Abstract: A surge suppressor disconnect protection circuit is coupled to a first surge suppressor electrically coupled to the terminals of an AC source to protect the first surge suppressor from predetermined overvoltages. The circuit includes a relay switch connected in series with the first surge connected to the AC source terminals for rectifying the 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 and to and providing a difference signal integrator time constant is electrically connected to the amplifier and produces a signal which is proportional to a length of time the scaled DC signal is greater than the first voltage reference. A comparator is connected to a second voltage reference. The comparator output is electrically coupled to the relay switch which opens the switch contact to set it to a high impedance state when the integrator output signal exceeds the second voltage reference.

Abstract: A surge arrester includes a stack of varistor blocks (10), for example of zinc oxide, arranged between two end electrodes (11, 12) in an elongated insulating casing (23) of polymeric material, for example silicone rubber. The varistor blocks and the electrodes are axially surrounded by compression loops (14-17) of insulating material for providing the necessary contact pressure between the different elements (10, 11, 12) in the varistor stack. The varistor stack (10) and the compression loops are radially surrounded by a bursting-preventive bandage (21) of insulating material with openings (22) for pressure relief in case of internal short circuit in the surge arrester.

Abstract: A surge arrester includes at least two connection fittings and a one-piece frame, the frame holding the connection fittings. The frame is formed of an insulating material. The surge arrester includes at least one block of varistor material clamped between the connection fittings. The surge arrester further includes an insulating material in which the frame, the block of varistor material and at least part of the connection fittings are cast to form a monolithic body. An arrangement is provided for maintaining a contact force between the connection fittings and the block of varistor material.

Abstract: A surge arrester having a cylindrical housing with a throughbore, a metal terminal at each end of the housing, varistor elements located within the housing bore, and a vent within at least one terminal for venting arc-generated gases from the interior of the housing in the event of an arc being developed within the bore as a result of failure of a varistor element. The vent can be formed as a passage extending through one of the terminals from the bore to the exterior thereof via a substantially straight-line path that extends longitudinally of the bore. An electrode connected to the other terminal is spaced from the one terminal by a gap located externally of the insulating housing. The gap arcs over in response to receipt of arc-generated gases from the bore. The gap is located at the end of the housing of the one terminal.

Abstract: In a surge arrester with a multi-column arrangement of the metal oxide resistors within an insulating housing, each column is to be made of resistance elements in a mechanically self-supporting structure. To this end, the resistance elements of each column are arranged between two holding plates intercon-nected by holding rods. The individual columns, called "modules", are arranged to be individually centered on a plate fitted at the lower end of the insulating housing.

Abstract: A surge arrester (1) for high voltage has a porcelain housing (2) with safety shields (3, 4, 7, 8). In the central area along the longitudinal axis of the surge arrester (1), safety shields (3) with a larger diameter may alternate with safety shields (4) having a smaller diameter. The surge arrester (1) has blow-out apertures (5) at its ends, and gas under high pressure flows out of these apertures in the event of a-short-circuit current. To protect the safety shields from damage, the safety shields (7, 8) that are closest to the blow-out apertures (5) are constructed with smaller diameters than the other safety shields.

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: In order to provide an arrestor for a gas insulated switchgear in which the voltage share rates of respective zinc oxide non-linear resistance elements are made uniform, in an arrestor constituted by a plurality of columns for a gas insulated switchgear, the thickness or the capacitance of insulator spacers contacting the high voltage terminal or the ground terminal in respective columns is controlled, whereby the potentials of the zinc oxide non-linear resistance elements close to the high voltage terminal or to the ground terminal in the respective columns are shifted close to the potentials of the high voltage terminal or the ground terminal.

Abstract: It is an object to provide a lightning arrester having machinery built-in in which an axial length of an insulating tube which stores therein zinc oxide elements is reduced so that an attempt is made for miniaturization. The arrangement is as follows. That is, a metal cap with an inclination portion 11 which is fixed to one end of the insulating tube 4 which stores therein the zinc oxide elements 5 is made to a dish shape which projects toward the anti-side of the zinc oxide elements, openings 11a are formed in the inclined portion thereof so that the inside and the outside of the insulating tube 4 communicate with each other, an insulating medium is circulated through the openings 11a while a sufficient gap L is formed between the one end of the insulating container 4 and a ground bracket 15, and the zinc oxide elements 5 are cooled by the insulating medium.

