Abstract: Electrostatic discharge (ESD) protection circuits include first and second pads on an integrated circuit and first and second well regions in the integrated circuit substrate. The first and second well regions include respective first and second circumferences or walls. First and second diodes are included in the respective first and second well regions. The first and second diodes are serially connected between the first and second pads. A first guard ring is included adjacent the first circumference, and preferably in the first well. The first diode is included within the first guard ring. A second guard ring is also preferably included adjacent the second circumference, and most preferably in the second well. The second diode is included within the second guard ring.

Abstract: A surge protector module is provided with a housing with an internal space, a separator disposed within the housing which divides the internal space into first and second spaces within the housing, and a surge protection device. The surge protection device has a surge protector mounted within the first space and a disconnect mechanism operable to conductively disconnect one of the terminals of the surge protector from one of the terminals of the surge protection device in the presence of a prolonged overvoltage surge across the terminals of the surge protector. A combustion-retardant material is disposed within the housing of the surge protector module so that it occupies only the first space within the housing, leaving the second space within the housing substantially free of the combustion-retardant material, and the disconnect mechanism is disposed in the second space in which no combustion-retardant material is disposed.

Abstract: A Schmitt trigger-configured overvoltage protection circuit has a hysteresis turn-on, turn-off characteristic that minimizes its sensitivity to noise, and is effective to protect an integrated circuit against a DC overvoltage condition, and electrostatic discharge-based transients, while allowing `hot` insertion of a device containing the clamping circuit into an already powered-up system. The protection circuit employs a reference device, such as a Zener diode, that enables the clamping circuit trigger threshold to be set at a value that is independent of the power supply voltage.

Abstract: An ESD protection circuit includes a pair of NPN lateral transistors electrically connected in series with the emitter of one of the transistors electrically connected to the collector of the other transistor. The bases of the two transistors are electrically connected together and are floating. The two transistors may be provided by two MOS transistors having N-type source and drains and P-type channel regions. The channels regions are connected together and are floating.

Abstract: A hybrid surge protector architecture is configured to accommodate a plurality of replaceable L-shaped communication signal surge protection modules and a multi receptacle AC voltage terminal strip in the same housing architecture. The modules may be configured to provide surge protection for different types of communications signal lines. The hybrid surge protector has a housing structure which contains a floor, a vertical wall and convex cover. A first portion of the wall has an opening in which an AC voltage terminal strip is installed. A second portion of the wall has an aperture for a plurality of communication signal surge protection circuit modules. Hot and neutral leads of the terminal strip are coupled to input ports of the AC voltage surge protection circuit. A reference ground conductor for the terminal strip and the AC voltage surge protection circuit is mounted along the housing floor adjacent to the terminal strip.

Abstract: A tank-type surge arrester includes a zinc oxide element unit having zinc oxide elements, a top shield ring for earth insulation control disposed on top of the zinc oxide element unit, an upper shield ring disposed below the top shield ring in an upper section of the zinc oxide element unit, an expanded lower shield ring disposed below the upper shield ring in the upper section of the zinc oxide element unit, and tubular conductors disposed between the upper and the lower shield rings so as to be included in a vertical plane on an extension of a high-tension conductor.

Abstract: A lighting arrester in the form of a double-ended polymer enclosure contains one or more varistor discs in vertical alignment having terminals at the opposing ends for external electrical connection. The discs are formed from a zinc oxide composition with metal electrodes on opposing faces that are electrically connected with each other and with the end terminals by U-shaped metal straps.

Abstract: An electrostatic discharge protection circuit comprises an NMOS transistor and a silicon-controlled rectifier. The NMOS transistor is configured with one source/drain region connected to a first node, and its gate as well as another source/drain region connected to a second node. The silicon-controlled rectifier comprises a PNP transistor, an NPN transistor, and a resistor. The PNP transistor is provided with a first emitter connected to the first node, a first base disconnected from the first node, and a first collector. The NPN transistor is provided with a second emitter connected to the second node, a second base connected to the first collector and a second collector connected to the first base. However, the resistor is connected between the second base and the second node. The NMOS transistor enters breakdown to trigger the silicon-controlled rectifier to conduct a discharge current when electrostatic discharge stress occurs between the first node and the second node.

