Abstract: An electrical receptacle having front and rear casings forming an enclosed housing for a printed circuit board carrying contacts into which the blades of a plug connected to the receptacle are inserted. The housing includes portions cooperatively placed with respect to the circuit board to provide underlying support for the contacts, as well as to assist in positioning the circuit board relative to the housing. The circuit components carried by the circuit board include three varistor devices for suppressing high transient voltages and the housing includes internal walls providing spaced cavities to receive the respective varistor devices. Another aspect concerns a one-piece mounting strap positioned entirely exteriorly of the receptacle housing and connected thereto by cooperative engagement portions on the strap and the housing, requiring no screws, rivets or other fastening devices.

Abstract: An organo-platinum complex of the formula ##STR1## wherein X and Y have the same meaning of a halogen, oxyanion or carboxylate, respectively or X is an oxyanion or dicarboxylate together with Y, and L.sub.1 and L.sub.2 are bonded together to form one of silicon containing diamine compounds selected from the group consisting of ##STR2## in which R.sub.1, R.sub.2 and R.sub.3 are a lower alkyl or phenyl, respectively, and n is an integer of 0 or 1,and use of the complex for an anti-tumor composition.

Abstract: In an automatic power turn-off apparatus, a signal for turning off power supply is outputted from a timer IC when time set by a power-off time setting key arrives, whereby the power supply of an associated copying apparatus is turned off. In the turn-off period, if an MPU determines that the copying apparatus is in trouble, the turn-off of the power supply is cancelled and the occurrence of the trouble in the copying apparatus is displayed in a display device to notify the user of the trouble.

Abstract: An output transistor (T.sub.1) is to be protected from damage due to excessive currents. This transistor supplies a current (I.sub.o) to a load (3) and is driven by a driver transistor (T.sub.2). The base-emitter junction of a current-sensing trnsistor (T.sub.3) is connected in parallel with that of the output transistor (T.sub.1). The collector current of transistor (T.sub.3) is a measure of the current (I.sub.o) of the output transistor (T.sub.1). A current generator (5) supplying a reference current (I.sub.ref) is coupled to the collector of the current-sensing transistor (T.sub.3). If the collector current of the current-sensing transistor exceeds the reference current (I.sub.ref) the protection circuit is activated so that the driver transistor is bottomed via an emitter-follower (T.sub.4). The base current of transistor T.sub.1 is thereby limited. Thus, the output current of the output transistor is limited to a maximum value which is substantially equal to the product of the reference current (I.sub.

Abstract: A surge suppressor comprises a first series circuit having a first inductance and a first alternating voltage limiter, including at least a first capacitance and a bidirectionally conductive rectifying circuit for charging the first capacitance, coupled between first and second input terminals for limiting surge currents and voltage excursions coupled to first and second load output terminals. The first alternating voltage limiter further comprises a sensing circuit for sensing at least one of the charging current supplied to and the voltage developed across the first capacitance. An auxiliary energy storage circuit and a normally open switching device responsive to the sensing circuit are provided for coupling the auxiliary energy storage circuit across the first capacitance during high energy surge conditions.

Abstract: A signal conversion circuit converts variations in resistance into an electrical signal. The conversion circuit comprises both a bridge circuit and a single operational amplifier with a capacitor between them to store voltage samples produced by an unbalancing of the bridge. The bridge circuit has a detector element such as a strain gauge for providing a resistance variation. A capacitor is connected through switches to both the bridge circuit and signal operational amplifier. The switches operate in a sequence whereby the operational amplifier is disconnected from the capacitor during the storage of the sample and the bridge is disconnected from the capacitor during intervals while the charged capacitor is connected to the amplifer.

Abstract: a protective relay for detecting faults in electrical power distribution system generates a signal .DELTA.i(t) which is substantially equal to the magnitude of the power distribution system current i measured at a first time subtracted from the magnitude of the power distribution system current i measured at a second time, the second time occurring later than the first time. The signal .DELTA.i(t) is utilized to generate measurement of the distance of a fault to the relay and is also utilized to generate operate signals if the fault occurs within the zone protected by the relay.

