Abstract: An electric protective device for protecting a cable, its termination or other apparatus from the effect of lightning strikes on an overhead line to which the apparatus is connected comprises a tubular insulator combined with a surge arrester and integrated by common terminals at the ground and high voltage ends. The insulator and the surge arrester are concentrically disposed about the conductor in a common insulated structure to eliminate connecting leads therebetween and the voltage drop which occurs across such leads during a rapid rise in current. The surge arrester may contribute all or part of the electrical stress grading required in the termination.

Abstract: A telephone line overcurrent protector adapted to be mounted on a circuit board is shown having a cup shaped housing in which a PTC element is placed with leads extending out of the housing through apertures in a bottom cover. The bottom cover is formed in one embodiment with a frangible diaphragm to provide guided pressure release upon catastrophic failure of the PTC element, in another embodiment with open apertures in the bottom cover and in yet another embodiment with means to mount a snap out member closing an aperture in the bottom cover, both for the same purpose of providing guided pressure release.

Abstract: An on-chip thermal shutdown circuit senses the average junction temperature of an integrated circuit device. The on-chip circuit generates a signal when the junction temperature exceeds a preset limit. This signal may then be used to control other circuitry such that the electrical shutdown of the integrated circuit device is enabled under conditions of excessive device temperature. In this manner, catastrophic device damage can be avoided and the host system can be notified of the existence of a fault condition.

Abstract: A rating plug-metering accessory for molded case circuit breakers of the type employing an electronic trip unit is in the form of a rating plug enclosure that is optionally installed in the circuit breaker cover. Besides setting the ampere rating of the electronic trip unit, the rating plug-metering accessory further provides direct readout of the current in any of the phases of a multi-phase power distribution circuit. The rating plug-metering accessory can be either factory-installed or installed in situ.

Abstract: In a system for transmitting an electrical power supply by means of an over-head power transmission line supported by power transmission towers, a fault such as a short-circuit fault and a ground fault is detected by providing optical current sensors having opto-magnetic elements and opto-electric field elements on respective conductors of the transmission line to detect a fault current and fault voltage on the basis of the Faraday's effect and Pockel's effect. Light beams passing through the elements are modulated by the magnetic fields induced by the currents passing through the conductors and the voltages on the conductors, and thus include information about the current and voltage. There is further provided a circuit for calculating a distance to a fault point in accordance with the detected current, voltage and a phase difference therebetween and a known impedance of the power transmission line.

Abstract: A drive circuit for a voltage driven type semiconductor device having a serial circuit of a resistor and a Zener diode. One terminal of the serial circuit is connected to an output terminal (collector) of the semiconductor device. An overcurrent flowing in the semiconductor device is detected based on a current flowing through the serial circuit and the presence or absence of a drive signal fed to the drive circuit from an external control circuit. The detection level of the overcurrent can be adjusted by the voltage of the Zener diode, and the quick detection becomes possible. This arrangement makes it possible to detect an overcurrent in the semiconductor device, and hence to detect a shortcircuit in a circuit connected to that device in a minimal time required, thereby reducing the energy consumed in the semiconductor device during the short circuit.

Abstract: A drive circuit for a current sense IGBT having, in addition to a fault discrimination operational circuit for detecting an overcurrent of the current sense IGBT, a capacitor operatively connected in parallel to the gate-emitter of the current sense IGBT, and a transistor for discharging the capacitor via a resistor. In case of short-circuit fault, an overcurrent is detected by the fault discrimination operational circuit, and the transistor is turned on via the operational circuit. The gate voltage of the IGBT is gradually declined to turn off the IGBT. This enables the IGBT to be protected from a transitional overvoltage across the collector and emitter of the IGBT.

Abstract: A transient suppression component includes a lead assembly adapted to permit in-line installation in a connector contact. One lead surrounds the other and is cylindrical for connection to the aperture tines of a connector ground plate. The other lead carries electrical signals between mating portions of the connector contact assembly. A transient suppression component body is connected between the feedthrough lead and the cylindrical ground lead.

Abstract: A miniature circuit interrupter for interruption of a primary circuit, the circuit interrupter formed or molded with a plug, connector or the like, the plug or connector being non-serviceable and the circuit interrupter therein being sealed and watertight.

Abstract: An electrical system for an automobile comprises a plurality of slave modules connected to one or more respective loads and/or sensors, a power bus connecting the slave modules to a power supply and a signal bus connecting the slave modules to a control module operable to remotely control the switching of power supplied to the loads by the slave modules and/or the sampling of signals from the sensors wherein at least one of the slave modules and/or the control means comprises a thick film printed circuit formed on a metal substrate. The system simplifies the wiring loom of a vehicle and provides circuits which are resistant to vibration and electrical interference.