Abstract: The overvoltage suppressor contains two connecting fittings (1, 2), which are spaced apart from one another along an axis (z) and between which at least one cylindrical varistor element (8) is arranged. The connecting fittings (1, 2) and the at least one varistor element (8) are braced with respect to one another, forming a contact force, to form a mechanically robust active part of the overvoltage suppressor. The active part is sheathed by a molded housing made of insulating material. In each case one material cutout is formed in each of the two connecting fittings (1, 2) with a section (15, 16) which runs essentially transversely with respect to the axis (z), is designed in the form of a slot and extends from the outer surface of the fitting (1, 2) to beyond the axis (z).

Abstract: A surge protection circuit provides multiple stages of protection for an electronic circuit having semiconductor components from damage due to passage of excessive amount of current during a line borne voltage surge. In particular, this circuit can protect any relay load switching device that requires an electronic control circuit. The circuit of the invention achieves performance superior to that of conventional surge protectors, such as those employing metal oxide varistors, by employing an expulsion arrester as the last stage of a multi-stage protection technique against voltage surges on power lines. Low impedance electrical paths parallel to the expulsion arrester and to the electronic circuitry provide protection before the arrester switches. One embodiment employs a zener diode and a silicon controlled rectifier to provide two such parallel electrical paths.

Abstract: An improved apparatus and method for encapsulating a single large MOV is shown. The MOV is sandwiched between aluminum contact plates. An epoxy fills the void space between the contact plates. A dielectric film encapsulates the entire sandwich. Soft films of aluminum foil or a deposition coating is used to cover the MOV surface to cure facial defects. An optional exterior case protects the MOV assemblies contained therein from short circuits due to dirt, grease or water build-up. The apparatus is designed to withstand over 100,000 amps of surge in a commercial up to 220 volt per phase secondary power system.

Abstract: Protection of a cable, its termination and other apparatus from lightning strikes on an overhead line is provided by housing a surge arrestor and a cable termination, which are connected in parallel in a common housing, but as separate components not sharing the same axial line. With this configuration, minimal lead length is provided without sacrificing serviceability.

Abstract: The surge arrester has an axially symmetrical active portion (2) arranged between two connection fittings (1, 2). This active portion (2) contains varistor elements (12) stacked one above the other and also an axially symmetrical connecting element (13) of electrically conductive material arranged in the active portion (2) of the arrester between two successive varistor elements (12). At least four mounting places (16, 16'), which are uniformly distributed around the axis in the circumferential direction, are formed in the connecting element (13). Two first (16) of the mounting places support respectively one of two first loops (15) which act with contact force on the connecting element (13) and on the varistor elements (12) abutting the connecting element (13). Two second (16') of the mounting places support respectively one of two second loops (15) which act with contact force on the connecting element (13) and on the varistor elements (12) located under the connecting element.

Abstract: A solvent-free liquid conductive material designed to protect electrical components, such as printed circuit boards from high pulse static electricity. The solvent-free liquid conductive material comprises a liquid silicone polymer, powdered metallic compound, non-conductive inorganic powder and a curing agent. The conductive material is applicable to both additively and subtractively processed printed circuit boards.

Abstract: A surge arrester includes an electrically insulating arrester housing and a surge arresting block housed within the electrically insulating arrester housing. The surge arresting block is arranged to provide support for the surge arrester without the use of a support member. The surge arresting block may be a single surge arresting block having a voltage rating of at least 9 KV. The surge arresting block may have threads formed integrally therewith.

Abstract: An over voltage cut-off circuit of a private branch exchange for cutting off the over voltage induced into an E&M (ear and mouth) tie line, includes an E ("ear") line over voltage cut-off circuit composed of an E arrestor which generates heat by the over voltage induced through the E port, and also of an E fuse which melts and blows if it surpasses a melting point. The circuit may also include an M ("mouth") line over voltage cut-off circuit.

