Showing papers on "Insulator (electricity) published in 1978"

Method for forming an insulator between layers of conductive material

Abstract: A method for forming an insulator between conductive layers, such as highly doped polycrystalline silicon, that involves first forming a conductive layer of, for example, polycrystalline silicon on a silicon body having substantially horizontal and substantially vertical surfaces. A conformal insulator layer is formed on the substantially horizontal and substantially horizontal and vertical surfaces. Reactive ion etching removes the insulator from the horizontal layer and provides a narrow dimensioned insulator on the vertical surfaces silicon body. Another conductive layer, which may be polycrystalline silicon, is formed over the insulator. The vertical layer dimension is adjusted depending upon the original thickness of the conformal insulator layer applied.

Studies on electrical conductivity of insulator‐conductor composites

Abstract: The variation of electrical resistivity of an insulator‐conductor composite, namely, wax‐graphite composite, with parameters such as volume fraction, grain size, and temperature has been studied. A model is proposed to explain the observed variations, which assumes that the texture of the composite consists of insulator granules coated with conducting particles. The resistivity of these materials is controlled mainly by the contact resistance between the conducting particles and the number of contacts each particle has with its neighbors. The variation of resistivity with temperature has also been explained with the help of this model and it is attributed to the change in contact area.

Factors Controlling Surface Flashover in SF6 Gas Insulated Systems

Abstract: Various factors controlling the flashover of solid insulators in pressurized SF6, are reviewed and their influences in gas insulated systems are discussed from a practical point of view. Flashover voltage of clean insulator surface is under the influence of the insulator-metal contact as well as the macroscopic electric field distortion due to the high dielectric permittivity of solid insulator. Conducting particles or even fine metal powder can reduce the flashover voltage. Their effects are strongly dependent on the position they are located, the size of the insulator and gas pressure. Humidity of SF, gas should be strictly governed in SF, gas insulated apparatuses, since the condensation of water can decrease flashover voltage considerably. Decomposition products of SF6 due to the arcing in switchgears are deleterious to epoxy insulators particularly when silica is used as their filler. The decomposition products decrease the leakage resistance on the insulation surface. The field strength near positive electrode is enhanced by the electrolytic effect in the surface conduction layer. In some extreme condition, it initiates tracking on the insulator surface.

Insulating spacer for double insulated glass

Abstract: An improved insulating spacer to reduce the heat transfer between the two panes of glass of double insulated glass comprises an extruded or roll-formed metal spacer together with a plastic insulating element which thermally isolates the metal spacer from the panes of glass while permitting conventional application of the sealant to provide reliable bonding. In one embodiment the plastic insulator comprises an extruded plastic overlay which fits tightly over part of a conventional metal spacer and has projecting contacts which abut the glass.

Electrical properties of the gallium arsenide–insulator interface

Abstract: Extensive capacitance–voltage (C–V) measurements have been performed on three types of insulators on n‐type GaAs: pyrolytically deposited silicon nitride, sputtered silicon nitride, and the oxide produced by anodization. Evaporated aluminum gate contacts and alloyed Au–Ge ohmic contacts were applied and the C–V characteristics of these structures were measured from the quasistatic regime to 150 MHz. Although differences in detail are seen at intermediate frequencies, the data taken at the extreme frequency limits differ very little for the three types of specimens. The quasistatic and high‐frequency data are consistent with a model wherein the surface potential with zero applied gate bias is ∠−0.8 V. Application of electric fields of the order of ±106 V/cm at the semiconductor surface results in movement of the surface potential across approximately 1/3 of the band gap. An accumulation layer of surface electrons could not be produced on any of the devices tested.

Method and apparatus for generating charged particles

Abstract: Generation of charged partides, e.g. ions, by extracting them from a high density source provided by an electrical gas breakdown in an electric field between two conducting electrodes separated by an insulator. When a high frequency electric field is applied, surprisingly high ion current densities can be obtained, providing numerous advantages over conventional ion forming techniques for use in electrostatic printing and office copying.

