Abstract: This is a device for electromagnetic transient protection for integrated circuit boards in a convenient and easily customized package. The device comprises an array of transient protection devices (TPDs) made in the form of sleeves on hollow pins and installed in a fiberglass board. The board has a copper coating to conduct transients away from the pin of the IC. The array of TPDs on the fiberglass board corresponds to the leg spacing of the IC being protected. The device is soldered onto the circuit board and the IC is in turn plugged into it possibly using a friction fit or else it is soldered. An unwanted transient signal enters the device and the IC simultaneously from the circuit board land. The device sees the transient and changes from a high impedance "off" state to its low impedance"on" state and conducts the transient away from the IC. The other pins remain off unless transients are also present at these pins. The TPDs may comprise metal oxide varistors in tubular form, zener diodes or surgectors.

Abstract: Surge-protective apparatus having a plurality of varistors or equivalent non-linear resistance means interconnected in parallel with one another between external power lines and ground to protect utility meters and downstream electrical equipment subject to damage from transient electrical surges. Interconnection is accomplished by interleaving electrically conductive laminar members in one or more assemblies of adjacent varistors, as in a cuplike holder.

Abstract: A distribution class surge arrester comprises a core formed of distributed zinc oxide varistor blocks, aluminum blocks acting as heat sinks and as spacers providing voltage grading and required arcing distances, and terminal blocks held in face-to-face contact by means of a glass reinforced epoxy shell which is formed by winding a pre-preg onto the assembled blocks and thermally curing under mold pressure within an evacuated mold. The core is housed within a polymeric shedded housing which is formed by shrinking a heat-shrink shedded sleeve onto the core with a sealant provided in the interface of the core and the sleeve, and end caps are sealed to the ends of the structure thus formed.

Abstract: An electrical overstress composite of conductor/semiconductor particles including particles in the 100 micron range, micron range, and submicron range, distributed in a densely packed homogeneous manner, a minimum proportion of 100 angstrom range insulative particles separating the conductor/semiconductor particles, and a minimum proportion of insulative binder matrix sufficient to combine said particles into a stable coherent body.

Abstract: A distribution class surge arrester having a core formed of distributed zinc oxide varistor blocks, aluminum blocks acting as heat sinks and as spacers providing voltage grading and required arcing distances, and terminal blocks held in face-to-face contact by means of a glass reinforced epoxy shell which is formed by winding a pre-preg onto the assembled blocks and thermally curing under mold pressure within an evacuated mold. The core is housed within a polymeric shedded housing which is formed by shrinking a heat-shrink shedded sleeve onto the core with a sealant provided in the interface of the core and the sleeve, and end caps are sealed to the ends of the structure thus formed.

Abstract: Disclosed is a station or distribution surge arrester of the type comprising a single column of varistors stacked one upon the other and centrally arranged in a cylindrical chamber provided in a casing made of an insulating material. A plurality of movable props, made of a material which is both insulating and non-elastic, are used for holding the varistors in column form centrally in the chamber, even if the varistors break diametrically as is often the case during a severe thermal shock. By holding the varistors permanently at the center of the chamber, the props ensure the non-obstruction of several vertical passages around the column, which passages allow an arc created within the surge arrester to move freely toward a pressure limiting diaphragm during failure of the latter and, thereby, reduce explosion risks to a minimum.

Abstract: A gapped low voltage bushing (10) comprising a controlled spark gap (1), a metallic arc strap (18), a resistive material (46) and a metallic tank ground pad. Surges entering the transformer on any of the secondary bushings of sufficient magnitude to induce gap sparkover, result in a shunting of otherwise damaging currents safely outside the transformer.

Abstract: An arrester for an under oil transformer is connected between a primary bushing lead and an insulator/isolator penetrating the wall of a housing which encloses the oil, arrester, and transformer parts. A ground wire outside the housing is removably connected to the isolator which functions as a circuit disconnector. The ground wire is removed to open circuit the arrester so that the transformer may be tested without having to disable any parts in the housing. Responsive to an arrester failure, the ground wire is blown away to give a visual indication of the failure. The blowing away of the ground wire eliminates the need for the arrester to fail in an open circuit condition.

