.

    1996-01-01

    As space direct current (dc) power systems continue to grow in size, switching power converters are playing an ever larger role in power conditioning and control. When designing a large dc system using power converters of this type, special attention must be placed on the electrical stability of the system and of the individual loads on the system. In the design of the electric power system (EPS) of the International Space Station (ISS), the National Aeronautics and Space Administration (NASA) and its contractor team led by Boeing Defense & Space Group has placed a great deal of emphasis on designing for system and load stability. To achieve this goal, the team has expended considerable effort deriving a dear concept on defining system stability in both a general sense and specifically with respect to the space station. The ISS power system presents numerous challenges with respect to system stability, such as high power, complex sources and undefined loads. To complicate these issues, source and load components have been designed in parallel by three major subcontractors (Boeing, Rocketdyne, and McDonnell Douglas) with interfaces to both sources and loads being designed in different countries (Russia, Japan, Canada, Europe, etc.). These issues, coupled with the program goal of limiting costs, have proven a significant challenge to the program. As a result, the program has derived an impedance specification approach for system stability. This approach is based on the significant relationship between source and load impedances and the effect of this relationship on system stability. This approach is limited in its applicability by the theoretical and practical limits on component designs as presented by each system segment. As a result, the overall approach to system stability implemented by the ISS program consists of specific hardware requirements coupled with extensive system analysis and hardware testing. Following this approach, the ISS program plans to begin

  9. The Effects of Operational Parameters on a Mono-wire Cutting System: Efficiency in Marble Processing

    NASA Astrophysics Data System (ADS)

    Yilmazkaya, Emre; Ozcelik, Yilmaz

    2016-02-01

    Mono-wire block cutting machines that cut with a diamond wire can be used for squaring natural stone blocks and the slab-cutting process. The efficient use of these machines reduces operating costs by ensuring less diamond wire wear and longer wire life at high speeds. The high investment costs of these machines will lead to their efficient use and reduce production costs by increasing plant efficiency. Therefore, there is a need to investigate the cutting performance parameters of mono-wire cutting machines in terms of rock properties and operating parameters. This study aims to investigate the effects of the wire rotational speed (peripheral speed) and wire descending speed (cutting speed), which are the operating parameters of a mono-wire cutting machine, on unit wear and unit energy, which are the performance parameters in mono-wire cutting. By using the obtained results, cuttability charts for each natural stone were created on the basis of unit wear and unit energy values, cutting optimizations were performed, and the relationships between some physical and mechanical properties of rocks and the optimum cutting parameters obtained as a result of the optimization were investigated.

  10. Drive laser system for the DC-SRF photoinjector at Peking University

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Wen; Huang, Sen-Lin; Lin, Lin; Zhao, Gang; Quan, Sheng-Wen; Liu, Ke-Xin; Chen, Jia-Er

    2016-01-01

    Photoinjectors are widely used for linear accelerators as electron sources to generate high-brightness electron beams. The drive laser, which determines the timing structure and quality of the electron beam, is a crucial component of a photoinjector. A new drive laser system has been designed and constructed for the upgraded 3.5-cell DC-SRF photoinjector at Peking University. The drive laser system consists of a 1064 nm laser oscillator, a four-stage amplifier, second and fourth harmonic generators, an optical system to transfer the UV pulses to the photocathode, and a synchronization system. The drive laser system has been successfully applied during stable operation of the DC-SRF photoinjector and its performance meets requirements. A 266 nm laser with an average power close to 1 W can be delivered to illuminate the Cs2Te photocathode and the instability is less than 5% for long time operation. The design considerations for improving the UV laser quality, a detailed description of the laser system, and its performance are presented in this paper. Supported by National Basic Research Project (973) (2011CB808302, 2011CB808304)