The Nature and Practice of Gases as Electrical Insulators

Abstract: The gaseous state of matter is an excellent high voltage insulator which nonetheless is subject to overstresses and electrical breakdown. The main parameters which govern insulation strength in gases are identified as gas density and time duration of applied voltage. Several gases show similar effects of density and time changes so that generalized breakdown curves are presented. Practical considerations for the design of high voltage equipment are also developed through examples of insulation performance in compressed SF6. Features emphasized include the influence of electrode surfaces, particle contamination and solid insulating supports. Significant achievements in the application of gases to high voltage equipment and expected areas for future fundamental and applied developments are discussed.

The effect of Mn/Ti surface treatment on voltage‐holdoff performance of alumina insulators in vaccum

Abstract: The treatment of the surface of an alumina insulator with a Mn/Ti coating significantly increases its voltage‐holdoff capability. Insulators treated with this coating had vacuum‐holdoff voltages about 25% higher than did untreated insulators. During processing (quasimetallizing) the coating penetrates into the alumina, so it is fairly insensitive to damage by abrasion or electrical breakdown. The quasimetallized coatings is also comparable with subsequent metallizing and brazing of the alumina insulator. We conclude that the coating (1) decreases the surface resistivity of the insulator, (2) decreases the insulator’s secondary‐electron‐emission yield, and (3) makes the surface of the insulator dielectrically more uniform.

Static charge accumulated by epoxy post insulation stressed at high DC voltages

Abstract: Solid insulators are used for support in many types of high voltage apparatus. Because these supports are often composed of high resistivity materials, static charges may be accumulated and held by them for extended periods of time. The electric field distribution in the vicinity of the insulator is then altered so that electrical breakdown in the surrounding gas may result.

Investigation of high voltage spacecraft system interactions with plasma environments

Abstract: The exposure of high voltage spacecraft systems to the charged particle environment of space can produce interactions that will influence system operation. An experimental investigation of these interactions has been undertaken for insulator and conductor test surfaces biased up to plus or minus 1 kV in a simulated low earth orbit charged particle environment. It has been found that these interactions are controlled by the insulator surfaces surrounding the biased conductors. For positive applied voltages the electron current collection can be enhanced by the insulators. For negative applied voltages the insulator surface confines the voltage to the conductor region; this can cause arcing. Understanding these interactions and the technology to control their impact on system operation is essential to the design of solar cell arrays for ion drive propulsion applications that use direct drive power processing.

Mass terminable shielded flat flexible cable and method of making such cables

Abstract: A shielded cable comprises a flat electrical insulator having a plurality of parallel spaced-apart conductors. A plurality of openings extend through the insulator to expose at least one conductor. The shield, which is formed from an electrically conductive coating, not only covers the exterior of the insulator but also enters the openings and is electrically connected to the conductor. Gaps are created in the electrically conductive coating so as to provide areas for interconnection by an insulation displacement connector which "mass-terminates" all of the connectors. The exposed one conductor, which is in contact through the openings with the electrically conductive coating, maintains the electrical continuity of the shield notwithstanding the gap formed therein.

Adaptor for paper-insulated, lead-jacketed electrical cables

Abstract: An adaptor for placement at the terminus of an electrical power distribution cable having diametral dimensions falling within a given range of sizes, the cable being of the oil-filled type including a conductor, a paper insulator and a lead jacket, to seal the terminus and enable installation, in the field, of an electrical connector for use in an electrical power distribution system. The adaptor includes a sleeve portion of insulating material for placement over the cable insulation, a conductor-sealing portion for receiving the conductor of the cable, a jacket-sealing portion for juxtaposition with the lead jacket to seal the juncture between the lead jacket and the adaptor, a dielectric filler for placement between the cable insulation and the sleeve portion, and an electrical stress control member for controlling electrical stress along the interface between the cable insulation and the dielectric filler.