Abstract: The insulative support bracket of a surge arrester includes a concentric annular concavity formed at one or both ends of a bolt hole. A washer, when pressed concentrically to the concavity, contacts the insulative bracket only, at least initially, at surfaces adjacent the outer diameter of the washer. An annular convexity, surrounding the concavity, will mate with the central portion of an external tooth lockwasher to prevent the full penetration of the teeth of the lockwasher into the insulative bracket. The ability of the insulative bracket to withstand the mechanical forces tansmitted to the insulative bracket by the washers is thereby enhanced. The concavity may be formed either in a surface of the insulative bracket or in a surface of the washer.

Abstract: A line protector for a communications circuit provides at least overvoltage protection. The overvoltage protection is effected through a solid state arrester such as a diode. As the solid state arrester is not as long as the carbon electrode type or gas tube arrester which it replaces, the line protector includes a conductive pedestal. The end of the pedestal adjacent to the solid state arrester is shaped to receive one electrode of the arrester, while the other end of the pedestal is shaped to provide a good contact to the grounding circuit of the protector.

Abstract: A surge suppression module for providing existing wiring devices with a surge suppressing element for protection against transient surges of voltage in a power circuit. The surge module includes a universal support member that accommodates variously voltage-rated surge suppressing elements and various covers that accommodate different female wiring devicese to be mounted therein. The surge module also includes an alarm for detecting an electrical malfunction in the surge suppressing element and an indicator light for indicating proper electrical functioning of the surge suppressing element.

Abstract: A protective circuit utilizing a variable impedance. In one aspect, where a spark gap is utilized, a low impedance capacitor connected to the electrodes forming the gap by low impedance leads operates to terminate an arc passing across the gap when the voltage is reduced below a predetermined breakdown voltage. In another aspect, a varistor is utilized. A pair of input and output terminals is spaced a selected distance apart to improve performance at high frequencies. A permanent short is created if the varistor is destroyed by a high-energy transient.

Abstract: An adapter to be plugged in between a conventional watt-hour meter and an electrical power use installation socket to protect both the meter and downstream equipment from possible damage by transient surges in electrical potential resulting from lightning or similar disturbance. For the usual meter having a pair of power input terminals and a pair of power output terminals, this adapter has a pair of varistors or similar non-linear resistances connected between the respective input terminals and ground, so as to conduct away such surges. It also preferably has a heat sink connected to the grounded side of the varistors to dissipate the thermal energy resulting from the surge conduction. Additional features include an indicator of operating condition and fuse links to the varistors.

Abstract: A fail-safe, non-fragmenting surge arrester includes a liner having outlets formed in the walls thereof for venting ionized gases generated within the liner by internal arcing. The vented ionized gas forms a lower impedance path for the current which is thereby shunted around the failed internal components, preventing the generation of internal pressure which could otherwise cause a fragmenting failure mode of the arrester. The internal components include stacked varistor elements and may include an internal fuse link electrically in series with the varistors.

Abstract: A lightning protector assembly for telephone circuitry and the like includes a housing formed of a lower necked terminal section and an upper expanded grounding section. A component-mounting member is disposed within the housing for mounting a first pair of voltage limiting devices and a first pair of impedance devices. There are cavities provided in the lower part of the component-mounting member for receipt of a plurality of terminal contacts. The upper section has a pair of top recesses separated by a central bridging portion. Plug-in fuse holder units are disposed within the top recesses. A side ground contact is provided and includes an elongated horizontal member extending inside and across the width of the housing for connection to the first pair of voltage limiting means and a portion thereof extending externally of the housing.

Abstract: A triggered surge suppression network is disclosed comprising a low voltage clamping device, a crowbar device and a trigger device. The voltage clamping device and the trigger device are connected in parallel; and these devices are connected in series to the crowbar device. The resulting circuit is connected across a voltage supply, in parallel to a load. The trigger device causes the crowbar device to break down at a pre-set value and discharge the energy of the surge through the low voltage clamping device. The breakdown voltage of the network will depend essentially on the breakdown voltage of the crowbar device while the peak voltage supplied to the load during the surge will independently be determined by the clamping voltage of the voltage clamping device.

Abstract: A lightning arrester having an insulating cylinder which contains resistance elements made of zinc oxide which have a nonlinear voltage-current characteristic are stored. The insulating cylinder is fixed at least one sealing member having passages which connect the inside space of the insulating cylinder with the outside space thereof. These passages are covered with a material adapted to be softened or melted by a heat and are therefore closed in an air-tight manner. The arrester also includes an arc guide for producing arc type spark short-circuit externally of the insulating cylinder due to gas jetted from the passages upon an arc accident in the insulatng cylinder.