  11. Final Results of the Protected Superficial Femoral Artery Trial Using the FilterWire EZ System

    SciTech Connect

    Mueller-Huelsbeck, Stefan; Paulsen, Friedrich; Heller, Martin; Jahnke, Thomas

    2010-12-15

    The purpose of this study was to evaluate the safety and efficacy of debris-capture for distal protection using the FilterWire EZ Embolic Protection System (Boston Scientific, Mountain View, CA) with the additional aim to further define the incidence of distal embolization during superficial femoral artery (SFA) interventions. A prospective, single-centre registry was designed to evaluate the performance of the FilterWire EZ in capturing debris during standard SFA percutaneous intervention. The PRO-RATA study included 30 patients suitable for PTA (Fontaine IIb to III or Rutherford I to II classification). The primary end points were occurrence of distal embolization or decreased runoff, improvement in ankle-brachial index ankle-brachial index (ABI) after the procedure, and number of filters containing emboli. Secondary end points included major adverse events (i.e., procedure- or device-related death and/or clinical target lesion revascularisation), device delivery, deployment success, and incidence of embolic recovery (patients with device success exhibiting embolic protection in the filter). Procedural success was determined as {<=}30% residual stenosis with no worsening of distal runoff as determined on angiography. A total of 29 patients (age 66.2 {+-} 12 years; total no. of limbs = 30; total no. of lesions = 30) suitable for PTA were enrolled in the study between February 2007 and March 2008. There were 26 patients with claudication (Fontaine IIB) and 3 patients with stage IV peripheral vascular disease. In one patient, lesions in both legs were treated. No procedural or device-related complications occured. The average degree of stenosis was 86 {+-} 7%. Stenosis length ranged from 8 to 88 mm. The average degree of residual stenosis was 10 {+-} 10%. ABI improved from 0.56 {+-} 0.16 to 0.92 {+-} 0.19 (P < 0.05). No restenosis or dissection was seen at 1-month ultrasound follow-up. Macroscopic debris was found in 27 of 30 filters of all distal protection devices

  12. Alpha-beta monitoring system based on pair of simultaneous Multi-Wire Proportional Counters

    NASA Astrophysics Data System (ADS)

    Wengrowicz, U.; Amidan, D.; Orion, I.

    2016-08-01

    A new approach for a simultaneous alpha-beta Multi-wire Proportional Counter (MWPC) is presented. The popular approach for alpha-beta monitoring systems consists of a large area MWPC using noble gas flow such as Argon Methane. This method of measurement is effective but requires large-scale and expensive maintenance due to the needs of gas flow control and periodic replacements. In this work, a pair of simultaneous MWPCs for alpha-beta measuring is presented. The developed detector consists of a sealed gas MWPC sensor for beta particles, behind a free air alpha sensor. This approach allows effective simultaneous detection and discrimination of both alpha and beta radiation without the maintenance cost noble gas flow required for unsealed detectors.

  13. Impact of stray charge on interconnect wire via probability model of double-dot system

    NASA Astrophysics Data System (ADS)

    Xiangye, Chen; Li, Cai; Qiang, Zeng; Xinqiao, Wang

    2016-02-01

    The behavior of quantum cellular automata (QCA) under the influence of a stray charge is quantified. A new time-independent switching paradigm, a probability model of the double-dot system, is developed. Superiority in releasing the calculation operation is presented by the probability model compared to previous stray charge analysis utilizing ICHA or full-basis calculation. Simulation results illustrate that there is a 186-nm-wide region surrounding a QCA wire where a stray charge will cause the target cell to switch unsuccessfully. The failure is exhibited by two new states' dominating the target cell. Therefore, a bistable saturation model is no longer applicable for stray charge analysis. Project supported by the National Natural Science Foundation of China (No. 61172043) and the Key Program of Shaanxi Provincial Natural Science for Basic Research (No. 2011JZ015).

  14. Reliability analysis of the F-8 digital fly-by-wire system

    NASA Technical Reports Server (NTRS)

    Brock, L. D.; Goodman, H. A.

    1981-01-01

    The F-8 Digital Fly-by-Wire (DFBW) flight test program intended to provide the technology for advanced control systems, giving aircraft enhanced performance and operational capability is addressed. A detailed analysis of the experimental system was performed to estimated the probabilities of two significant safety critical events: (1) loss of primary flight control function, causing reversion to the analog bypass system; and (2) loss of the aircraft due to failure of the electronic flight control system. The analysis covers appraisal of risks due to random equipment failure, generic faults in design of the system or its software, and induced failure due to external events. A unique diagrammatic technique was developed which details the combinatorial reliability equations for the entire system, promotes understanding of system failure characteristics, and identifies the most likely failure modes. The technique provides a systematic method of applying basic probability equations and is augmented by a computer program written in a modular fashion that duplicates the structure of these equations.

  15. Mathematical model for the dc-ac inverter for the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Berry, Frederick C.