Abstract: A modular electrical assembly is enclosed in an elastomeric weathershed housing, and has a plurality of electrical components and end terminals aligned in a column 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. The filament winding defines a crisscross pattern with lateral openings for venting gas upon failure of one of the electrical components. The openings can be filled with fracturable epoxy or other insulating materials. Each end terminal has an electrically conductive part with a radially extending flange at its inner end, and an electrically insulative part mounted over the electrically conductive part and engaging the flange.

Abstract: A transient voltage surge suppressor (TVSS) receptacle includes front and rear matable casings including a plurality of through openings for receiving the blades of an electrical plug; an electrical circuit within the receptacle having at least one element adapted to clamp high transient voltages imposed thereon to a lower level; an alarm electrically connected to the at least one element for indicating the failure of the at least one element; and a reversible push-button on-off switch assembly for repeatedly engaging or disengaging the alarm.

Abstract: A suppressing capacity circuit for use with a transient voltage protection device; the transient voltage protection device includes a plurality of series-coupled current-limiting elements and transient-suppressing elements couplable between first and second electrical conductors to suppress transient voltages therebetween, the current-limiting elements being adapted to open-circuit upon the failure of a transient-suppressing element coupled in series therewith.

Abstract: Cable interconnection apparatus for connecting coaxial cable and fiber optic cable, the cable interconnection apparatus being adapted to be removably mounted in network interface devices containing subscriber bridge modules.

Abstract: The present invention relates to a passive electronic component architecture employed in conjunction with various dielectric and combinations of dielectric materials to provide a differential and common mode filter for the suppression of electromagnetic emissions and surge protection. The architecture allows single or multiple components to be assembled within a single package such as an integrated circuit or connector. The component's architecture is dielectric independent and provides for integration of various electrical characteristics within a single component to perform the functions of filtering, fusing and surge suppression, alone or in combination.

Abstract: The overvoltage suppressor has a cylindrical active part, which is arranged between two electrically conductive, cylindrical fittings and contains at least one varistor on a metal-oxide base, as well as an insulating material housing which surrounds the active part and is closed at the ends by the fittings. The insulating material housing is filled with an insulating material which surrounds the active part on the outside and is formed by an injection-molded or extruded insulating material tube and by a shielded weather protection which is held on the outer surface of the tube. A first of the two fittings is integrally formed into the tube at a first of its two ends. An external thread on the second fitting is screwed into an internal thread in the tube, forming a contact force.

Abstract: A surge protector is provided that has a gas tube and at least one MOV that is coordinated with the gas tube such that the MOV interacts with the gas tube to lower the impulse breakdown voltage of a gas tube of a type that has a wide range of DC breakdown voltages across a population of the gas tubes. The gas tube is a generally cylindrical three element gas tube and the MOVs are disposed at opposite ends of the gas with fusible elements maintained in position by a clip. A population of the gas tubes has a range of breakdown voltages and the clamping voltage of the MOVs is set within this range such that the MOV will interact with any gas tube with a breakdown voltage in the population range to divert a surge to ground.

Abstract: A circuit for limiting voltage transient excursions on a power supply node is disclosed. The circuit includes a first field effect transistor dispose to provide a capacitance and having source and drain electrodes coupled to said external supply node path and having a gate electrode and first and second clamp transistors. A resistance is coupled between the gate electrode of said first transistor and the internal supply return node and to gate electrodes of the clamp transistors. The circuit also include process resistances between internal and external supply connection to provide a charge transfer path between external and internal supply nodes and external and internal return nodes.

Abstract: The lightning arrestor has two metal end fittings for connection purposes, a stack of electrically conductive components extending along a longitudinal axis between the two end fittings, and an envelope surrounding the electrical components and the end fittings in such a manner as to maintain electrical contact between the components. The envelope is made of a thermoplastic material that molded over the electrical components and the end fittings. It has an embossed outside surface including depressions and projections. The depressions correspond to zones of reduced envelope wall thickness and they serve to constitute lateral openings through the envelope for allowing gas to escape to the atmosphere.