Abstract: In a ground circuit apparatus for electronic equipment according to this invention, a motor driving circuit group constituted of a drum motor, a loading motor and a capstan motor is connected with a DC power source through a power source line and a ground line to have power supplied therefrom. A signal processing circuit group constituted of a camera circuit, a logic circuit, servo circuit, video circuit and an audio circuit as well as an electronic view finder is connected with the DC power source through the power line and a ground line. A video circuit of the signal processing circuit group is connected through a ground line to a chassis which serves as a reference potential point. In addition, two diodes connected in parallel and directed in mutually opposite directions to have opposite polarities and a ground line are connected between the electronic view finder and the chassis.

Abstract: A solid state switching device allows independent control of the latching and holding currents, and has particular application to telephone systems. The holding current may be set at a high level so as to return the switching device to the off-state without a large reduction in the current to the circuit embodying the switching device, whereas the latching current may be set at a low level to reduce the heat dissipation in the device just prior to the transition from the latching state to the holding state. The device, which may be implemented in either linear technology or with discrete components, is a thyristor structure defined by npn and pnp bipolar transistor devices each having its base connected to the collector of the other. Each transistor device has a resistance between its base and emitter, and in the case of at least one of the transistor devices that resistance varies with the voltage on the collector of the associated transistor device.

Abstract: A protection circuit for a battery charger for safely charging a battery from a remote electrical power supply is disclosed. The protection circuit includes a power control means responsive to input from the remote power supply; an overload sensing means responsive to the power control means and to the negative polarity of the battery; a main switching means responsive to the overload sensing means and to the power control means wherein the main switching means controllably limits current output in the presence of a slight overload condition, and deactuates the battery charger in the presence of a large overload condition.

Abstract: A universal programmable logic control device for monitoring the current of a circuit and for signalling a circuit control device, such programmable logic control device including; electrical power circuitry for activating the circuit control device; electrical circuitry for monitoring the current in the electrical circuit, such electrical circuitry including, adjustable electrical signal input circuitry to match the programmable logic control device to the electrical current in the circuit, adjustable pick-up circuitry for adjusting the level of the current monitored in the electrical circuit, adjustable time circuitry for adjusting the time duration of the selected level of electrical current, so as to command the electrical power circuitry to activate the control device when the electrical current in the electrical circuit reaches the selected level and time duration; and a zenor diode in reverse mode for controlling the level of voltage applied to the adjustable pick-up circuitry and time circuitry substa

Abstract: A protective circuit capable of remotely switching power to a load on and off and including an electrothermal sensor system having a heating element of predetermined resistance in series with the load and source of power whereby the temperature of the heating element is monitored relative to ambient temperature to determine current flow in the heater. The electrothermal sensor, according to one embodiment, includes a ceramic substrate having the heater formed thereon with a first deposited heat monitoring element thereon for monitoring the temperature of the heater and a second heat monitoring element thereon for monitoring the ambient temperature of the substrate remote from the heater. The electrothermal sensor, according to a second embodiment, includes a layer of electrically conductive material, a backing layer thereon of electrically insulating material, a grid on the backing layer of thermoresponsive material to form RTDs and a second layer of electrically insulating material over said grid.

Abstract: Electrical transient surge protection plus safeguarding of surge-protection apparatus against failure at high temperature. Thermally sensitive fusible devices are used in conjunction with voltage-limiting devices, specifically varistors, so as to protect watt-hour meters and downstream loads from electrical surges, and to safeguard such varistors from overheating and possibly failing. Such apparatus may be located in such diverse places as a power line weatherhead, a watt-hour meter base, an adapter between a meter base and its normal mounting socket, or a circuit-breaker panel downstream of the meter and upstream of electrical loads metered thereby.