Abstract: A surge arrester of modular form, including a metal oxide varistor disk having a coaxial shunt gap located within the disk. The metal oxide varistor disk has a hole located essentially through the center of the disk and includes top and bottom electrode plates having centrally located projections which protrude inwardly of the disk into the hole of the disk, thereby forming a shunt gap within the disk. The module may be used unhoused in under-oil applications or as a component part of a housed arrester. For under-oil applications, the electrode plates are solder sealed to the disk providing a seal preventing oil or moisture from entering the hole in the shunt gap. As an alternate embodiment the surge arrester module may include a series of two or more of such disks stacked between the top and bottom electrode plates.

Abstract: Electrical transient surge protection of electrical equipment downstream from a power source plus safeguarding of apparatus for providing such surge protection against failure at high currents or high temperature. Current-limiting and temperature-limiting fusible devices are used in conjunction with voltage-limiting devices, such as varistors, so as to protect watt-hour meters and downstream loads from electrical surges, and to safeguard such varistors from failure. Such apparatus may be located in such diverse places as a power line weatherhead, a watt-hour meter base, an adapter between a meter base and its normal mounting socket, or a circuit-breaker panel downstream of the meter and upstream of electrical loads metered thereby. The varistors are stacked in parallel circuit assemblies for heavy duty. Visible indicators of failure of the surge-protection are provided.

Abstract: An inexpensive, compact, portable, visual indicator electrical plug-type surge protector which comprises an electrical plug body composed of a molded transparent polymer, the plug body having an extended male grounding prong and a pair of male electrical prongs on one face and a female receiving grounding inlet and a pair of female receiving inlets on the opposite face. The plug body contains in a visually indicating position, generally slightly below the surface of the plug body, a metal oxide varistor electrically connected to the electrical outlet plug so as to prevent electrical surges from passing through the surge protector from the electrical source into which the electrical plug-type surge protector is plugged and to be activated and to change color on the occurrence of an electrical surge so that the user of the surge protector will know when the electrical surge has been received and thereby be able to replace the surge protector with a new surge protector.

Abstract: A modular electrical assembly is enclosed in an elastomeric weathershed housing, and has a plurality of electrical components aligned in a row with terminals at the row ends. The electrical components and the terminals are in electrical connection with one another via their axially-directed ends and are axially compressed by a non-conductive filament winding. The filament winding has axial end portions wrapped about the terminals and extending axially beyond the terminals in a direction opposite to the electrical components. The winding end portions are prestressed in axial compression to increase cantilever strength and to decrease cantilever deflection.

Abstract: An adapter to be plugged in between a conventional watt-hour meter and an electrical power use installation socket to protect both the meter and downstream equipment from possible damage by transient surges in electrical potential resulting from lightning or similar disturbance. For the usual meter having a pair of power input terminals and a pair of power output terminals, this adapter has varistors or similar non-linear resistances connected between the input terminals and ground, to conduct away such surges. Preferably a plurality of such resistances are connected, in parallel, between each input terminal and ground, and a heat sink is connected to the grounded side of the varistors to dissipate the thermal energy resulting from the surge conduction.

Abstract: An electrical device includes a plurality of electrical assemblies formed as interchangeable modules, aligned in an end-to-end serial array and enclosed in a polymeric weathershed housing, the electrical assemblies being electrically and mechanically coupled together. Each electrical assembly in turn has a plurality of electrical components aligned in a row and in electrical connection with one another via their axially-directed ends and under an axially-directed compressive force via a non-conductive filament winding. A plastic film barrier laterally surrounding the electrical components is interposed between the electrical components and the filament winding. A surge arrester with voltage ratings can be enlarged merely by serially coupling a plurality of separately wrapped electrical components in the form of MOV blocks. Enclosing the electrical assemblies is a weathershed housing.