Abstract: A surge suppressor disconnect protection circuit is coupled to a first surge suppressor. The first surge suppressor is electrically coupled to phase and neutral line terminals of an AC source to protect the first surge suppressor from predetermined overvoltages. The circuit includes a relay switch with a relay contact and a relay drive coil. The relay contact is setable to one of a high and a low impedance state. The relay contact is electrically connected to the first surge suppressor and to one of the line terminals. A signal adjuster is electrically connected at its phase port to the AC phase terminal and to the AC neutral terminal for rectifying AC to generate a DC signal. The adjuster filters the DC signal and scales the filtered DC signal. An amplifier is electrically coupled to the adjuster at a non-inverting input port and to a first voltage reference at an inverting input port. The amplifier output port is electrically coupled back to the inverting input port to provide a feedback path therebetween.

Abstract: A lightning arrester device with a housing (7) having two electrical contact terminals and consisting of at least one housing element (7a, 7b) containing at least one protective element (13) with terminals electrically connected to the contact terminals, the protective element being embedded in an insulating material (17) contained in the housing element (7). At least one sturdy sleeve (19) is inserted between the housing element (7) and the protective element (13) in the insulating material (17). The housing element (7a, 7b) constitutes one of the contact terminals.

Abstract: A surge arrester (1) includes varistor elements (2) forming a stack (3) and having opposed end surfaces (4a, 4b). The varistor stack is electrically connected via the opposed end surfaces to end terminals (7a, 7b) having circumferential ridges (32a, 32b), which, in the event of failure of the varistor elements, are designed to relocate the resulting arc and direct it in a manner which reduces or minimizes damage to the surge arrester. The ridges serve as damage-tolerant sacrificial rooting points for an arc in the event of varistor element failure by presenting a substantial metal mass for the arc to erode away.

Abstract: The invention is a MOV based surge arrester that uses MOVs manufactured from a recently patented process. These new technology MOVs are significantly more uniform in their composition, resulting in more uniform performance. Each MOV is packaged by placing it between a pair of contact plates, preferably manufactured from aluminum. This packaging significantly increases the surface area between the contact plates and the MOVs. Wiring is minimized. Also, the use of the metal plates increases the ability of a surge suppresser to remove the heat generated in severe over-voltage situations. The preferred embodiment teaches conductor wires soldered to a disk in a grid pattern. The grid pattern provides a low empedance connection and prevents failure of the MOV at a lower than expected voltage. Grid patterns can include spiral, serpentine S, and square patterns.

Abstract: A surge protection circuit including a first MOSFET and a second MOSFET connected in series. The drain of the first MOSFET is connected to the input terminal and the source of the second MOSFET is grounded. The gate of the second MOSFET is grounded, whereas the gate of the first MOSFET is connected to a high potential power supply terminal. This makes it possible to equalize the voltages applied to the two MOSFETs constituting the surge protection circuit, and weakens the intensity of the internal electric field of respective MOSFETs, thereby prolonging the lifetime of the surge protection circuit. The surge protection circuit is particularly effective in a SOI LSI.

Abstract: An electrical overstress composite of conductor/semicondcutor 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 surge arrester has end terminals having circumferential ridges, which, in the event of failure of varistor elements of the surge arrester, are designed to relocate the resulting arc and direct it in a manner which reduces or minimizes damage to the surge arrester. Grooves lead from the inner surface of the terminals to the ridges, to facilitate arc relocation.

Abstract: An arrester assembly which retains all the components thereof in an assembled condition is disclosed. The arrester assembly can be handled as an individual subassembly for use in a line protector. The arrester assembly includes a cup which has a base, at least one wall, and an open end. A sleeve is retained within the cup by an interference fit between the outside of the sleeve and the inside surface of the cup. An arrester element having a first face and a second face is retained within the sleeve with the first face in conductive contact with the base of the cup. A solder contact in the form of an elongated beam is positioned within the sleeve in abutting contact with the second face of the arrester element. The beam includes engaging structures which are forced past an inner ridge on an internal surface of the sleeve for retaining the beam in position in the sleeve.