    1987-01-01

    The reader is informed of what was done for the mathematical modeling of the dc-ac inverter for the Space Shuttle. The mathematical modeling of the dc-ac inverter is an essential element in the modeling of the electrical power distribution system of the Space Shuttle. The electrical power distribution system which is present on the Space Shuttle is made up to 3 strings each having a fuel cell which provides dc to those systems which require dc, and the inverters which convert the dc to ac for those elements which require ac. The inverters are units which are 2 wire structures for the main dc inputs and 2 wire structures for the ac output. When 3 are connected together a 4 wire wye connection results on the ac side. The method of modeling is performed by using a Least Squares curve fitting method. A computer program is presented for implementation of the model along with graphs and tables to demonstrate the accuracy of the model.

  16. Cost Effective Open Geometry HTS MRI System amended to BSCCO 2212 Wire for High Field Magnets

    SciTech Connect

    Kennth Marken

    2006-08-11

    the project start and that date a substantial shift in the MRI marketplace occurred, with rapid growth for systems at higher fields (1.5 T and above) and a consequent decline in the low field market (<1.0 T). While the project aim appeared technically attainable at that time, the conclusion was reached that the system and market economics do not warrant additional investment. The program was redirected to develop BSCCO 2212 multifilament wire development for high field superconducting magnets for NMR and other scientific research upon an agreement between DOE and Oxford Instruments, Superconducting Technology. The work t took place between September, 2004 and the project end in early 2006 was focused on 2212 multifilamentary wire. This report summarizes the technical achievements both in 2212 dip coated for an HTS MRI system and in BSCCO 2212 multifilamentary wire for high field magnets.

  17. The Influence of Pd-Doped Au Wire Bonding on HAZ Microstructure and Looping Profile in Micro-Electromechanical Systems (MEMS) Packaging

    NASA Astrophysics Data System (ADS)

    Ismail, Roslina; Omar, Ghazali; Jalar, Azman; Majlis, Burhanuddin Yeop

    2015-07-01

    Wire bonding processes has been widely adopted in micro-electromechanical systems (MEMS) packaging especially in biomedical devices for the integration of components. In the first process sequence in wire bonding, the zone along the wire near the melted tips is called the heat-affected zone (HAZ). The HAZ plays an important factor that influenced the looping profiles of wire bonding process. This paper investigates the effect of dopants on microstructures in the HAZ. One precent palladium (Pd) was added to the as-drawn 4N gold wire and annealed at 600°C. The addition of Pd was able to moderate the grain growth in the HAZ by retarding the heat propagation to the wire. In the formation of the looping profile, the first bending point of the looping is highly associated with the length of the HAZ. The alloyed gold wire (2N gold) has a sharp angle at a distance of about 30 m from the neck of the wire with a measured bending radius of about 40 mm and bending angle of about 40° clockwise from vertical axis, while the 4N gold wire bends at a longer distance. It also shows that the HAZ for 4N gold is longer than 2N gold wire.

  18. Load converter interactions with the secondary system in the Space Station Freedom power management and distribution DC test bed

    NASA Astrophysics Data System (ADS)

    Lebron, Ramon C.

    1992-08-01

    The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF Program design and development phases, a system Power Management and Distribution (PMAD) DC test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

  19. Load converter interactions with the secondary system in the Space Station Freedom power management and distribution DC test bed

    NASA Technical Reports Server (NTRS)

    Lebron, Ramon C.

    1992-01-01

    The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF Program design and development phases, a system Power Management and Distribution (PMAD) DC test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

  20. Load converter interactions with the secondary system in the Space Station Freedom power management and distribution dc test bed

    NASA Technical Reports Server (NTRS)

    Lebron, Ramon C.

    1992-01-01

    The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF program design and development phases, a system Power Management and Distribution (PMAD) dc test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

  1. Metallic Glass Wire Based Localization of Kinesin/Microtubule Bio-molecular Motility System

    NASA Astrophysics Data System (ADS)

    Kim, K.; Sikora, A.; Yaginuma, S.; Nakayama, K. S.; Nakazawa, H.; Umetsu, M.; Hwang, W.; Teizer, W.

    2014-03-01

    We report electrophoretic accumulation of microtubules along metallic glass (Pd42.5Cu30Ni7.5P20) wires free-standing in solution. Microtubules are dynamic cytoskeletal filaments. Kinesin is a cytoskeletal motor protein. Functions of these bio-molecules are central to various dynamic cellular processes. Functional artificial organization of bio-molecules is a prerequisite for transferring their native functions into device applications. Fluorescence microscopy at the individual-microtubule level reveals microtubules aligning along the wire axis during the electrophoretic migration. Casein-treated electrodes are effective for releasing trapped microtubules upon removal of the external field. Furthermore, we demonstrate gliding motion of microtubules on kinesin-treated metallic glass wires. The reversible manner in the local adsorption of microtubules, the flexibility of wire electrodes, and the compatibility between the wire electrode and the bio-molecules are beneficial for spatio-temporal manipulation of the motility machinery in 3 dimensions.