Abstract: An over-voltage protection plug for telecommunication installations, including a housing with a printed-circuit board, a voltagesurge suppressor, a slider, a spring, an earth plate, a signalling element. Reliable protection against voltage surges is provided, wherein the solder position is loaded to a minimum extent only. The plug is composed of few parts only and further permits automated manufacture at low cost, and which clearly shows the tripped condition at the outside. The slider is pre-loaded over a support face and over an edge at the inner housing wall in the housing by the spring. A shaped part of solder material is loaded to a minimum extent only by the spring force (pressure force) of the slider.

Abstract: A socket adapter housing has a plurality of line and load blade terminals and jaw contacts. An electrical power disconnect device, mounted in the housing, has contacts switchable between closed and open states, the contacts being serially connected between the line blade terminals and the line jaw contacts. Rigid bus bars are fixedly connected to terminals on the power disconnect device extending from the switchable contacts and to the line blade and line jaws to fixedly mount the power disconnect device in the socket adapter housing. Surge suppression devices are connected between the load blade terminals and ground potential. An insulating safety shield is mounted in the housing and completely surrounds the line and load jaw contacts. Alternately, the housing includes a watthour meter receiving portion containing the power disconnect means and the line and load blade terminals and jaw contacts.

Abstract: A surge protector for coupling exposed (to power surges) data communication end ports having a plurality of bi-directional data lines, and protected data communication end ports having a plurality of associated bi-directional data lines. The surge protector includes a plurality of exposed end terminals, each exposed end terminal for connection to a data line of the exposed port, and a plurality of protected end terminals, each protected end terminal for connection to an associated data line of the protected port. The surge protector includes a plurality of transient surge protection elements. Each transient surge protection element is connected across one exposed terminal and a ground, and short circuits current to ground when voltage on the exposed terminal reaches a threshold limit. The surge suppressor also includes a plurality of opto-isolation elements, each connected between a connection for a transient surge suppressor element and a protected terminal.

Abstract: A surge arrester with an elongated polymer housing (1) includes a stack of arrester elements (2), for example of zinc oxide. To limit the radial voltage stress which may arise in the polymer material upon pollution, the polymer housing (1) is provided on the outside with field-equalizing control electrodes (6) in the form of bands or rings of metal at regular distances along the arrester. The control electrodes (6) are electrically connected to the ZnO stack (2, 3) inside the housing (1).

Abstract: The grounding tank 2 is laid on its side in the state that the covers 7A and 7B of the openings 3A and 3B at the both ends thereof are removed and the truck 8 is turned so that the side frame 8b on the back of the truck 8 and the bottom 8a with the wheel 11 are reversely positioned so as to mount the divided arrester units 7A and 7B to the tank 2 and the cover 7A (7B) and each arrester unit 4A (4B) are mounted and fixed to the side frame 8Ab, 8Bb so that they can be mounted and removed in the integrated state. The cover 7A (7B) and each arrester unit 4A (4B) are lined up in a horizontal line at the same height as that of the openings 3A and 3B of the grounding tank 2 after the truck 8 is turned and returned to the normal posture. The arrester units 4A and 4B are inserted and set into the grounding tank from side by moving the trucks 8A, 8B and the covers 7A and 7B are removed from the truck 8A, 8B and mounted on the tank 2 side so that they close the openings 3A and 3B at the same time.

Abstract: A gap-type surge absorbing element and a varistor are assembled end to end in an insulating tube to form a compact surge absorber. Electrodes on the two devices contact a intermediate element to provide electrical connection therebetween. End electrodes seal the insulating tube and provide external connection to the outboard ends of the two devices, thereby putting them in series. The interior of the insulating tube is filled with an inert gas. Embodiments are described using microgap-type and gap-type surge absorbing elements.

Abstract: A current-limiting protector package for use in conjunction with telephone terminal blocks comprises a two-piece interfitting housing which is made up of two housing halves soncially welded together. A pair of tip or ring terminals is disposed within each housing half along with a current-limiting device in the form of a positive-temperature-coefficient (PTC) device of the conductive polymer type. Lower end portions of the tip or ring terminals project outwardly from the housing so as to be capable of electrical engagement with opposed sets of terminals provided upon the telephone terminal block, while upper end portions of the tip or ring terminals project outwardly from the housing so as to be accessible to a line test probe whereby the lines or circuits of the telephone terminal block can be tested in connection with their operative status without necessitating removal of the protector package from the terminal block.

