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The N.Y. State Urban Development Corp., Amp Inc., and Western Electric Corp. are working with NASA to produce flat conductor electrical cable. Flat conductor electrical cable originally designed for spacecraft by the Marshall Space Flight Center, has been installed in a housing project. Because it is very thin the wire can be mounted on surfaces of walls and floors instead of inside of them. Installation costs reduced significantly due to single installation time.
A voltage feed-through apparatus, having reduced partial discharge, has an electrical conductor and an electrical terminal connected thereto. A semiconductor sleeve surrounds the conductor for reducing the electric field concentration at the metallic conductor surface and consequently reducing the partial discharge occurrences. An insulator sleeve encircles the semiconductor sleeve. A metallic sleeve surrounds a portion of the terminal. Another insulator is connected to the metallic sleeve and surrounds a portion of the insulator sleeve forming a space therebetween. Another metallic sleeve spaced from the first metallic sleeve surrounds a portion of the other insulator.
A test apparatus is described for locating electrical shorts that is especially suited for use while an electrical circuit is being fabricated or assembled. A ring counter derives input pulses from a square wave oscillator. The outputs of the counter are fed through transistors to an array of light emitting diodes. Each diode is connected to an electrical conductor, such as a bus bar, that is to be tested. In the absence of a short between the electrical conductors the diodes are sequentially illuminated. When a short occurs, a comparator/multivibrator circuit triggers an alarm and stops the oscillator and the sequential energization of the diodes. The two diodes that remain illuminated identify the electrical conductors that are shorted.
Aircraft are the last major mode of transportation to undergo electrification for many reasons, where the underlying reason is the sensitivity of aircraft performance to mass. This sensitivity demands that efficient, megawatt (MW)-scale high specific power density powertrains be developed to impact regional, single aisle and larger aircraft that account for the majority of fuel burn in commercial aviation. Developing MW-scale high specific power electric powertrains (machines, cables/busbars and power electronics) remains a significant challenge. While advanced power semiconductors have enabled higher voltages, densities, and operational frequencies this also leads to passing high current through smaller volumes when considering electric machines and power electronics. This poses significant thermal challenges. This is particularly true for electric machines that strive to surpass 13 kW/kg, which studies have shown to be desirable for electric aircraft propulsion. The necessity of handling high current densities to achieve MW power levels dictates that greater than 10kW of waste heat will be generated. Moreover, most of the heat is generated in the stator winding which is a mixture of electrical conductor (copper or aluminum), potting material, magnet wire (electrical) insulation and high voltage electrical insulation. Although the electrical conductor is a fantastic thermal conductor, it is also the source of the heat (carrying the electrical current) and is thermally isolated by the other materials. Simply letting the machine run at increased temperatures is an attractive idea, however the reality is that most of the suitable electric insulations and potting material candidates are not likely to satisfactorily operate at higher temperatures with reasonable life expectancies. The likelihood of developing new polymers that can satisfy the necessary functions (mechanical and electrical), operate at higher temperatures with acceptable lifetime in the near term is small. This has led the researchers at the NASA Glenn Research Center to examine electrically insulative materials in high power destiny electric machines, their thermal environment, and what solutions are realistic from a materials point of view. This presentation will touch on both the thermal challenges of electric machines and NASA Glenn’s research into material solutions.
Gravitationally induced electric field in conductor including effect of lattice compressibility
A level-sensing probe positioned in a tank is divided into sections with each section including (i) a fluid-level capacitive sensor disposed along the length thereof, (ii) an inductor electrically coupled to the capacitive sensor, (iii) a sensor antenna positioned for inductive coupling to the inductor, and (iv) an electrical conductor coupled to the sensor antenna. An electrically non-conductive housing accessible from a position outside of the tank houses antennas arrayed in a pattern. Each antenna is electrically coupled to the electrical conductor from a corresponding one of the sections. A magnetic field response recorder has a measurement head with transceiving antennas arrayed therein to correspond to the pattern of the housing's antennas. When a measurement is to be taken, the measurement head is mechanically coupled to the housing so that each housing antenna is substantially aligned with a specific one of the transceiving antennas.
A hermetically-sealed edge-connect header that can withstand high temperatures, high pressures (or high vacuum levels), and high vibration environments, along with two corresponding connectors are disclosed. After brazing the edge-connect header components, the assembly is machined to form a slot with a portion of each of a plurality of electrical conductors removed in the machining process, resulting in a header with a high pin density. During the process of mating the first connector design to the edge-connect header, a plurality of wipers in the connector deflect, thereby causing the wipers to extend from the connector and contact the corresponding electrical conductors in the header. During the process of mating the second connector design to the edge-connect header, each of a plurality of wipers formed of low-mass, compliant metal wool, forms multiple contact points with a corresponding electrical conductor in the header.