Abstract: In power switches, conductive coupling of the control signal inputs to the power switching stage, and to the load to be switched, can result in impairment of control function. Moveover these power switches known in the art, have the disadvantage that the drive circuit and power switching stage must lie at the same potential. An improved self protecting power switch includes a first drive unit and a second drive circuit that are connected together via a pulse transformer. The first drive unit generates successive pulse trains in response to a control signal. A second drive unit regenerates square wave signals for the control of the power switching stage.

Abstract: Differentially-connected pairs of JFETs on an IC chip are protected from ESD events by connecting respective discharge control resistors to the drains of the JFETs in such a manner as to be in series with any flow of current through either JFET.

Abstract: A protection circuit for a battery feed circuit used in a switching system. The protection circuit is comprised of: a supervising circuit for detecting an abnormal current flowing through a battery feed resistor; and a voltage limiting circuit for clamping a voltage across the battery feed resistor when the abnormal current is detected. Further, a control circuit is employed for stopping an operational amplifier, which is a component of a conventional battery feed circuit, when the abnormal current is detected.

Abstract: A power bus fault detector for detecting faults in a predefined portion of an electrical power bus having at least one phase. Power feed lines are coupled to the predefined portion of the power bus by circuit breakers. Current transformers are used to detect the current flowing through each phase of each power feed line which is coupled to the predefined portion of the power bus. A summer generates a current differential signal for each phase that is equal to the sum of the currents detected by the current transformers. A fault detector generates a trip signal which causes the feed line circuit breakers to disconnect the feed lines from the power bus when a fault is detected in the predefined portion of the power bus. The fault detector includes a detector which detects when the current differential signal in any of the power bus's phases is substantially nonsinusoidal in shape.

Abstract: A driving apparatus for a DC circuit breaker of reverse current insertion type. The driving apparatus includes a magnetic repulsive coil for instantaneously driving a movable electrode of a vacuum valve directly in an opening direction, and a first coil of capacitor energization type and a second coil for voltage tripping purposes as trip coils for an operating mechanism connected to the movable electrode through a contact spring whereby the magnetic repulsive coil and the first trip coil are respectively energized by capacitors in the case of tripping under faulty conditions and only the second trip coil is energized in the case of tripping under other conditions than faulty conditions.

Abstract: A method and apparatus for controlling power to a preciptator 27. After each spark the power to the precipitator is reduced to zero, increased along a fast ramp 15 for a fixed period of time and then increased along a slow ramp 17 until a spark occurs. The fast and slow ramp data is computed and stored (memory 48) and then retrieved after each spark. The data retrieved is the data corresponding to the firing angle at the last spark. Apparatus is provided (selector 51 and memory 52) for dividing (frequency divider 45) the retrieved slow ramp data by a number to select the number of sparks per minute. Also the AC current and the AC voltage in the power to the precipitator are detected and the RMS values are obtained (32 and 34) and compared 35 and if the difference is above a predetermined value the power is disconnected (relay 36 and contacts 23 and 24).

Abstract: A device for protecting an integrated circuit against overload and short circuit currents. The integrated circuit functions such that it is alternatingly switched to an ON or an OFF state, and when in the ON state a supply current (I.sub.M) is amplified by a Darlington-connected transistor step (Q.sub.20,Q.sub.21) and is supplied to the output (OUT) of the circuit across a load resistor (R.sub.LOAD). For an OFF state of the integrated circuit no current is led to the output (OUT). A protective circuit (S) comprising a detection resistor (R.sub.SENSE) is connected in series with said load resistance (R.sub.LOAD). The protective circuit also includes a differential step (D) for sensing a voltaqge (V.sub.SENSE) across the detection resistor (R hd SENSE) and a thyristor (T). Short circuit or overload on the output (OUT) causes an overcurrent to pass through said transistor step (Q.sub.20,Q.sub.21) and through the detection resistor. The increasing voltage (V.sub.