Abstract: A method and system incorporating an integral power consumption monitor-circuit breaker panel for industrial or commercial buildings and facilities. The power consumption monitor-circuit breaker panel not only protects each end use within the building against harmful overloads, but also monitors peak power demands of each end use. Electrical current, voltage and phase information is provided by each monitor-breaker. This information is then fed to a processing circuit that provides a power consumption value. The power consumption value is then fed to recording device to provide a power consumption history for each end use. Each monitor-breaker is identified by its end use, as for example, by color coding. The monitor device of each circuit breaker is designed to provide a voltage that is proportional to the circuit load.

Abstract: To perform the long delay function of an electronic trip device, a quantity (TLR1) representative of the thermal current state varies proportionally to the difference (I.sup.2 -Is.sup.2) between the square of a value (I) representative of the current flowing in a conductor to be protected and the square of a current threshold (Is). This first quantity (TLR1) is used in combination with a second value (TLR2) to produce a tripping signal when the second value exceeds a preset value (TLR2max). The second quantity preferably increases proportionally to the square (I.sup.2) of the value representative of the current, when the first quantity exceeds a preset threshold (STLR1) and decreases, preferably exponentially, when the first quantity is lower than this threshold.

Abstract: A heat generating means, such a resistive element, is serially connected in a current-carrying conductive line, and a fusible link carrying current from said line is serially mounted between the line and said resistive element and is positioned in proximity to the heat generating means, to be heated by the heat from the generating means and to melt in response thereto, thereby breaking the serial connection in the current-carrying line. A spring means may be provided to urge disconnection of the serial circuit when the fusible link melts.

Abstract: A multipole circuit breaker, for example, a three pole circuit breaker, can detect a condition when less than all of the phases are open circuited to trip the circuit breaker. This reduces the tripping time and hence risk of damage to the electrical load. The circuit breaker includes a thermal trip unit and a phase sensitivity assembly that is interlocked with the bimetals included with the thermal unit. The phase sensitivity assembly includes one or more levers, responsive to the deflection of a bimetal corresponding to the open circuited phase resulting from cooling action of a bimetal relative to the other bimetals. The relative displacement of the cooling bimetal is used to either trip or reduce the tripping time of the circuit breaker.

Abstract: A sensitive and fast low voltage lamp system controller to provide safe operation of "bare wire" systems that are particularly attractive for use in exhibition and tradeshow booth lighting. The high sensitivity is achieved by emphasizing high frequency noise present during shorts and by proportionately limiting the instantaneous current that tracks the line AC voltage waveform; fast response is provided by a power FET coupled to a bridge rectifier in series with the load and both then in series with a protection relay.

Abstract: A panel, such as used to connect a building wiring system to a source of utility power, includes a voltage surge and transient protector network mounted directly thereon to be unitary therewith. The panel can be used as a stand alone panel, or in combination with other subpanels in an overall system. Each of the subpanels can include its own protector network, or can include further elements of the protector network partially included on the main panel whereby all of the panels in an overall system co-operate to form the voltage surge and transient protection network. The protection networks disclosed in U.S. Pat. Nos. 4,675,772 and 4,835,650 are integrated into panels to form protection networks. Enhancements for high neutral currents and isolated ground buses are included with the panel and protective elements in various forms of the invention.

Abstract: The present invention is directed to the grouping of contiguous floors in a building into sectors. According to the present invention, historical information regarding the number of passengers arriving at each floor is obtained and used to predict the number of passengers to be arriving at each of the floors. By summing the predicted traffic per floor and dividing by the number of sectors to be formed, average traffic per sector can be determined. In the preferred embodiment, sectors are formed, starting from the first floor above the lobby and continuing through to the top floor in the building, by selecting a set of contiguous floors for each sector such that the predicted traffic for each sector is less than a predetermined threshold. Specifically, if the predicted traffic for a selectable next contiguous floor, added to the predicted traffic for all contiguous floors already selected for the sector, is less than the predetermined threshold, the selectable floor is included in the sector.

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: The device for protection against the short circuit of an MOS-type power device comprises at least one secondary branch cirucit arranged in parallel with a main branch circuit which includes the power transistor. The secondary branch includes a control MOS transistor having the same characteristics as the power transistor under control and the ability to conduct a current equal to a fraction of that flowing through the power transistor. The gate of the control transistor is connected directly with that of the power transistor. The secondary branch also includes means sensitive to temperature which, in the case of a current flow corresponding to the short circuit current of the power transistor, act on the gate common to the control and to the power transistors so as to lower its voltage and thus limit the conduction of same.

Abstract: A neutral line circuit interrupter having a switch in the neutral voltage line to trigger the interrupter upon the occurrence of a predetermined event to disconnect the line voltage from the load. Both contacts of the switch are at the identical, neutral voltage level so that the switch is not subject to a high voltage and can be used in remote locations where the presence of a high voltage would be undesirable.