Abstract: An electric vehicle control device including a collector for extracting power from an overhead wire and a circuit breaker for breaking the power. The power includes first AC power in AC power source zone and first DC power in DC power source zone. The device also includes a changeover device for changing over the power to apply the first AC power to an AC side or the first DC power to a DC side, a transformer connected to the AC side of the changeover device for transforming the first AC power into second AC power, a first opening/closing device, a power converter for converting the second AC power to second DC power and an inverter for converting the second DC power into third AC power. The third AC power is supplied to drive an electric motor. The device further includes a second opening/closing device, a filter inductor and a filter capacitor connected between positive and negative terminals of the DC input side of the inverter.

Abstract: The power supply, useful with an electromagnetic force apparatus such as a riveter or a bolt inserter, includes two capacitor banks which are charged through charging doubler modules. Each charging doubler module includes an AC capacitor which is responsive to a power source. The AC capacitor is connected to a node point between two diode elements, which are connected in series across the capacitor bank. An analog-to-digital converter converts the voltage on the capacitor bank to a digital voltage for comparison with a selected digital charge voltage in a controller. The selected digital charge voltage may vary over time by means of a compensating algorithm. A ground fault indicator using a biasing voltage is connected between a selected electrical circuit portion of the force apparatus and earth ground. A gas discharge tube in combination with a current sensing element is connected to the capacitor banks to determine a possible over-voltage condition.

Abstract: A current throttle resistor external to a contactor device protects an electrical power distribution circuit coupling a load to a power line. The contactor has electrical switching contacts in series with the load and the line, and for example, an electromagnetically controllable switch for opening the contacts. A current sensor is coupled to the controllable switch for opening of the contacts upon occurrence of a high current fault in the power distribution circuit exceeding a predetermined threshold. A resistive element in series with the power distribution circuit between the line and the load, provides a voltage drop for limiting current during the high current fault. The resistive element can be a nichrome strip or similar positive temperature coefficient resistance having a low cool resistance, and is thermally isolated from the controllable switch by mounting in a resistor housing external to the contactor.

Abstract: The coder generates code information A.sub.1 -A.sub.N, each representing one of Q quantization points of an input signal, where Q is an integer equal to or less than 2.sup.x and X is a positive number, synthesizes the code information A.sub.1 -A.sub.N into a code H through an operation:H=A.sub.1 Q.sup.N-1 +A.sub.2 Q.sup.N-2 + . . . +A.sub.N-1 Q+A.sub.N,and outputs the code H. The decoder inputs the code H, separates the code H into code information A.sub.1 -A.sub.N through operations with decimal fractions of quotients truncated:A.sub.1 =H/Q.sup.N-1A.sub.2 =(H-A.sub.1 Q.sup.N-1)/Q.sup.N-2A.sub.N-1 =(H-A.sub.1 Q.sup.N-1 -A.sub.2 Q.sup.N-2 - . . . -A.sub.N-2 Q.sup.2)/QA.sub.N =H-A.sub.1 Q.sup.N-1 -A.sub.2 Q.sup.N-2 - . . . -A.sub.N-2 Q.sup.2 -A.sub.N-1 Q,and reproduces an output signal based upon the thus-separated code information A.sub.1 -A.sub.N.

Abstract: A power supply polarity reversal protection device includes a voltage controlled switching device, e.g. an N-channel MOSFET connected between the power supply output (e.g. a positive supply voltage) and the circuit to be powered by the supply, i.e. the load. A diode, preferably the parasitic diode inherent in the MOSFET between the drain and source, is arranged so that when the positive supply terminal is connected to the transistor, the diode is forward biased and will allow a diode current to flow. A sensing means generates a control terminal voltage in response to the diode current flow. This control terminal voltage is applied to the switching means control gate and is sufficient to cause full conduction through the switching means. If, instead, a negative supply voltage is connected to the transistor, the diode will be reverse biased and no current will flow.