Abstract: A circuit protection device for protecting an electrical circuit from a voltage transient, e.g. a voltage transient caused by an electrostatic discharge, lightning or a nuclear electromagnetic pulse, comprises a threshold switching element formed from an amorphous composition comprising germanium, selenium and optionally antimony, and a pair of electrodes in contact with the composition. The devices generally exhibit a good balance of physical properties including switching speed, energy required to latch them in their low resistance state, high resistance state (off) resistance, threshold voltage and capacitance, which enables them to be used successfully to protect electrical circuits from such transients.

Abstract: The protection arrangement according to the invention for protecting electric installations against lightning effects is characterized in that an electric relationship between a multiphase input line and the installation includes for each of the phases at least a first set of spark-gap arresters, at least a first self-inductance coil and at least a first variable resistance lightning arrester. Such an arrangement is particularly applicable to the protection of transformation units, hertzian relays or other delicate electric or electronic installations.

Abstract: A line protector for a communications circuit. The line protector has an overvoltage arrestor such as a three electrode gas tube, two of whose electrodes are connected to the line input terminals of the protector by associated conductive elements projecting from the protector base. The third electrode is connected to the ground terminal. The line protector also has two positive temperature coefficient resistors (PTCRs) which protect against marginal overcurrents. Conductive elements connected to the line protector's equipment terminals also project from the base in the same direction as the line input terminal conductive elements project. Each PTCR is in contact with an associated one of the two line input terminal conductive elements and an associated one of the two equipment terminal conductive elements.

Abstract: An electrical receptacle having front and rear casings forming an enclosed housing for a printed circuit board carrying contacts into which the blades of a plug connected to the receptacle are inserted. The housing includes portions cooperatively placed with respect to the circuit board to provide underlying support for the contacts, as well as to assist in positioning the circuit board relative to the housing. The circuit components carried by the circuit board include three varistor devices for suppressing high transient voltages and the housing includes internal walls providing spaced cavities to receive the respective varistor devices. Another aspect concerns a one-piece mounting strap positioned entirely exteriorly of the receptacle housing and connected thereto by cooperative engagement portions on the strap and the housing, requiring no screws, rivets or other fastening devices.

Abstract: A lightning arrester includes a stack of zinc oxide pellets (1) seated in counterbored recesses of intermediate tubular spacers (2) and two metal end fittings (3). This assembly is wrapped in a filament winding (4) at an angle of 80-90 degrees with the stack axis, thereby providing radial binding without significant axial compression. The filament winding adheres to the side surfaces of all the components of the stack.

Abstract: A trigger circuit for a spark gap chain with at least two series-connected spark gaps, of which at least one is provided with at least one trigger electrode, includes a resistor chain which is connected in parallel with the spark gap chain and comprises at least two series-connected resistor groups. That of the resistor groups which is connected in parallel with the spark gap provided with a trigger electrode comprises a voltage-dependent resistor, built up of zinc oxide varistors, which is connected in series with a linear resistor. The voltage across the linear resistor is supplied to the trigger electrode of the spark gap for ignition of the spark gap when this voltage amounts to a pre-determined value. The spark gaps are primarily intended to be utilized for overvoltage protection of series capacitors.

Abstract: A distribution class surge arrester comprises a core formed of distributed zinc oxide varistor blocks, aluminum blocks acting as heat sinks and as spacers providing voltage grading and required arcing distances, and terminal blocks held in face-to-face contact by means of a glass reinforced epoxy shell which is formed by winding a pre-preg onto the assembled blocks and thermally curing under mold pressure within an evacuated mold. The core is housed within a polymeric shedded housing which is formed by shrinking a heat-shrink shedded sleeve onto the core with a sealant provided in the interface of the core and the sleeve, and end caps are sealed to the ends of the structure thus formed.

Abstract: When the lightning device is overheated because of its long-time discharge, a conductive member having a low melting point is softened and melted by the overheated tube to short-circuit an air gap between main discharge electrodes. The main discharge electrodes are thus short-circuited to protect the lightning arrester from being overheated and damaged. When discharge function is lost between the main discharge electrodes, air discharge is carried out in the air gap. Electric appliances and machine connected to the lightning arrester can be thus protected from high voltage surge.

Abstract: An enclosure for electric device, in particular for surge arrester, comprises an outer, cylindrical envelope and an inner wall both made of electrically non conducting materials. One of the ends of the envelope is closed while the other is open. An electrode with a principal portion inside the enclosure extends through the envelope and projects outside the latter. Bolt anchors are used for fixing the enclosure on a mechanical support and for mounting a closure device on the open end of the envelope. The material constituting the inner wall is impervious to humidity and protects the envelope against breaking thereof by thermal shock caused for example by the production of an electric arc within the enclosure, while the material constituting the cylindrical envelope is a synthetic insulating material capable of withstanding a high mechanical tension.