Abstract: An electrical overstress (EOS) protection circuit for protecting an active circuit of an integrated circuit including first and second clamping circuits series connected between a first input and a first input/output of the EOS protection circuit and third and fourth clamping circuits connected between a first output of the protection circuit and a second input/output. In embodiments of the present invention an EOS protection circuit provides protection for an active circuit while enabling a voltage at an input pad to the active circuit to exceed a power supply reference by more than several volts and to be less than a ground reference by more than several volts.

Abstract: A surge absorber comprises a housing, electrode bars, leads and an air chamber. A core constituted by layers of conductive and non-conductive material is provided between the electrode bars. The air chamber is filled with inert gases. The materials of the conductive and non-conductive layers can be arbitrarily laminated to form an integrated body, and the shape of the core may be multiple stepped tower-like. The working voltage is 80 V-3668 volts, and the discharging light emitting time is less than 10.sup.-6 sec.

Abstract: An input protection circuit protects semiconductor circuits from ESD voltages and excessive voltages. The protection circuit includes an input/output node, a resistor (or other resistive element), and a varistor. The resistor has a first end coupled to the input/output node and a second end coupled to a port of the protected circuit. The varistor has a first end coupled to a ground node and a second end coupled to the second end of the resistor. The electronic circuit is coupled to the second end of the resistor and the second end of the varistor.

Abstract: A composite article is formed from yarn, comprising high strength fibres and fusible blocking material, and outer fusible material. The yarn is formed into its required shape and placed in a mould. The outer fusible material is introduced into the mould and its temperature is raised so as to melt the lower-melt temperature blocking fibres of the yarn. Under the action of temperature and pressure in the mould, the blocking material fuses so as to fill any interstices between the strength fibres, and the yarn is enclosed within the outer fusible material. The method is useful for forming electrical insulators of high strength glass fibre in the form of a loop (4) blocked against flow of moisture by polypropylene and enclosed within non-tracking polyethylene electrically insulating material (6).

Abstract: A varistor-based voltage suppression circuit is coupled to a power distribution system having at least one power line and at least one neutral line. A varistor is coupled directly to the power and neutral lines of the distribution circuit so that the electric current travels across at least one planar surface of the varistor, thus eliminating one or more leads from the distribution circuit to the varistor circuit. The suppression circuit may be a single varistor or a number of varistors in parallel with a number of lines in the distribution circuit.

Abstract: A surge arrester designed for use with lines of 2 kV or less has a housing (10) which, in combination with a cup-shaped gasket (25), an O-ring gasket (45) and a lid (20), seals a varistor element (30) inside against environmental contaminants such as water or pollutants.

Abstract: An improved power filter circuit is disclosed. The improvement concern providing a clamping device between a ground lead and a terminal of a safety circuit such that when the power filter has its hot and neutral leads properly connected to hot and neutral leads of a utility circuit, a switch of the safety circuit connects the clamping device to be between ground and neutral leads of the power filter circuit, but when the hot and neutral leads of a utility circuit are reversed, the switch of the safety circuit connects the safety circuit directly between the neutral and hot leads of the power filter circuit, thereby creating an indicator, such as a red light, that the hot and neutral leads are reversed, yet the clamping device is now not connected between the neutral and ground leads of the power filter circuit. Accordingly, the clamping device connected between the ground and neutral leads may be rated during normal operations at a lower value, e.g.

Abstract: A substation includes standard arresters installed near a bushing of a power transmission line entrance and at a connecting bus of a transformer and one or more high voltage arresters having a discharge voltage 10 to 30% higher than a standard arrester. Each high voltage arrester uses zinc oxide elements and is disposed on a line side of a line entrance breaker and/or near an open end of a double main bus in the substation.

Abstract: A surge arrester includes varistor elements forming a stack and having opposed end surfaces. The varistor stack is electrically connected via the opposed end surfaces to end terminals having circumferential ridges, which, in the event of failure of the varistor elements, are designed to relocate the resulting arc and direct it in a manner which reduces or minimizes damage to the surge attester. The ridges serve as damage-tolerant sacrificial rooting points for an arc in the event of varistor element failure by presenting a substantial metal mass for the arc to erode away.