Abstract: A method and apparatus for avoidance of power-up current surge upon activation of a current supply device under inductive effect. An alternating-current switch is connected in series with the current supply device and a phase cut-in circuit is provided for enabling adjustable connection of the current supply device with the mains alternating voltage starting with the instant of powering up with equal-size unipolar phase segments. A switching unit is provided for activation of the phase cut-in circuit so that a predetermined number of the equal-size unipolar segments can be produced. An oppositely poled half wave which follows in time immediately is switched with an ignition signal of 170 to 180 degrees. In the phase cut-in circuit, respectively, an ignition signal is produced at the predetermined phase cut-in angle in the half waves following this half wave.

Abstract: A device for protecting battery-powered semiconductor devices and the like against a reverse battery condition. During normal operation a charge pump charges the gate of a power MOSFET, turning the MOSFET on and providing a low-resistance power supply path from the battery to the load. If the battery is reversed, a depletion mode device shorts the gate and source of the MOSFET, turning it off and disconnecting the load from the battery.

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 high power d.c. breaker for connection into a d.c. carrying high-voltage line (L), has two normally closed and electrically series-connected mechanical breaks (BSI, BSII) adapted to be traversed by the line current (I) and to be opened for breaking the current. A capacitor (CB) is connected in parallel with the series connection of the breaks. A semiconductor member (HO) is connected in parallel with one of the breaks (BSI). Upon opening the breaks, a control member (SO) controls the semiconductor member such that a zero crossing of the current through the second break (BSII) is obtained, whereby the line current (I) is commutated over to the capacitor. (FIG.

Abstract: Apparatus and method are supplied for an electrical power substation used to interconnect an input three-phase power line to one or more poly-phase output distribution power lines. The teaching of the subject application shows that parasitic losses in prior art substation wiring that uses coaxial cables to conduct power into and out of the substation can be reduced by using an individual grounding rod for each outer conductor instead of following conventional practice and connecting all three conductors together at a common grounding rod. Moreover, if the three input coaxial cables to the distribution substation or the three output coaxial cables from the substation have the current in a center conductor precisely matched to the return current in the associated outer conductor, there will be neither an electric potential gradient nor a magnetic intensity outside of the transmission lines.

Abstract: An overcurrent protection device for a motor M with an overheat prevention function having a housing 10 with fixed contacts 16, 18 and movable contacts 24, 26. A first snap acting bimetallic element 20 in the device is responsive to heat from overcurrent conditions and a second snap acting bimetallic element 40 is responsive to heat from the temperature for the motor M. The movable contacts 24, 26 are controlled by the first bimetallic element to cause engagement or nonengagement with the stationary contacts 16,18. Coupling members 42, 44 contained in the housing engage both bimetallic elements 20, 40 and allow the first overcurrent bimetallic element 20 to snap independently of the second bimetallic element 40 while providing for snap action of the second bimetallic element 40 to also cause the first bimetallic 20 to snap.

Abstract: A circuit protects pads of an integrated circuit having a plurality of power supply sources against electrostatic overvoltages. Each power supply is connected between a high voltage pad and a low voltage pad. Each pad of the circuit, as well as each power supply pad, is connected to the anode of a first diode having its cathode connected to a first conductive bus, and to the cathode of a second diode having its anode connected to a second conductive bus. A unidirectional clipping device is connected by its cathode to the first bus and by its anode to the second bus.

Abstract: A thermal protector for a hermetic electrically-driven compressor including a hermetically sealed housing in which a power-supply terminal, an electric motor and a compressor are enclosed with a predetermined amount of refrigerant gas is disclosed. The thermal protector includes a thermally responsive switch having first and second lead terminal pins for securing first and second connecting terminals respectively and a holder formed from an electrically insulating material and including first, second and third cavities. Each of the first and second cavities has an opening in its one side. The first cavity accommodates the thermally responsive switch while the second cavity accommodates a secured portion between the lead terminal and the connecting terminal with a hardenable electrically insulating filler filling up the second cavity. Alternatively, the second connecting terminal is secured to a wall of the holder by an insert molding so as to extend through the wall, instead of use of the filler.