A hermetically-sealed edge-connect header that can withstand high temperatures, high pressures (or high vacuum levels), and high vibration environments, along with two corresponding connectors are disclosed. After brazing the edge-connect header components, the assembly is machined to form a slot with a portion of each of a plurality of electrical conductors removed in the machining process, resulting in a header with a high pin density. During the process of mating the first connector design to the edge-connect header, a plurality of wipers in the connector deflect, thereby causing the wipers to extend from the connector and contact the corresponding electrical conductors in the header. During the process of mating the second connector design to the edge-connect header, each of a plurality of wipers formed of low-mass, compliant metal wool, forms multiple contact points with a corresponding electrical conductor in the header.
A hermetically-sealed edge-connect header that can withstand high temperatures, high pressures (or high vacuum levels), and high vibration environments, along with two corresponding connectors are disclosed. After brazing the edge-connect header components, the assembly is machined to form a slot with a portion of each of a plurality of electrical conductors removed in the machining process, resulting in a header with a high pin density. During the process of mating the first connector design to the edge-connect header, a plurality of wipers in the connector deflect, thereby causing the wipers to extend from the connector and contact the corresponding electrical conductors in the header. During the process of mating the second connector design to the edge-connect header, each of a plurality of wipers formed of low-mass, compliant metal wool, forms multiple contact points with a corresponding electrical conductor in the header.
The upwind leapfrog or Linear Bicharacteristic Scheme (LBS) has previously been implemented and demonstrated on one-dimensional electromagnetic wave propagation problems. This memorandum extends the Linear Bicharacteristic Scheme for computational electromagnetics to model lossy dielectric and magnetic materials and perfect electrical conductors in two dimensions. This is accomplished by proper implementation of the LBS for homogeneous lossy dielectric and magnetic media and for perfect electrical conductors. Both the Transverse Electric and Transverse Magnetic polarizations are considered. Computational requirements and a Fourier analysis are also discussed. Heterogeneous media are modeled through implementation of surface boundary conditions and no special extrapolations or interpolations at dielectric material boundaries are required. Results are presented for two-dimensional model problems on uniform grids, and the Finite Difference Time Domain (FDTD) algorithm is chosen as a convenient reference algorithm for comparison. The results demonstrate that the two-dimensional explicit LBS is a dissipation-free, second-order accurate algorithm which uses a smaller stencil than the FDTD algorithm, yet it has less phase velocity error.
Flat conductor cable (FCC) is relatively new, highly promising means for electrical packaging and system integration. FCC offers numerous desirable traits (weight, volume and cost savings, flexibility, high reliability, predictable and repeatable electrical characteristics) which make it extremely attractive as a packaging medium. FCC, today, finds wide application in everything from integration of lunar equipment to the packaging of electronics in nuclear submarines. Described are cable construction and means of termination, applicable specifications and standards, and total FCC systems. A list of additional sources of data is also included for more intensive study.
Inkjet printing is a common commercial process. In addition to the familiar use in printing documents from computers, it is also used in some industrial applications. For example, wire manufacturers are required by law to print the wire type, gauge, and safety information on the exterior of each foot of manufactured wire, and this is typically done with inkjet or laser printers. The goal of this work was the creation of conductive inks that can be applied to a wire or flexible substrates via inkjet printing methods. The use of inkjet printing technology to print conductive inks has been in testing for several years. While researchers have been able to get the printing system to mechanically work, the application of conductive inks on substrates has not consistently produced adequate low resistances in the kilohm range. Conductive materials can be applied using a printer in single or multiple passes onto a substrate including textiles, polymer films, and paper. The conductive materials are composed of electrical conductors such as carbon nanotubes (including functionalized carbon nanotubes and metal-coated carbon nanotubes); graphene, a polycyclic aromatic hydrocarbon (e.g., pentacene and bisperipentacene); metal nanoparticles; inherently conductive polymers (ICP); and combinations thereof. Once the conductive materials are applied, the materials are dried and sintered to form adherent conductive materials on the substrate. For certain formulations, increased conductivity can be achieved by printing on substrates supported by low levels of magnetic field alignment. The adherent conductive materials can be used in applications such as damage detection, dust particle removal, smart coating systems, and flexible electronic circuitry. By applying alternating layers of different electrical conductors to form a layered composite material, a single homogeneous layer can be produced with improved electrical properties. It is believed that patterning alternate layers of different conductors may improve electrical pathways through alignment of the conductors and band gap optimization. One feature of this innovation is that flexible conductive traces could be accomplished with a conductive ink having a surface resistivity of less than 10 ohms/square. Another result was that a composite material comprising a mixture of carbon nanotubes and metallic nanoparticles could be applied by inkjet printing to flexible substrates, and the resulting applied material was one to two orders of magnitude more conductive than a material made by printing inks containing carbon nanotubes alone.
