Abstract: A control switch is connected to a power supply voltage and turns on based on a control signal to output a current. A clamp circuit is connected to a load and performs clamp control of the output voltage of the control switch. A current control element conducts or shuts off a current based on the output voltage to be clamp-controlled. A selector switch group includes switches, and performs switching based on a voltage varying with the current control by the current control element, thereby switching between paths for generating an internal power supply. The switch circuit connects or disconnects the coupling between the clamp circuit and the selector switch group.

Abstract: A current transformer configuration includes a primary part and a secondary part. The primary part is surrounded by a housing. The housing has a first conductive housing part and a second conductive housing part. An electrically insulating gap lies between the two conductive housing parts. The housing passes through the secondary part. The electrically insulating gap is bridged by a surge protection configuration.

Abstract: Several embodiments of a novel technique for limiting transmission of fault current are disclosed. Current power distribution systems typically have an impedance, or reactor, on the output of the network equipment to limit current in the case of a fault condition. A low resistance switch, which changes its resistance in the presence of high current, is connected in parallel with this reactor. Thus, in normal operation, the current from the power generator bypasses the reactor, thereby minimizing power loss. However, in the presence of a fault, the resistance of the switch increases, forcing the current to pass through the reactor, thereby limiting the fault current.

Abstract: The present invention relates to a lightning protection apparatus using a TN-C common ground. A lightning protection apparatus using a TN-C common ground according to the present invention, which is disposed between a power source part and load facilities and is connected in series thereto in order to protect the power source part and the load facilities from lightning, includes: an input part surge protection circuit connecting to the power source part; an output part surge protection circuit connecting to the load facilities; a double winding transformer having a primary part and a secondary part, which connect to the input part surge protection circuit and the output part surge protection circuit, respectively; and common ground members connecting, respectively, to the input part surge protection circuit, the double winding transformer, the output part surge protection circuit, and the load facilities such that electric potentials applied to all of the former are the same as a reference electric potential.

Abstract: The invention relates to an on-load tap changer for switching among winding taps of a step transformer without interruption. According to the invention, in each auxiliary current branch of the on-load tap changer, which operates with vacuum switching tubes as switching elements, additional switches are provided in series with the vacuum switching tubes and the respective winding tap. Said additional switches cause a complete galvanic isolation of the vacuum switching tubes in the auxiliary current branches in steady-state operation.

Abstract: A current transformer configuration includes a primary part and a secondary part. The primary part is surrounded by a housing. The housing has a first conductive housing part and a second conductive housing part. An electrically insulating gap lies between the two conductive housing parts. The housing passes through the secondary part. The electrically insulating gap is bridged by a surge protection configuration.

Abstract: A surge preventing circuit of a local area network (LAN) connector is suitable for being coupled to a plurality of transformers disposed in the local area network connector. The surge preventing circuit includes a conjugate coil module and a surge absorbing element. The conjugate coil module has at least one conjugate coil. The conjugate coil has a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The first input terminal and the second input terminal of the conjugate coil are coupled to the center tapped terminal of the respective transformer, respectively. A first terminal of the surge absorbing element is connected to ground, and a second terminal is coupled to the first output terminals and the second output terminals.

Abstract: Resettable circuit interrupting devices, such as GFCI devices, that include reverse wiring protection, and optionally an independent trip portions and/or a reset lockout portion are provided. The reverse wiring protection operates at both the line and load sides of the device so that in the event line side wiring to the device is improperly connected to the load side, fault protection for the device remains. The trip portion operates independently of a circuit interrupting portion used to break the electrical continuity in one or more conductive paths in the device. The reset lockout portion prevents the reestablishing of electrical continuity in open conductive paths if the circuit interrupting portion is non-operational or if an open neutral condition exists.

