Abstract: A simple, inexpensive automatic apparatus for unplugging electrical and electronic equipment from electrical circuits such as power, cable television and telephone circuits when an electrical storm is detected in the vicinity of the device by monitoring conditions that typically change near electric storms and, when one or more indicia of a storm are noted, physically disconnecting the device from the circuit(s) so that substantial insulation is interposed between the device and the circuit(s). In some configurations, re-connection of the electrical or electronic equipment automatically occurs after an electrical storm has passed.

Abstract: A commutation type DC breaker having a commutation circuit electrically connected in parallel to a main contact. The main contact is connected between a DC power supply and a load. The commutation circuit is a series circuit of a commutation capacitor, a reactor and a commutation switch, with an energy absorption device electrically connected in parallel to the main contact. A switch or a breaker for preventing the flow of commutation current from the commutation circuit to the load in a non-load opening mode is connected between an electrical connection point (P), of the main contact and the commutation circuit, and the load and is opened substantially simultaneously with the opening of the main contact, or before the closure of the commutation switch. In this manner, the safety on the load in the non-load opening mode is enhanced.

Abstract: A circuit protection device for use with an electrical unit comprises driver circuitry connected to the electrical unit and connecting means electrically connecting the device to the electrical unit to provide a voltage signal indicative of a voltage associated with the electrical unit. A voltage detector is connected to the connecting means and receives the voltage signal, and provides a conditioned voltage signal output representative of the voltage signal. An analog-to-digital converter receives the conditioned voltage signal output and converts the conditioned voltage signal output to a digital value. A digital processing device receives the digital value from the analog-to-digital converter and provides an output signal to the driver circuitry to turn off power to the primary if an error is detected.

Abstract: A power source circuit is provided having a high frequency transformer 16, a switching control circuit 15 connected with the primary winding of the transformer 16, rectifier circuits 17, 18 and 20 connected with the secondary winding of the transformer 16 for outputting a D.C. voltage to an external circuit, an alarm detection circuit 25, an excess current detection circuit 26, and an excess current detection delay circuit 28. When the alarm detection circuit 25 detects an excess current in supplying power source, the power source supply is suspended by turning off the output of the switching control circuit 15 after the lapse of the preset time. When the excess current flows after the lapse of the initial preset time t.sub.s from turning on the power source, the excess current detection circuit 26 detects it so that the output of the switching control circuit 15 is turned off.

Abstract: In order to guarantee that the gas atmosphere of the structure of an encapsulated spark gap (9) is reliably protected from the effect of moisture, two flat discharge surfaces of two dish-type electrodes (1,6), each designed with a collar-shaped rim (2), abut on both sides of a thin insulating layer (4) having punched holes. A tubular glass insulator (3) is sealed on the front side into the collar-shaped rims of the two electrodes. During the course of their manufacturing, the electrodes are placed with their collar-shaped rim on the front sides of the glass insulator, are inductively heated and, under the action of an axially directed pressing force, are driven toward one another and pressed against the insulating layer. A spark gap of this type can be used as a secondary discharge gap for triple-electrode arresters.

Abstract: A circuit for connecting the power supply output of a computer to ground when the system is shut down to counter adverse effects of backfeed voltage which includes a MOSFET between the power supply output and ground. In one embodiment the MOSFET is switched on by a signal that deactivates the system power supply. In an alternative embodiment, two MOSFETs are used. The first MOSFET is controlled directly by the power supply output and shorts the second MOSFET's gate to ground when the power supply output generates a significant voltage. If the second MOSFET's gate is grounded, the MOSFET deactivates and opens a circuit between the power supply output and ground. When the power supply is turned off, the second MOSFET activates and grounds the power supply output. A resistor between the power supply output and ground allows the power supply to generate five volts when the system is power cycled and deactivate the second MOSFET.

Abstract: A discharge relay electrode is located between terminal electrodes of a gap-type surge absorber. In a microgap embodiment of the invention, a conducting film on a surface of an insulating tube is split by two circumferential gaps spaced apart longitudinally. The discharge relay electrode is positioned between the two gaps. In a gap type surge absorber, the discharge relay electrode is positioned within the insulating tube midway between the end electrodes, substantially filling the cross section of the tube, and dividing the interior of the tube into a plurality of chambers. For both types of surge absorbers, the discharge relay electrode is effective to relay discharge between the terminal electrodes.

Abstract: A solid state power controller for switching power on and off to an electrical load which also serves as a circuit protection device protecting the load and/or the wire connected between the load output terminal of the controller and ground from thermal damage due to current overload is shown. When a current overload exists the controller interrupts current to the load in a time inversely proportional to the square of the magnitude of the overload as shown in a trip time vs load current curve. The controller also limits the load current to a selected maximum level by controlling the drain-source resistance of power MOSFETs used for switching the power. A secondary interrupt is provided in the event that the junction temperature of the MOSFETs has risen a selected maximum level. A thermal memory feature is included for both interrupt signals. The controller is controlled by a single on/off input line and provides both a status and trip output line to indicate its state.