Abstract: Protective circuit with a threshold circuit for discharging overvoltage surges to ground and with a low-value resistor positioned in a line wire at the subscriber's end meets a higher level of lightning protection by connecting a voltage-limiting component (V1, V2) in parallel with the low-value resistor (R1, R2). Such may a varistor connected in parallel with each of the series low-value feed or sensing resistors. The invention meets symmetry requirements, places low voltage requirements on low-value resistors and preceding parallel components, makes use of inexpensive voltage-limiting components and thereby results in cost saving.

Abstract: To enable the mounting of arrester in a small-sized package of a resin-sealed type for general use, such as a T0-92 package or a T0-220 package, by modifying the arrangement of diodes and thyristor there is provided: a diode-bridge thyristor type of semiconductor arrester, comprising: a pair of opposed metal plates (20, 21); a thyristor (T1) between the metal plates (20, 21); three pairs of diodes (D1, D2: D3, D4: D5, D6) between the metal plates (20, 21); and three leads (22, 23, 24), each provided between each pair of diodes.

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. The uniform performance characteristics allow MOVs to be utilized parallel more successfully, eliminating many of the previous problems encountered. Instead of attaching wires to each MOV, the MOVs are packaged by placing them between a pair of contact plates, preferably manufactured from aluminum. The pair of plates are connected together and tensioned using non-conductive nuts and bolts. 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. Additional plates can be utilized to increase surge arrestor surge current capability.

Abstract: The surge arrester contains two connection fittings (1, 2) which are spaced apart from one another along an axis and between which at least one cylindrical varistor element (7) is arranged. The connection fittings (1, 2) and the at least one varistor element (7) are clamped with one another, accompanied by the formation of contact force, to form a mechanically stable active part of the surge arrester. The active part is surrounded by a cast housing (12) made from insulating material. The clamping of the active part is achieved by at least two loops (5) respectively acting independently of one another on the connection fittings (1, 2). The loops (5) are arranged at a distance from the at least one varistor element (7). The connection fittings (1, 2) contain bearing areas which correspond respectively to the number of the loops (5) and are distributed uniformly about the axis azimuthally and on which a loop end is respectively supported.

Abstract: A secondary surge arrester has a line conductor and a ground conductor extending through a casing. A nonlinear voltage dependent resistive element and a fault current limiting fuse are connected between the conductors and are disposed within the casing. The fault current limiting fuse includes a fusible material surrounded by sand. The sand also surrounds the nonlinear voltage dependent resistive element. A heat sensitive material is disposed in close proximity to the fusible material and is viewable through a transparent cover. In the event of a failure of the nonlinear voltage dependent resistive element causing arcing, the fusible material fuses to open the current path between the conductors, and the sand absorbs energy by transforming state. Thus, the fault current limiting fuse limits current flow through the surge arrester and extinguishes the arc within the surge arrester so as to prevent violent fragmentation of the casing.

Abstract: A protector arrangement is disclosed having first and second protector terminals, a gas discharge tube, and a metal oxide varistor. The gas discharge tube is connected to the first and second protector terminals. The metal oxide varistor is connected to the first and second protector terminals so that the metal oxide varistor acts as a backup to the gas discharge tube and so that the first and second protector terminals are automatically shorted in response to a thermal overload condition. The protector arrangement may be mounted in a weathertight housing.

Abstract: Surge protection for a data transmission line, typically a telephone line including two data signal conductors, incorporates a primary protector circuit for high voltage, high energy surges and a secondary protector circuit for low voltage surges. The primary protector circuit includes a normally non-conductive "breakdown" or "crowbar" device having a high breakdown voltage, a solid-state triac, or a thyristor, driven conductive by a surge exceeding its breakdown voltage; the crowbar device is connected from one or both conductors to ground. An inductance is connected in the circuit to extend the time in which the circuit reduces a surge to near zero voltage, and thus dissipates power from the surge. The second protector circuit includes at least one avalanche diode, Zener diode, or other threshold device in parallel with the primary protector circuit.

Abstract: A miniature station protector module for communication systems includes a hollow housing having a top surface and open bottom. A pair of line terminals and ground terminals are disposed in the housings top surface and extend inside the hollow housing, with the ground terminal disposed intermediate the pair of line terminals. A non-conductive printed circuit board with conductive paths thereon is affixed to the pair of line terminals and the ground terminal. A holding assembly is affixed to the ground terminal within the hollow housing and is adapted to receive a surge arrester therein. The surge arrester has at least a pair of electrodes and a ground terminal, with the ground terminal being an electrically conductive contact with the housing ground terminal, each one of the pair of surge arrester electrodes are in electrically conductive contact with one of the pair of line terminals. A protective housing circumscribes the surge arrester means and portions of the holding assembly means.