Abstract: A structure for installing a lightning arrester between the cross arm mounted to the upper end of an electric pole and a power line is disclosed. A dead end clamp, the lightning arrester and an insulation reinforcing insulator are connected in series, an end of the insulation reinforcing insulator is connected to the cross arm by a shackle, a disconnector is connected to the voltage outlet portion of the lightning arrester, a grounding wire for diverting abnormal voltage to the ground is connected to the disconnector, and an insulation cover surrounds the dead end clamp and the voltage inlet portion of the lightning arrester.

Abstract: There is provided an inductive coupler for coupling a signal to a power line. The inductive coupler includes (a) a magnetic core having an aperture through which the power line is routed, (b) a winding wound around a portion of the magnetic core, where the signal is coupled between the winding and the power line via the magnetic core, and (c) an electrically conductive member on an exterior of the inductive coupler that provides a path to electrical ground for a flashover current.

Abstract: An earthing device which needs not be buried under the ground is provided. The earthing device includes an earthing panel and a discharging device mounted inside the earthing panel. The discharging device includes at least one electrode plate, multiple discharging electrodes coupled to the electrode plate, and catalyst filled between the discharging electrodes. Since an earth electrode needs not be buried under the ground, it requires less construction costs, time and area, and environmental pollution (especially, soil pollution) does not happen. Further, the earthing device can be simply and economically installed regardless of place.

Abstract: Embodiments test MOV arresters. One embodiment comprises applying a plurality of voltages to a high voltage lead of the MOV arrester, the plurality of voltages being changed between an initial test voltage and final test voltage (corresponding to a point of conduction of a reference MOV arrester); determining a resistive current through the MOV arrester for each of the voltages; determining information corresponding to the resistive current when the applied test voltage corresponds to the point of conduction of the reference MOV arrester; comparing the determined information with information associated with the point of conduction of the reference MOV arrester; determining that the MOV arrester has passed the test when the determined information corresponds to the information associated with the reference MOV arrester; and determining that the MOV arrester has failed the test when the determined information does not correspond to the information associated with the reference MOV arrester.

Abstract: Disclosed is a surge-protected layout for a printed circuit board useful for either through-hole or surface mount circuitry. A special arrangement of a ground trace on the board relative to the signal traces on the board reduces the damaging effects of over-voltage events to circuit components. More specifically, the arrangement is such that the ground trace is etched to encourage sparkover from the signal traces on the board by conforming parts of its perimeter to parts of the perimeters of the signal traces on the board. This has the effect of increasing the reliability of electrical and electronic circuitry, reducing repair and replacement costs of the same, and reducing equipment downtime due to over-voltage events.

Abstract: A mounting construction of a tank-type lightning arrester for a neutral point of a transformer includes a transformer having a transformer winding contained within a transformer tank, the transformer winding having a neutral point, and a tank-type lightning arrester having an overvoltage protection element contained within a lightning arrester tank. A first opening is formed in an upper portion of a side surface of the transformer tank, and a second opening is formed in the lightning arrester tank, and the first and second openings are connected together through an insulating spacer having a central conductor, and the neutral point of the transformer winding is connected to the overvoltage protection element via the central conductor. The lightning arrester tank is supported solely by a mounting portion provided on a side surface of the transformer tank.

Abstract: An improved surge protecting circuit which can protect the power source and the internal and external circuit elements of an electronic product by absorbing external surges through ground. The protecting circuit according to the present invention is connected between an AC input terminal and an AC ground pattern. The protecting circuit includes surge absorption patterns having an arc discharge gap of preferably 0.25 mm, which is less than a specified safety distance, which is typically 5 mm, so as to absorb the external surges transmitted through the terminal to the AC ground pattern and a varistor connected between the surge absorption patterns and the AC ground patterns.

Abstract: The arrestors of a compact gas insulated switchgear are to be connected to gas insulated main buses. The arrestors represent three phases, and are arranged in such a manner that the distance from a main bus which is located at the outermost position among a plurality of main buses to at least one arrestor for one phase is differentiated from the distances from the outermost main bus to at least one of the remaining arrestors. As a result, the area or the width required for installing the arrestors is minimized, the length of the main buses is shortened, and the installation area of the gas insulated switchgear as a whole can be reduced.