Abstract: The present invention relates to a method of manufacturing a lightning arrester (100) having two end fittings (2,20) at either end of a substantially cylindrical central core constituted by a stack of pellets (6, 7, 8) made of a varistor-type material and having holes therethrough whereby the pellets are threaded over a central rod (1) made of stratified material. The stack assembly is put into compression against the two facing faces of the end fittings (2, 20) by means of the rod (1), the space between the rod (1) and the pellets (6, 7, 8) is filled by casting or injecting an insulating material, with the assembly obtained in this way being perfectly rigid, and a coating (30) of an elastomer of the EPDM type is molded over the assembly, with the coating adherring perfectly to all of the surfaces of the core and of the end fittings which it covers.

Abstract: A lightning arrester with a monolithic, active resistor core made of voltage-dependent resistance material based on ZnO is produced by mixing and grinding the base materials ZnO+metal oxides, producing pourable granules, filling into a silicone rubber tube and pressing cold-isostatically or radially into a moulding, sintering of the moulding into a self-supporting, monnolithic resistor core, converting the resistor core, with an insulator by casting around, coating or painting with an epoxy resin, silicone material or concrete polymer or by drawing over a shrink-fit tube or by glazing. The resultant lightning arrester has a simple configuration, good reproducibility, cost-effective mass production.

Abstract: A grounding tank type arrester comprises a plurality of columns sorted into current folding columns and current pass columns. Each current folding column includes a plurality of stack sets of an element unit, having a plurality of zinc oxide elements, and an insulating spacer and the plural stack sets are stacked in regular sequence so that one element unit and one insulating spacer are stacked alternately. Each current pass column includes a plurality of stack sets of a zinc oxide element and an insulating spacer and the plural stack sets are stacked in regular sequence so that one zinc oxide element and one insulating spacer are stacked alternately. Individual zinc oxide elements on one level of individual current folding columns and individual zinc oxide elements on the one level of individual current pass columns are interconnected together by bridge conductor plates.

Abstract: A surge arrestor comprises at least one surge arresting element mounted between a pair of electrodes. The assembly is secured together longitudinally by a plurality of heat recoverable polymeric strands, and is contained within a heat recoverable shedded polymeric housing of electrically insulating and non-tracking material.

Abstract: This surge arrester is for protecting against high-energy and very fast surges and comprises first and second electrodes and a metal oxide varistor (MOV) disk between the electrodes. Each electrode has a central region and, at generally diametrically-opposed sides thereof, a source terminal and a load terminal. The terminals of each electrode are connected in the protected circuit in such a manner that load current in each of the conductors of the protected circuit flows through the electrode via a path that extends in series through the source terminal, the central region, and the load terminal. The source terminals of the two electrodes are generally aligned with each other about the periphery of the MOV disk, and the load terminals are also generally aligned with each other about the periphery of the disk.

Abstract: An underoil surge arrester (10) having metal oxide varistor disks (12) held in place by flexible spring clips (18).

Abstract: In a lightning arrestor insulator wherein a ZnO element having voltage non-linear resistant characteristics is embedded in an insulator body and integrally fixed with a glassy bonding material, the glassy bonding material has a thermal expansion coefficient smaller than either of those of the ZnO element and the insulator body. As the glassy bonding material, a low melting PbO-B.sub.2 O.sub.3 system glass having a composition to separate, during solidification, low expanding ceramic crystals is preferably employed.

Abstract: A device for suppressing transient surges in electrical power available from an electrical outlet is disclosed. The device is adapted for mounting on a back side portion of the electrical outlet. Surge protection components, such as planar varistors are disposed within an insulative housing block which forms the body of the device, and the device is physically mounted and electrically connected to the electrical outlet by mounting apparatus such as stiff metal leads.

Abstract: In order visually to indicate the existence of a "continuation" current through a lightning arrester, an indicator is associated therewith, which is formed by an elastically deformable strip maintained retracted against capsule electrode by a retention mechanism which is associated with an electrical filter which causes fusion of a fusible wire under the effect of a "continuation" current. Once its end is released, the strip projects outwardly of the lightning arrester and marks the location of the defective insulation.