Abstract: A transient voltage surge suppressor (100) for use in a single or poly-phase power distribution network to protect equipment supplied power from the network from damage caused by line surges or transients. A plurality of surge suppression assemblies (102A-102G) each of which includes a plurality of semiconductors (114) connected in parallel and a fuse wire (118) connected in series with each semiconductor. Each assembly is mounted on a separate circuit board (126A-126G). A fault detection circuit (104) in each assembly includes both a sensor (132A-132G) for sensing when a semiconductor in one of the surge suppression assemblies fails, or when a fuse wire in one of the assemblies clears, and a circuit (152) for providing a visual indication thereof. The fault detector is mounted on a separate circuit board (131).

Abstract: An electrical overstress protection composite of electrical conductor/semiconductor particles including particles in the 100 to 10 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: An ESD protection structure for p-well technology using nMOS FETs that prevents the lock-on condition normally occurring after one FET of a multi finger structure snaps back. The multifinger structure is contained in a main p-well and channels ESDs of a first polarity from the contact pad to a metal conduit. A resistance is provided between the main p-well and the conduit. Further, the circuit channeling ESDs of a polarity opposite to the first polarity is contained in a second p-well that is distinct from the main p-well. An ESD event causes one of the fingers to snap back. Resulting drain current through that finger generates electron hole pairs in the main p-well by impact ionization. Thus generated holes, traveling to the conduit through the resistance, raise the voltage of the main p-well, and therefore shift the i-v characteristic curves of all the FETs to a point where they no longer exhibit a knee.

Abstract: Thick-film varistors are made by melting and flame-spraying of precursor particulates onto circuit board substrate material already provided with conductive layers or laminae preferably on both sides. The resulting circuit boards are useful in transient voltage surge suppression (TVSS), such as in a TVSS watt-hour meter adapter.

Abstract: An electrical assembly having a surge arrester coupled in parallel to an insulator of high mechanical strength for increasing the mechanical strength of the surge arrester. The arrester having a plurality of non-linear resistive blocks positioned between a pair of end fittings and enclosed in a polymeric weathershed housing. The insulator having a reinforced fiberglass rod with a pair of end fittings and covered by a polymeric weathershed housing. The end fittings of the surge arrester and the insulator being rigidly coupled together by a pair of mounting plates for maintaining the surge arrester parallel to the insulator, and thereby increasing the mechanical strength of the arrester.

Abstract: A transient voltage surge suppressor (10) is used in a single or poly-phase power distribution network (P). The surge suppressor connects in parallel between each phase (A, B, C) and neutral (N), each phase and electrical ground (G), and between neutral and ground. An improvement comprises an electrical circuit (30) for monitoring the loss of surge protection due to the occurrence of a current surge or voltage transient in a neutral-to-ground path (32). An MOV-type semiconductor (VR1) is connected in the ground-to-neutral path. The semiconductor is normally non-conducting, but switches into conduction when its voltage threshold is exceeded by a surge current or voltage transient. An excessive surge or transient causes the semiconductor to fail. Respective fuses (F1A, F2B) are connected in series with the semiconductor. These fuses clear (blow) upon a semiconductor failure to create an open circuit neutral-to-ground path.

Abstract: A single three-terminal chip-type surge absorber combines two or three semiconductor surge-absorbing elements with three electrode plates and resin-molding the combination. When more lines must be connected to an electronic device subject to a voltage surge, instead of mounting a plurality of surge-absorbing elements, which requires a substantial space and many mounting steps, a single surge absorber with a plurality of surge absorbing elements absorbs the voltage surge.

Abstract: A surge suppression device which fits over the end of an electrical plug and permits normal mating of the plug with the female receptacle. In the preferred embodiment, the device includes a body of metal-oxide varistor (MOV) material where one pin is connected to one plate on the MOV and another plug pin is connected to an opposing plate on the MOV. The MOV breaks down when experiencing excessive voltage levels to shunt potentially damaging voltages between the plug pins thereby preventing the spikes from reaching the protected equipment.

Abstract: The present invention provides a circuit for limiting voltage surges in load centers, panelboards and other electrical distribution devices. The circuit includes at least one high potential terminal adapted for connecting to at least one corresponding service line and a low potential terminal adapted for connecting to a low potential means. The circuit also includes a plurality of varistors connected in parallel to one another between each high potential terminal and the low potential terminal and a plurality of fuses corresponding in number to the plurality of varistors. Each fuse is connected in series to one of the varistors. Each fuse opens the circuit therethrough upon failure of the associated varistor. The circuit further includes monitoring the status condition of the fuses.