Abstract: A circuit arrangement having the function of preventing over-voltage damage which is structured by special copper foil or conductive wires and applies the burst absorption principle to form a short circuit from the input end and the output end of a circuit when the circuit is subject to an over-voltage or a transient electrical strike, so as to protect the electronic elements within the area of the circuit. The method can be put into application in a transformer, a switching power supply, an electronic computer, a solid-state relay and other similar electronic equipment. The arrangement of the present invention has undergone a number of high voltage and electrical striking tests with more than satisfactory results and is suitable for use in industries.

Abstract: A flexible printed circuit board for use in a display unit of a camera, which includes a flexible substrate with a printed circuit pattern, a die of an integrated circuit chip mounted on said substrate for driving the display drive, a plurality of wires, and resin sealant for covering said integrated circuit chip. The flexible substrate has first terminals to be in contact with a display device and second terminals in electric connections to said first terminals, respectively. The die of the integrated circuit chip includes a plurality of connecting terminals. The plurality of wires are for bonding said connecting terminals of the integrated circuit chip to said second terminals of said printed circuit pattern.

Abstract: A transformer including a bobbin having a primary winding frame and a secondary winding frame, a primary coil wound around the primary winding frame, a secondary coil wound around the secondary winding frame, a pair of connection pins electrically connected to a power source A projection which can be broken or bent is provided on the bobbin. The wire of the primary coil is hitched over the projection and then wound to form the primary coil, and the projection is therafter broken or bent to loosen the primary coil. A discharge means is also provided to cause a discharge between the pair of connection pins when a high voltage is applied therebetween.

Abstract: A lightning surge protector, comprises a current limiting element in a pressure-proof housing. The pressure-proof housing is composed of a conductive material and coupled with an upper electrode member. Also, a self arc-extinguishing LSP comprises a current limiting element and upper and lower electrode members housed and fixed in a conductive pressure-proof housing opened at its lower portion through a suspension structure composed of a suspension rod. The outside and inside of the housing are covered and filled with an insulator, so that, upon occurrence of an internal arc due to a short-circuit fault or the like, the energy due to the arc causes the lower electrode member to break the insulator in the vicinity of an opening portion of the conductive pressure-proof housing so as to electrically connect the conductive pressure-proof housing to a part of the lower electrode member.

Abstract: A system and device are disclosed for protecting the primary windings of a distribution transformer from surge current which exceed a predetermined level including a tank for accommodating the distribution transformer, a first expanding arc gap extending between a first terminal and a second terminal on the secondary side of the distribution transformer, and a second expanding arc gap extending between a third terminal and the second terminal on the secondary side of the distribution transformer. The arc gap being mounted within the gas space of the tank which accommodates the distribution transformer such that a surge current which exceeds the predetermined level is directed through the arc gaps and dissipated by the expanding arc gaps thereby bypassing the secondary windings in order to protect the primary windings of the distribution transformer. The internally mounted arc gaps being effective when applied to either interlaced or non-interlaced distribution transformers.

Abstract: A portable tester is disclosed for determining in the field the condition of a lightning arrester connected in parallel with a high voltage winding of a transformer. The tester comprises a battery; an inverter connected to the battery for generating an AC output; at least one transformer and a rectifier for transforming the output of the inverter to a high voltage DC having a magnitude greater than the breakdown voltage of a lightning arrester connected in paralled to the high voltage winding of a transformer being tested; at least one capacitor connected across the rectifier for being charged to the high voltage DC; an overvoltage spark gap switch for discharging the high voltage charge of the capacitor across the high voltage winding of the transformer being tested; and a storage oscilloscope for detecting the response of the winding to the high voltage pulse. A normally functioning lightning arrester will clamp the voltage across the transformer winding at the arrester's known breakdown point.