Abstract: A lightning arrester for discharging electricity from an electrode in a container of the ground voltage level filled with electric insulation fluid when an excessive voltage is imposed on the electrode. The arrester has characteristic elements for selectively discharging electricity and an insulation tube for enclosing the characteristic elements. The insulation tube is so arranged as that part of the characteristic elements are inserted in the container and some of them project out. The characteristic elements are connected to the electrode in the container, and selectively connected and disconnected to the ground.

Abstract: An arrester for use under oil in an electrical apparatus, the arrester comprising a first contact assembly, a plurality of valve blocks, a second contact assembly, and a conductive cement serially electrically connecting the first contact assembly, each of the plurality of valve blocks, and the second contact assembly. The arrester also includes a thin insulative inert to oil coating completely covering the plurality of valve blocks, the coating and the cement permitting electrical separation of the valve blocks in the event of electrical destruction of the valve blocks.

Abstract: A high-voltage apparatus having a casing (1) filled with an insulating medium, an active part (6) connected to high voltage in the casing, and a pressure-relief valve (2) closing off the casing (1). The pressure-relief valve (2) includes a hinged cover (9) and a bending spring (12) acting on the cover (9). The pressure-relief valve (2) responds extremely quickly to changes in pressure of the insulating medium located in the casing (1). This is achieved partially by the fact that the bending spring (12) lies in the current path of the active part (6) connected to the high voltage and due to the fact that the bending spring (12) is formed with weakened regions which are heated faster by the current. As a result, the rigidity of this bending spring (12) suddenly drops as the current exceeds a predetermined value. This results in sudden relieving of the pressure in casing (1).

Abstract: A lightning-conducting insulator is disclosed, which comprises an insulator body consisting of a shed portion, a plurality of rib portions provided inside the shed portion, and a cup-like cylindrical head portion at a central upper portion of the shed portion, and a metal cap put and fixed onto the head portion, and a metal pin inserted and fixed inside the head portion. A cylindrical fitting section with a through hole is provided in the shed portion. At least one current-limiting element having a non-linear voltage-current characteristic is inserted into the through hole of the cylindrical fitting section. The cylindrical fitting section is sealed with a glass- and ceramics-bonding metal solder such that the upper and lower end faces of the current-limiting element and the end faces of the cylindrical fitting section may be continuously sealed.

Abstract: A voltage surge suppression circuit employs two series connected metal oxide varistors and a power interrupter to provide suppression of all modes of voltage surge while providing protection against failure of either metal oxide varistor. An indicator is provided to indicate the status of the circuit to the user.

Abstract: A lightning arrester with a monolithic, active resistor core made of voltage-dependent resistance material based on ZnO is produced by mixing and grinding the base materials ZnO+metal oxides, producing pourable granules, filling into a silicone rubber tube and pressing cold-isostatically or radially into a moulding, sintering of the moulding into a self-supporting, monolithic resistor core, converting the resistor core, with an insulator by casting around, coating or painting with an epoxy resin, silicone material or concrete polymer or by drawing over a shrink-fit tube or by glazing. The resultant lightning arrester has a simple configuration, good reproducibility, cost-effective mass production.

Abstract: A material provides protection against electrical overstress transients having rise times as rapid as a few nanoseconds or less. The material comprises a matrix formed of a mixture of separate particles of conductive materials and separate particles of semiconductor materials coated with insulating material to provide chains of the particles within the matrix with interparticle separation distances along the chains less than several hundred angstroms, thereby to permit quantum-mechanical tunneling of electrons between the separate particles in response to high energy electrical transients.

Abstract: A current limiting horn device for a transmission line supported by sets of insulators suspended from arms of steel towers. The device includes horns located respectively at charging and earthing portions of each set of the insulators and spaced horizontally apart a predetermined distance from a vertical axis of the set of the insulators. At least one of the horns is provided with an arrester element of a resistance having a non-linearity. According to the invention, a ratio Z/Zo of a distance Z between the horns to a total length Zo of the one set of insulators is not more than 0.5, thereby when extraordinary voltage caused by lightening surge is applied to the transmission line, securely causing flash-over between horns to prevent any earthing accident which would otherwise occur in the transmission line.