Abstract: In an integrated circuit with protection against electrostatic discharges, there is provided a first voltage limiter connected between a pad to be protected and a ground bus. This first limiter is placed the peripheral part of the integrated circuit in the vicinity of the pad And there is provided a second voltage limiter directly connected to a circuit element to be protected. This second limiter is placed in the useful part of the integrated circuit and not in the peripheral part. Thus, the risks related to the resistors of the ground bus, crossed by high electrostatic discharge currents, are avoided.

Abstract: In portable terminal units each of which has a rechargeable battery and a data processing section, one terminal is used as both a terminal for charging the rechargeable battery and a terminal for connecting a data processing unit to an external data processing unit. First protective circuitry protects the data processing unit from a battery charging current and second protective circuitry eliminates loading of the rechargeable battery due to a data voltage and protects the external data processing unit from charging current for the chargeable battery.

Abstract: A transistor in an output stage has an emitter connected to a supply rail and a collector connected to an output node. The transistor is protected against the effects of accidental shortcircuiting of the output node of the output stage with a positive pole of a battery while the circuit is unpowered, by a protection transistor of the same type as the transistor to be protected. The protection transistor has an emitter connected to the base of the output transistor, a collector connected to the output node of the output stage, and a base connected through a biasing resistance to the supply rail on the output stage. The protection transistor and an interdigitated structure of the transistor may be formed within the same pocket, thus reducing the required area.

Abstract: A combined electrical plug and circuit breaker that interrupts current when excessive current flows. A housing receives a body portion with extending blades. A bi-metallic strip opens silver contacts when an overload occurs. A rod member can reset the contacts when the overload problem is solved.

Abstract: A low voltage power supply and distribution center comprises a housing (12) having three internal compartments including: a high voltage compartment (17), a low voltage distribution compartment (19), and a transformer compartment (21). The housing (12) is designed for surface or recessed mounting on or in a wall or ceiling. For recessed mounting, with the housing (12) surrounded with 20 cm (8 inches) of insulation, the maximum surface temperature of the housing is less than 90.degree. C. The three compartments (17,19,21) are formed by a removable power tray (15) having a torodial transformer (132) mounted thereon. The low voltage compartment (19) comprises a fuse panel (150) for mounting a plurality of plug-in fuses (153) from which the low voltage power is distributed. The high voltage compartment (17) comprises a switch or a dimmer (131) in a high voltage line between the transformer (132) and the incoming high voltage line, or the dimmer or switch may be remotely installed on a wall.

Abstract: A method and circuit is provided which controls and monitors a load through a single I/O pin of a microprocessor. A predriver circuit including a level shifter responds to a driver control signal from the microprocessor to control energization of a power driver connected in a load circuit. The predriver circuit also includes a monitor stage for detecting fault conditions of the load circuit. The output of the monitor stage is connected with the I/O pin which is configured as either an input or an output pin under microprocessor program control.

Abstract: An electrical service installation comprises a plurality of circuit breakers protecting against overcurrent hazards in branch load circuits. An acceleration, bypass circuit is provided for each circuit breaker. Current flow through each of the bypass circuits is controlled by a normally non-conductive SCR. Current flow to each branch circuit passes through a sensing resistor that is connected across the gate and cathode of the associated SCR. When the voltage drop across the sensing resistor reflects a current level indicative of an "arc short circuit", the SCR is triggered to a conductive state. Current then flows through the bypass circuit increasing current flow through the associated circuit breaker, to thereby provide a substantially increased current magnitude for magnetically tripping the circuit breaker. Circuit breakers are thus tripped to provide protection against the hazards of "arc short circuit" currents that do not have a magnitude sufficient to initiate magnetic tripping.