  2. A COAXIAL TE011 CAVITY AND A SYSTEM TO MEASURE DC AND RF PROPERTIES OF SUPERCONDUCTORS

    SciTech Connect

    Gianluigi Ciovati; Peter Kneisel; Ganapati Rao Myneni; Larry Turlington; Gary Slack; Michael Morrone; William Clemens; Richard Bundy; Thomas Elliott; Jayanta Mondal

    2008-01-23

    A coaxial niobium cavity has been designed and built where the center conductor consists of a removable sample. In addition, a system to measure properties such as magnetization, penetration depth, critical temperature and thermal conductivity on the same cylindrical sample has been designed and built. The purpose of this effort is to investigate possible correlations between DC and RF properties of superconductors. In this contribution, the design of the various components is discussed and the test results on a niobium sample obtained so far are presented.

  3. Earth to space dc to dc power transmission system utilizing a microwave beam as source of energy for electric propelled interorbital vehicles

    NASA Technical Reports Server (NTRS)

    Brown, W. C.

    1985-01-01

    The paper contributes to the credibility of an electric propelled interorbital transportation system by introducing a new low-mass source of continuous dc power for electric propulsion and illustrating how the source can be economically tied to an electric utility on earth by an electronically steered microwave beam. The new thin-film rectenna, which functions as the receiving end of an earth-to-space microwave power transmission system is described. It is easily fabricated, is over 80 percent efficient, has a specific mass of no more than 2 kilograms per kilowatt of continuous dc power output, and is well adapted for deployment in space. The paper then describes a complete system consisting of the interorbital vehicle and the microwave power transmission system that supplies it with power. A design scenario is used to obtain performance data from the system in terms of vehicle transfer times, payload fractions, and costs. Electric energy costs are found to be less than $1000 per kilogram of payload delivered to geosynchronous orbit from low-earth orbit.

  4. Water Desalination with Wires.

    PubMed

    Porada, S; Sales, B B; Hamelers, H V M; Biesheuvel, P M

    2012-06-21

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode pairs in freshwater with and in brine without an applied cell voltage, we create an ion adsorption/desorption cycle. We show experimentally how in six subsequent cycles we can reduce the salinity of 20 mM feed (brackish) water by a factor of 3, while application of a cation exchange membrane on the cathode wires makes the desalination factor increase to 4. Theoretical modeling rationalizes the experimental findings, and predicts that system performance can be significantly enhanced by material modifications. To treat large volumes of water, multiple stacks of wire pairs can be used simultaneously in a "merry-go-round" operational mode. PMID:26285717

  5. Study of a guarded electrode system in the dc conductivity measurement of insulating liquid

    NASA Astrophysics Data System (ADS)

    Zhou, Yuan; Hao, Miao; Chen, George; Wilson, Gordon; Jarman, Paul

    2014-07-01

    The design and choice of an electrode system is important in dc conductivity measurement of insulating liquid. In this paper, the electric field distribution of an electrode system which consists of two parallel circular metallic electrodes and a guard electrode has been studied using Comsol Multiphysics software. A new parameter, which is not yet involved in current standards, the edge radius, has been mentioned in the literature formerly and is currently discussed in a CIGRE working group. In this paper, the influence of this parameter has been investigated by means of field calculation. As seen from the simulating result, there are regions in the vicinity of the edges of the guard and measuring electrode that are under high electric field. If the edges of these two electrodes are sharp, the maximum electric field in the test cell will be much higher than the average field between the measuring electrode and the high voltage electrode. An empirical equation has been proposed to calculate this maximum field. The classic correction expression for an effective radius has been re-evaluated with the edge radius being taken into account. Experimental work has been performed to confirm this conclusion. Three kinds of mineral oils with different ageing times have been tested under the dc field using a guarded electrode system and the electric strengths of these oils have been estimated. A recommendation has been made to current standards in insulating liquid measurement.