Abstract: A telephone line overvoltage protection method and assembly are provided. The telephone line overvoltage protection assembly includes a telephone line station protector having at least first and second threaded arrester wells coupled to a telephone line pair to be protected, an adapter base, and a plug-in type telephone line overvoltage protector module mounted to the adapter base and having TIP, RING and ground pins. The adapter base includes TIP, RING and ground sockets for removably receiving the TIP, RING and ground pins of the overvoltage protector. First and second mounting legs project from the adapter base for being fixedly inserted into the first and second threaded arrester wells. First and second electrodes extend from the first and second mounting legs for electrical connection with the TIP and RING sockets and the arrester wells.

Abstract: This overvoltage surge arrester has a tubular porcelain housing having a bore, metal terminals at opposite ends of the porcelain housing, stacks of metal-oxide varistor disks located within the housing in angularly-spaced relationship about the bore, and venting means within the terminals for venting gases from the housing should an electric arc develop within the housing as a result of failure of a varistor disk. First liners of electrical insulating material having relatively high thermal conductivity are sandwiched between the stacks and the bore for providing effective heat transfer between the stacks and the porcelain housing. Additional liners are disposed on the bore in locations angularly between the first liners. These additional liners are of a thermal and electrical insulating material, a major portion of which is a ceramic selected from the group of alumina, thoria, zirconia, zircon, and spinel.

Abstract: An arrester assembly for protecting a circuit from electrical switching and lightning surges includes an isolator and a surge arrester. The isolator has one electrically conductive terminal connected to a power line conductor. The other isolator electrically conductive terminal is connected by a flexible electrical conductor to one terminal of the surge arrester. The opposite electrical terminal of the surge arrester is connected by a conductive support to ground. The isolator, flexible conductor and surge arrester are connected in sequence and in series between the power line conductor and ground.

Abstract: An overvoltage protector for protection of telecommunication equipment having a pair of line terminals, and a respective pair of levers forming part of the ground circuit, with an overvoltage protective device bonded under tension between each line terminal and each respective lever. When an overvoltage destroys one or other device, or the bond between the line terminal and the respective lever disappears, that lever pivots about a single fulcrum under a force applied by a spring and the end of that lever contacts the line terminal. This ensures an electrically conductive relation between the line terminal and the ground circuit. As a result, the equipment to which the overvoltage protector is applied is protected from lightning and successive overvoltage occurrence.

Abstract: Transient voltage surge suppression (TVSS) meter adapter status indication perceptible by a nearby observer. When TVSS over-voltage protective means is on-line, a visible and/or audible signal is generated within the meter adapter housing and is transmitted to the exterior. Light emitted by an indicating lamp connected in series with the over-voltage protective element is transmitted to the exterior by means of a translucent rod to which the lamp is juxtaposed extending through the meter adapter housing wall and terminating just outside. Sound emitted by a buzzer similarly located is transmitted through the housing wall upon demand of an an observer outside, who actuates a normally open switch in series with the buzzer by juxtaposing a small magnet against the housing wall.

Abstract: The utilization of clusters of two or more metal oxide varistors (MOVs) connected in parallel for suppressing surges and transients. Particular embodiments are disclosed for both grounded and ungrounded power systems. Also disclosed are two-stage and multi-stage uni-directional and bi-directional suppressors. Uni-directional means that the suppressor is intended to be placed between a source and a load for the purpose-of preventing voltage surges and transients from being propagated from the source into the load. Bi-directional suppressors are intended to be placed between a source and a load and provide suppression in both directions simultaneously.

Abstract: A coaxial cable (10) is for use in a power distribution network (N). The cable connects a surge protective device (SPD) in parallel with feeder lines (W1, W2) of the network. The SPD senses voltage surges on the feeder lines and clamps the voltages to a level at which loads (LD) connected downstream of the SPD are protected from excessive voltage levels. An inner conductor (12) and an outer conductor (14) have a dielectric material (16) separating them. The inner conductor is a round conductor, and the outer conductor forms a hollow cylinder in which the inner conductor and insulation material fit. A ratio of the inner diameter (D) of the outer conductor to the diameter (d) of the inner conductor is approximately 1.05. Thus, the diameter of the inner conductor is relatively large compared with the inner diameter of the outer conductor. A relatively large diameter of the inner conductor serves to minimize the dc resistance of the cable. Also, the dielectric material has a permittivity in the range of 2.0-4.0.