A system for monitoring electrostatic charge buildup and electrostatic discharge (ESD) remotely comprises a plurality of electrostatic charge measurement units and a data acquisition device. Each electrostatic charge measurement unit includes a primary charge plate, a static sensor device, a secondary charge plate, and a shielded cable. The primary charge plate is positioned proximal to an object. The static sensor device includes an input sensor at which an electric voltage is measured and outputs an electronic signal whose level varies according to the measured electric voltage. The secondary charge plate is positioned in proximity to the input sensor of the static sensor device. The shielded cable includes an inner conductor electrically connected to the primary charge plate and the secondary charge plate and an outer conductor electrically connected to electrical ground. The data acquisition device receives the electronic signal from the static sensor device of each electrostatic charge measurement unit.
The upwind leapfrog or Linear Bicharacteristic Scheme (LBS) has previously been implemented and demonstrated on electromagnetic wave propagation problems. This paper extends the Linear Bicharacteristic Scheme for computational electromagnetics to model lossy dielectric and magnetic materials and perfect electrical conductors. This is accomplished by proper implementation of the LBS for homogeneous lossy dielectric and magnetic media and for perfect electrical conductors. Heterogeneous media are modeled through implementation of surface boundary conditions and no special extrapolations or interpolations at dielectric material boundaries are required. Results are presented for one-dimensional model problems on both uniform and nonuniform grids, and the FDTD algorithm is chosen as a convenient reference algorithm for comparison. The results demonstrate that the explicit LBS is a dissipation-free, second-order accurate algorithm which uses a smaller stencil than the FDTD algorithm, yet it has approximately one-third the phase velocity error. The LBS is also more accurate on nonuniform grids.
Passive and active methods for anticipating problems with electrical wiring are provided. An insulative material in contact with an electrical conductor has at least one impurity that is impregnated in the insulative material and/or disposed thereon. An environment around the electrical conductor is monitored for the presence or the level of the impurity(ies) emanating from the insulative material in the form of a gaseous effluent. An alarm signal is generated when a predetermined level of the gaseous effluent is detected.
The upwind leapfrog or Linear Bicharacteristic Scheme (LBS) has previously been implemented and demonstrated on electromagnetic wave propagation problems. This paper extends the Linear Bicharacteristic Scheme for computational electromagnetics to treat lossy dielectric and magnetic materials and perfect electrical conductors. This is accomplished by proper implementation of the LBS for homogeneous lossy dielectric and magnetic media, and treatment of perfect electrical conductors (PECs) are shown to follow directly in the limit of high conductivity. Heterogeneous media are treated through implementation of surface boundary conditions and no special extrapolations or interpolations at dielectric material boundaries are required. Results are presented for one-dimensional model problems on both uniform and nonuniform grids, and the FDTD algorithm is chosen as a convenient reference algorithm for comparison. The results demonstrate that the explicit LBS is a dissipation-free, second-order accurate algorithm which uses a smaller stencil than the FDTD algorithm, yet it has approximately one-third the phase velocity error. The LBS is also more accurate on nonuniform grids.
A semiconductor power device including a base plate; an input lead; an output lead; a field effect transistor (FET) power die disposed over the base plate, wherein the FET power die includes a set of source fingers, a set of drain fingers, and a set of gate fingers disposed directly over an active region, wherein the gate fingers are configured to receive an input signal from the input lead, and wherein the FET power die is configured to process the input signal to generate an output signal at the drain fingers for routing to the output lead; and electrical conductors (wirebonds or ribbons) bonded to the source and/or drain directly over the active region of the FET power die. The electrical conductors produce additional thermal paths between the active region and the base plate for thermal management of the FET power die.
A wireless temperature sensor includes an electrical conductor and a material spaced apart from the conductor and located within one or more of the responding electric field and responding magnetic field of the conductor. The conductor is electrically unconnected and is shaped for storage of an electric field and a magnetic field. In the presence of a time-varying magnetic field, the conductor resonates to generate harmonic electric and magnetic field responses, each of which has a frequency associated therewith. The material is selected such that it experiences changes in one of dielectric properties and magnetic permeability properties in the presence of a temperature change. Shifts from the sensor's baseline frequency response indicate that the material has experienced a temperature change.