The characterisation of metal-thin insulator-n-p+ silicon switching devices

Abstract: 2014 Experiments are reported on the switching characteristics of MISS devices incorporating a thin ( 50 Å) oxide layer, including the influence of a modulating base current, the effect of temperature and the dynamic performance. A quantitative analysis of a regenerative model of switching is briefly described and shown to give a good account of the experimental results. REVUE DE PHYSIQUE APPLIQUÉE TOME 13, DÉCEMBRE 1978,

Method of making an ignition plug insulator having an electrically conductive end

Abstract: An ignition plug insulator provided at its front end with a closed ignition portion. The closed front end of the ignition portion is impregnated with an electric conductivity imparting material to form a ceramic electrode. Alternatively, the ceramic electrode may be incorporated in the closed front end of the ignition portion or filled in an axial bore provided in the insulation.

Electronic States near Metal-Insulator Interface

Abstract: Electronic states near the interface of metal-insulator are investigated laying stress on many-body effects with the aid of the Hubbard model. It can be shown that insulator-metal transition may occur at insulator surface under the condition when the energy gap of the insulator caused by many-body effects is small and transfer matrix elements between the two substances are suitably chosen.

Insulator Edge Voltage Gradient Effects in Spacecraft Charging Phenomena

Abstract: Insulating surfaces on geosynchronous satellites have been charged by geomagnetic substorms to a point where discharges occur. The electromagnetic pulses from these discharges couple into satellite electronic systems disrupting operations. Laboratory tests conducted on insulator charging have indicated that discharges appear to be initiated at insulator edges where voltage gradients can exist. An experimental investigation has been conducted to measure edge voltage gradients on silvered Teflon samples as they are charged by monoenergetic electron beams. It has been found that the surface voltage at insulator edges can be approximated by an exponential expression based on an electron current density balance. Using this expression at known breakdown conditions results in a discharge voltage gradient down the insulator edge to ground of about 1.5×105 V/cm. Seams between insulation strips and imperfections in insulation can intensify voltage gradients and contribute to discharges. It appears that such discharges can occur on satellite surfaces in space.

High impact - arc track and weather resistant polymer insulator and composition including epoxidized castor oil

Abstract: An arc track resistant, high voltage, filled synthetic resin insulator is disclosed which exhibits a wide range of desirable qualities heretofore unobtainable with any single type of prior insulator. The insulator hereof unexpectedly gives excellent arc track and flame resistance, along with a flexibilized yet rugged construction having good weatherability properties. These qualities are achieved through use of a relatively critical selection of components and proportions which also facilitate cast construction of the insulators by giving a pourable, yet highly filled liquid casting composition during the fabrication stage. The insulators include critical quantities of hydrated alumina (from about 60 to 75% by weight) and a synthetic resin matrix having expoxidized castor oil (18 to 24% by weight) and a glycidyl rigidizer therein, along with a curing agent and accelerator.

Cable splicing technique

Abstract: An electrical cable splicing technique in which each joined conductor is insulated with a self-fusing insulator pad of rubber which preferably is fabric reinforced, the insulated conductors then being wrapped with uncured vulcanizable rubber tape to build up the splice to dimensions of a jacket sleeve. The sleeve, which is of molded fabric reinforced rubber, is then installed and bonded to the splice area.

Effect of Large Electrodes on Sparkover Characteristics of Air Gaps and Station Insulators

Abstract: The paper constitutes a laboratory investigation into the influence of large electrodes on the dry and wet sparkover characteristics of air gaps and high voltage insulator supports. Tests were carried out with power frequency and switching impulse voltages.

Glass pass through with an additional insulator for lengthening leakage path

Abstract: Pass through having a glass part disposed in an opening formed in a metal case part, an insulator for lengthening the leakage path connected at an end face thereof to at least one end face of the glass part and at least one electric conductor extending through the glass part and the insulator, the connection between the insulator and the glass part including a fused glass junction.