Abstract: As a known "back-up device" for a gas-filled over-voltage arrester, a voltage-dependent resistor (6) is arranged centrally in a housing with the over-voltage arrester (1). The varistor (6) can, in this connection, be sealed with a moisture-repelling substance and it is arranged concentrically to a connecting pin (5) of the over-voltage arrester. By means of an auxiliary electrode (8) of annular disk shape placed on the varistor (6), an air gap (13) from the connecting pin (5) can be formed. The varistor, after its response, can be short-circuited via this air gap.

Abstract: An arrester for a gas insulated switchgear device includes a closed container filled with an insulating gas; a columnar piled body formed by piling up a plurality of zinc oxide resistance elements between a high voltage side terminal and a grounding side terminal disposed in the closed container; a plurality of potential equalizing rings electrically and mechanically connected to the high voltage side terminal of the columnar piled body, the potential equalizing rings being disposed in a discrete manner along the piling up direction of the zinc oxide resistance elements with a predetermined spacing distance while surrounding the outer circumference of the columnar piled body; and an intermediate electrode disposed around the columnar piled body at a position facing the potential equalizing ring located nearest to the grounding side terminal among the potential equalizing rings.

Abstract: A sealed vented surge arrester and method of manufacture is described wherein the valve elements are held under compressive loading while strength members including a moisture sealing void filling compound are pressed fit from the sides of the unit with a shed applied over it. The design achieves all the desirable features of tubular strength members with an ease of manufacture from utilizing half-shell or more members which can be applied from the sides along the longitudinal axis of the valve elements during manufacture to provide better void filling between the structural members and the valve elements.

Abstract: A zinc oxide type arrester including: four constitutional units electrically connected in parallel and a closed container accommodating the constitutional units. Each of the constitutional units includes a first columnar stack body composed by stacking zinc oxide elements and insulating spacers in a first predetermined order, a second columnar stack body composed by stacking zinc oxide elements and insulating spacers in a second predetermined order and a third columnar stack body composed by stacking zinc oxide elements and insulating spacers in a third predetermined order, the zinc oxide elements in the first, second and third columnar stack bodies contained in one constitutional unit are connected in series as a whole, and at least two of the three columnar stack bodies having same stacking structures in adjoining constitutional units are arranged to closely face each other.

Abstract: A surge protection device for low level electronic systems and especially conventional roadway traffic monitoring equipment connected to embedded roadway sensors, which includes, for each sensor, first and second stage common mode and normal mode surge arrestor circuits and which stages are connected by a common mode choke in series with the sensor circuit and monitoring equipment. The first and second stage surge arrestor circuits and choke are preferably mounted on surge arrestor circuit boards having enlarged conductive traces and peripheral ground contact surfaces which enable large surge currents to pass to ground when the boards are mounted to a common grounding backplane.

Abstract: An arrester assembly for arresting over-voltage conditions in electric circuits and for isolating an arrester element from possibly harmful effects of external forces applied to the arrester assembly comprises a hollow cup and an arrester element located within the cup for arresting over-voltage conditions. A plastic sleeve is disposed within the cup surrounding the arrester element for isolating the arrester element from the possibly harmful effects of external forces applied to the assembly. A spring may also be provided within the cup for further isolating the arrester element from such effects.

Abstract: A common mode lightning protection circuit includes a series circuit including a Y-capacitor and breakdown device connected between a current carrying input line and the frame ground of the power supply. This arrangement permits the ready application of current carrying line-to-frame ground dielectric tests needed to meet predefined safety requirements.

Abstract: A transient voltage suppression circuit consists of energy dissipation components with one end connected either to a line or a neutral wire of a power line and the other end connected to a reed switch which, in turn, is connected to ground. The reed switch, which is an encapsulated switch consisting of two metal strips with a gap between them, is in an open position, and accordingly, does not under normal operating conditions provide a path to ground for the associated energy dissipation components. The energy dissipation components thus do not conduct. When a transient having a sufficiently high voltage occurs between the line or neutral wires and the ground wire, it causes the reed switch to conduct momentarily, that is, spark, across the gap. The switch momentarily forms a path to ground and allows the associated energy dissipation components to shunt a transient current away from protected appliances.

Abstract: A monolythic surge suppressor includes a power source, an inductor coil, and a load in series with one another and in parallel with at least a first varistor. The first varistor and the inductance coil are formed into a single unitary laminated assembly having at least first and second terminations connected thereto. A second varistor can be connected in parallel with the first varistor and is connected to a third termination.

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.