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: A switching apparatus (30) provides a normally high impedance connection which is capable of switching currents with high magnitudes and high rates of rise between the primary (12) and secondary (15) neutrals of a service transformer (13), such as that used to supply power to a farmstead, such that undesirable voltages appearing on the primary neutral line are not transmitted to the secondary neutral. Upon the occurrence of a fault at the distribution transformer, or a surge on the power line, the switching apparatus (30) rapidly switches to provide a low resistance connection between the primary and secondary neutrals so that any fault current passing from the primary to the secondary of the transformer will be shunted back to the primary neutral.

Abstract: This dual voltage transformer comprises a primary winding having a tap at a location intermediate its length, a first termination for connection to line voltage, and a second termination for connection to ground. When the transformer is to be operated at a relatively high voltage, the first termination is connected through a dual voltage switch to line voltage; and when the transformer is to be operated at a relatively low voltage, the tap is connected through said switch to line voltage. First varistor means is connected across the primary winding between said first and second terminations both when the transformer is operated at high voltage and at low voltage; and second varistor means having a lower breakover voltage than the first varistor means is connected between said tap and ground when the transformer is operated at low voltage.

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

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: Electrical distribution apparatus, such as a pad-mounted electrical distribution transformer, which has an electrically grounded tank or casing. A surge arrester assembly includes a housing, and a draw-out surge arrester having first and second insulatively spaced electrical contacts, with the draw-out surge arrester being removably disposed in the arrester housing. The arrester housing has first and second insulatively spaced metallic end members, with the first metallic end member functioning as a mounting structure for mounting the arrester housing in a tank opening, and as an electrical contact which automatically connects the first electrical contact of the draw-out surge arrester to the grounded tank of the apparatus to be protected. The second metallic end member of the housing electrically connects the second electrical contact of the draw-out surge arrester to an electrical circuit point within the tank to be protected against voltage surges.

Abstract: A dual voltage distribution transformer is protected by an internally installed, multi-rated surge arrester which is selectively connected with plural primary windings by a dual voltage switch such as to establish a high surge voltage protection level when the primary windings are connected in series by the switch and a correspondingly lower surge voltage protection level when the primary windings are connected in parallel by the switch.

Abstract: A spark arrestor for protecting a high intensity, gaseous discharge lamp, ballast and other circuit components against being damaged or destroyed by a large build up of voltage. The arrestor includes a multi-sided low dielectric disc with star-like conductive material on each side, the points of the star being opposite the mid-points of the sides. Terminals for connecting the spark arrestor across the secondary of the ballast, or other similar location, are connected to each of the star-like conductive materials. There is a non-conductive tubular shield around the disc to protect againt spreading of the spark, but the terminals extend from the ends of the shield for connection purposes.

Abstract: A guard for a high voltage terminal bushing includes a generally circular planar isolating member of an electrically insulating material which is mounted on the upper surface of the bushing and provided with a plurality of openings through which wind and rain may freely pass. A radial diameter of the isolating member is sufficient to prevent small animals from contacting a high voltage cable connected to the bushing and ground potential. A cylindrical section extends downwardly from the isolating member to support the guard on the upper surface of the bushing. A second cylindrical member extends downwardly and surrounds the upper portion of the bushing to form a cap to protect and shield the terminal end of the bushing. A lightning arrestor may be included which extends from adjacent the high voltage terminal to a point adjacent a transformer housing or ground potential.

Abstract: Zinc oxide varistor protective devices for vapor cooled transformers are integrally located in contact with the transformer coolant liquid to provide cooling capacity to the zinc oxide materials. The zinc oxide varistors are prevented from becoming electrically unstable by keeping the varistor operating temperature at or below the boiling point of the coolant.

Abstract: A lightning arrester is mounted on one end of a rigid insulator bar, the other end of which is mounted by a metal bracket to the grounded casing of an electrical distribution transformer. The ground terminal of the arrester is electrically connected with a terminal on the insulator bar intermediate the arrester mounting and the transformer mounting. A switch is remotely operable to establish electrical communication between the transformer casing and the intermediate terminal, and thus to the ground terminal of the lightning arrester.