  6. Photosynthesis and antioxidant defense system of Gynura Bicolor DC grown at different elevated CO2 levels

    NASA Astrophysics Data System (ADS)

    Wang, Minjuan; Liu, Hong; Fu, Yuming

    Atmospheric carbon dioxide concentration [CO _{2}] will increase in the future and will affect global climate and ecosystem productivity. However, this is not clearly an area that requires further study on the most appropriate [CO _{2}] selection for plant growth and quality in a closed, controlled environment. The aim of this study was to determine the variation of photosynthetic characteristics and antioxidant status under five CO _{2} concentration (400, 800, 1200, 2000 and 3000 umol mol (-1) ) on the leaf of Gynura bicolor DC. Here the results show that net photosynthetic rate(Pn), Chl content, edible biomass(EB), leaf blade width(LBW), root weight(RW), fructose(Fru) and sucrose(Suc) of Gynura bicolor DC increased under elevated [CO _{2}] of 800 umol mol (-1) , 1200 umol mol (-1) and 2000 umol mol (-1) . On the contrary, photosynthesis and biomass production declined significantly at 3000 umol mol (-1) CO _{2}, While Lipid peroxidation (LPO), malondialdehyde (MDA) and hydrogen peroxide (H _{2}O _{2}) achieved the highest levels. Furthermore, the contents of glutathione (GSH), vitamin C (VC), and vitamin E (VE), and total antioxidant capacity (T-AOC), the activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) reached the highest level at 2000 umol mol ({-1) }CO _{2}. Results imply that a significant increase in growth and antioxidant defense system of Gynura bicolor DC occurred under 800-2000 umol mol (-1) of CO _{2} concentration provided a theoretical basis for the application for plants selection in Bioregeneration Life Support System (BLSS) and a closed controlled environment.

  7. Solid State Remote Power Controllers for high voltage DC distribution systems

    NASA Technical Reports Server (NTRS)

    Billings, W. W.; Sundberg, G. R.

    1977-01-01

    Presently, hybrid Remote Power Controllers (RPC's) are in production and prototype units are available for systems utilizing 28VDC, 120VDC, 115VAC/400 Hz and 230VAC/400 Hz. This paper describes RPC development in a new area of application: HVDC distribution systems utilizing 270/300VDC. Two RPC current ratings, 1 amp and 2 amps, were selected for development as they are adequate to control 90% of projected system loads. The various aspects and trade-offs encountered in circuit development are discussed with special focus placed on the circuits that see the duress of the high dc potentials. The comprehensive evaluation tests are summarized which confirmed the RPC compliance with the specification and with system/load compatibility requirements. In addition, present technology status and new applications are summarized.

  8. Three dimensional finite element methods: Their role in the design of DC accelerator systems

    SciTech Connect

    Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W.

    2013-04-19

    High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 Multiplication-Sign 300 mm{sup 2}. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

  9. Three dimensional finite element methods: Their role in the design of DC accelerator systems

    NASA Astrophysics Data System (ADS)

    Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W.

    2013-04-01

    High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 × 300 mm2. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

  10. Investigations of some aspects of the spray process in a single wire arc plasma spray system using high speed camera.

    PubMed

    Tiwari, N; Sahasrabudhe, S N; Tak, A K; Barve, D N; Das, A K

    2012-02-01

    A high speed camera has been used to record and analyze the evolution as well as particle behavior in a single wire arc plasma spray torch. Commercially available systems (spray watch, DPV 2000, etc.) focus onto a small area in the spray jet. They are not designed for tracking a single particle from the torch to the substrate. Using high speed camera, individual particles were tracked and their velocities were measured at various distances from the spray torch. Particle velocity information at different distances from the nozzle of the torch is very important to decide correct substrate position for the good quality of coating. The analysis of the images has revealed the details of the process of arc attachment to wire, melting of the wire, and detachment of the molten mass from the tip. Images of the wire and the arc have been recorded for different wire feed rates, gas flow rates, and torch powers, to determine compatible wire feed rates. High speed imaging of particle trajectories has been used for particle velocity determination using time of flight method. It was observed that the ripple in the power supply of the torch leads to large variation of instantaneous power fed to the torch. This affects the velocity of the spray particles generated at different times within one cycle of the ripple. It is shown that the velocity of a spray particle depends on the instantaneous torch power at the time of its generation. This correlation was established by experimental evidence in this paper. Once the particles leave the plasma jet, their forward speeds were found to be more or less invariant beyond 40 mm up to 500 mm from the nozzle exit. PMID:22380128