Unsteady silicon nitride conductivity in high electric fields

Abstract: Unsteady currents are experimentally investigated in silicon nitride. The experiments made to separate the direct current from the capturing current show that the unsteady current at t > 3 s is a direct current. The carrier injection from the silicon—insulator is found to be affected by a tunnelling mechanism. Separation of the electron and hole components of the unsteady current shows that the current flowing near the silicon—insulator interface in a tunnelling thin oxide structure is transported by the carriers injected from silicon to the insulator. The current of the charges from the insulator to silicon is rather low. The high electric fields possess some unsteadiness displaying the current rise with time. The current rise is accompanied by appropriate field increase at the silicon—insulator interface resulting in the breakdown of the MNOS-structure. [Russian Text Ignored].

Influence of an insulating layer on the efficiency of a semiconductor-insulator-semiductor (SIS) heterojunction solar cell

Abstract: By theoretical analysis it is shown that inserting a thin insulating layer between the two semiconductors of a p + n solar cell, can improve the efficiency in the same way as for an MIS solar cell, if the discontinuity in the conduction bands constitutes a barrier for photon excited electrons. In the other cases, the insulating layer either plays no role or is disadvantageous.

Method of and apparatus for manufacturing insulator forcoaxial cable

Abstract: PURPOSE:To permit ready and simple formation of an insulator for coaxial cables, which has a uniform outer diameter in the direction of the length and a smooth outer surface

Assembly apparatus for electrical connectors

Abstract: A machine to assemble electrical contact retention clips automatically in an insulator including a slotted tube expandable by a tapered plunger to embed an electrical connector retention clip in a heated and softened insulator after having been inserted into an insulator bore by a ferrule slidable on the tube.

Cable for use of control with resistance against

Abstract: PURPOSE:To reduce drop of insulation resistance of a cable by employing as cable insulator polyethylene resin or styrene interpolymer which have such a propery that generation of especially long-life charge bearers caused by radiation of radial rays is small or they don't remain so much

Connector for coaxial and screened cables - has set of electrodes in trapped insulator accepting pairs of cable inner conductors esp. for aircraft electrical systems

Abstract: The connector is for coaxial or screened cables esp. for use in aircraft electrical systems. The connector allows cables to be permanently interconnected and to be coupled into other cables. It has an overall cylindrical form expanding into a short shoulder section. The coaxial or normally twisted pair cables (1, 2) screen conductors are teased away from the inner conductors (3, 3) in the shoulder section and twisted together to ensure common grounding. Single male or female electrodes (11) set in a trapped insulator can accept pairs of cables inner conductors.

Manufacture of heat exchanger

Abstract: PURPOSE: To obtain solid heat exchanger thru a process wherein adhesive agent consisting of hot melt material is painted in a plurality of stripe pattern and in embossed relief form on heat exchanging plates and are made as heat contacting zones. CONSTITUTION: Pipe body 2 has flattened surface on its side contacting the heat exchanging part 1, and is adhered on the plate 1 in the following procedures: (a) On the heat exchanging plate 1, adhesive agent containing hot melt material is painted in a plurality of stripe pattern and in embossed form protruding a little from the surface of plate 1, and is made as heat contacting zone; (b) Pipe body 2 is disposed upon with its longitudinal 2A striding across the plurality of painted stripes 4, and using jigs 5, 6 and the like, pipe body 2 is pressed closely against the heat contacting zones. By heating heat exchanger in this condition, adhesive agent at the pressed portion melts and pipe body 2 is completely contacted against the plate 1. Thru the above procedures, pipes are secured on the heat exchange plate, and when this method is applied at refrigerator, direct contact between heat insulator and heat exchange plate is made feasible, and a solid heat exchanger is rendered available. COPYRIGHT: (C)1980,JPO&Japio