Abstract: An improved surge arrester includes metal oxide varistors in series with spark gap assemblies arranged such that the MOV elements conduct the low magnitude, steady-state current through the arrester along a path that is separate and distinct from the path through which impulse current is conducted during an overvoltage.

Abstract: A modular electrical assembly including a plurality of conductive electrical components aligned in a column along an axis and electrically connected at axially directed ends. First and second conductive end members are located at opposite sides of the column, the end members having shoulders extending radially relative to the axis, each shoulder having an outer surface facing radially outwards. A non-conductive winding is wrapped in a predetermined pattern about the electrical components and the end members, engaging the shoulders, and applying an axially directed compressive force through the shoulders on the electrical components and end members to maintain electrical connection therebetween. A housing encompasses the winding, while a strip, located between the housing and the winding, covers the outer surface of the first end member to protect the housing from contact with the outer surface of the shoulders. The strip also covers voids between the first end member and the non-conductive winding.

Abstract: A surge arrester has a single varistor element or a stack of varistor elements held between two end terminals by a plurality of elongate strength members disposed therearound. The ends of the strength members are inserted into recesses in the end terminals. Crimping of the end terminals distorts the recesses sufficiently to hold the strength members firmly therewithin, but without shearing and crushing (or otherwise damaging) the strength members.

Abstract: The discharge capability of zinc oxide elements is determined. A current of a given energy quantity is allowed to flow through a zinc oxide element to generate heat. The element is photographed by a camera and the temperature distribution of the element is obtained from the photographed image. The maximum temperature and the minimum temperature are determined and simultaneously the distance l between the points which show both the temperatures is determined. The difference .DELTA.T between the maximum temperature and the minimum temperature is divided by the distance l to obtain an index .DELTA.T/l. The relation between the index and the discharge capability is previously obtained and this relation is stored in a memory. Using the stored relation, a discharge capability corresponding to the obtained index is obtained.

Abstract: An overvoltage protection apparatus is used with a pair of telephone or communications TIP/A and RING/B lines including voltage clamping circuitry for clamping voltage signals on the lines at a predetermined voltage potential. The voltage clamping circuitry includes a pair of voltage clamping devices connected in series between the TIP/A and RING/B lines and a third voltage clamping device connected between a junction connection of the pair of the voltage clamping devices and a ground potential connection and current limiting devices for limiting current flow in the lines. The predetermined voltage potential exceeds a primary alternating current (AC) power line peak value by a set tolerance value.

Abstract: An improved line arrester is disclosed that includes a non-linear resistor. The arrester includes a pair of arcing horns are respectively provided on an earth side and a line side of the arrester, with an aerial discharge gap being provided therebetween. The aerial discharge gap is in electrical parallel with the resistor. The length of the aerial discharge gap is selected such that flashover does not occur in response to currents smaller than a rated discharge current of the resistor, yet flashover does occur in response to a current that is greater than the rated discharge current, but lower than a critical discharge current of the resistor. With this arrangement the resistor is protected against the lightning surge current greater than the critical discharge current.

Abstract: A lightning arrester module is double-enclosed to insure adequate environmental protection to the enclosed varistors as well as to contain the internal components of the arrester upon severe fault conditions. The internal components including the varistors are compressed within one half section of the inner enclosure and can be handled and tested without disengagement. The other half section of the inner enclosure is positioned over the internal components to complete the inner enclosure before the outer enclosure is arranged thereover to complete the lightning arrester module assembly.

Abstract: A fragmentation resisting core unit adapted for installation within a surge arrester outer housing and including a conventional array of non-linear core components arranged in series along a core axis between the inner faces of a pair of end terminals with adjoining faces of the array subjected to sufficient compressive force that the compressed core array is electrically conductive. This core array under compression is circumscribed by a plurality of untensioned, high tensile strength annular bands of an insulant longitudinally circumscribing the compressed core array in mutually transverse planes with each reinforcing band extending longitudinally of the compressed electrically conductive core array in a manner to overlie the outer end face region of each end terminal in a closely adjoining relationship.