Abstract: A portable power unit has a protective circuit for cutting off an output current from the power unit when the power unit is in an overload state. An amount of the output current is detected. An output voltage from the power unit is reduced when the amount of the output current detected reaches a first threshold value, thereby preventing the protective circuit from undesirably operating for one power unit when it is connected for another for parallel operation. When the amount of the output current decreases to a second threshold value which is smaller than the first threshold value, with the power unit being in a state in which the output voltage is reduced, the voltage-reducing operation is canceled.

Abstract: An apparatus for operating discharge lamps with a stable electric current supply and minimal dimensional area requirements. The apparatus includes an input power source coupled across a capacitor, establishing a first loop circuit. A discharge lamp may also be connected across the capacitor, thereby forming a second loop circuit. A first switch repeatedly turns ON and OFF, making and breaking the first loop circuit at a first frequency, and thereby charges the capacitor. A second switch repeatedly turns ON and OFF, making and breaking the second loop circuit at a second frequency, and thereby discharges the capacitor through the discharge lamp. A control mechanism controls the first and second switches for supplying a predetermined current to the discharge lamp for flickerless operation.

Abstract: A circuit for improving the short circuit withstand capability of an IGBT. The circuit utilizes a MOSFET which, when turned on, reduces the voltage applied to the gate of the IGBT during a short circuit condition, thereby lowering the short circuit current passing through the IGBT. A Zener diode is coupled between the MOSFET and the gate of the IGBT to clamp the voltage of the gate of the IGBT to a predetermined voltage when the MOS transistor is turned on during a short circuit condition. The circuit turns the MOSFET on when the voltage at the collector of the IGBT rises during a short circuit condition. If tile fault is of a short, transient type, the circuit advantageously restores the normal gate voltage. The circuit draws a small current from the gate driver and requires no separate DC source, making it feasible to insert the circuit in IGBT modules or connect the circuit as an interface between the gate driver and the gate.

Abstract: A load drive apparatus is used in a vehicle direction indicating apparatus operable free from overcurrents and overvoltage. The load drive apparatus includes: a charging/recharging capacitor; a charging/recharging circuit for charging/recharging the capacitor at a preselected time constant in such a manner that a voltage across the capacitor is varied between a preset upper limit voltage and a preset lower limit voltage; a drive circuit for turning ON a power transistor series-connected to a current path employed to supply a current from a DC power source to a load, thereby driving the load when the charging/discharging circuit causes the capacitor to be charged, or the voltage across the capacitor is higher than, or equal to a predetermined voltage defined between the upper limit voltage and the lower limit voltage; overcurrent judging means for judging whether or not a voltage across terminals of the power transistor connected to the above-described current path exceed an overcurrent judging voltage.

Abstract: An apparatus for driving an expansion pole such as an expansion corner rod of an automobile including a motor for extending and shrinking said expansion pole, a main switch provided within a room of the automobile, and an auxiliary switch provided on the automobile at such a position that the auxiliary switch can be actuated from an outside of the automobile. When the auxiliary switch is actuated from the outside of the automobile, the motor is driven in a reverse direction to shrink the expansion pole. Therefore, the expansion pole can be shrunk without actuating the main switch provided within the room of the automobile. The auxiliary switch may be arranged within the expansion pole such that the auxiliary switch is actuated when the expansion pole is pushed down, pulled up or tilted.

Abstract: A starting apparatus is provided to start at least a two passenger protecting apparatus. In the starting apparatus, an auxiliary power supply has a capacitor supplied by a power source which is mounted to a vehicle, and is independently provided for each passenger protecting apparatus. Further, an acceleration switch serves to feed current from the auxiliary power supply to a squib for starting the passenger protecting apparatus when a vehicle acceleration exceeds a predetermined acceleration. The acceleration switch is provided for only one squib, and make and break of this switch is detected. If the switch is closed, switches corresponding to other squibs are turned ON so that current is fed to the squibs from each auxiliary power supply.

Abstract: A solid state relay comprising a pair of SCRs connected in inverse parallel relationship across a pair of output terminals adapted to be connected in series with a source of AC power and a load, each SCR having an anode connected to one of the pair of output terminals, a cathode connected to another of the pair of output terminals, and a gate terminal; a pair of MOSFETs connected as a bidirectional switch for providing a single current path connecting the gate terminals of each of the pair of SCRs, the bidirectional switch allowing current application to the gate terminals without generating switching noise; a pair of diodes allowing current to transfer in one direction from each of the output terminals to each of the gate terminals of the SCRs; a source of optically coupled input signals which are applied to rapidly enable the bidirectional switch to provide a current path to the gate terminals of the SCRs and to maintain the bidirectional switch in the on condition as long as an input signal is furnished by

Abstract: A dual path static control garment is formed of a garment material having a continuous grid of conductive fibers throughout the body section and sleeves. One elastic wrist hugging cuff is formed of an electrically conductive material and thereby connects one wrist of the wearer, through the garment itself, to a first grounding terminal secured to a body section of the garment. A second and independent grounding path is provided from the second cuff to a second grounding terminal on the body section. The second path is provided by a cuff assembly having an inner conductive wrist hugging cuff and an outer nonconductive cuff connected to the garment sleeve. A conductive ribbon encased in an insulating sheath electrically interconnects the inner conductive cuff to the second grounding terminal and is insulated from the garment and its sleeves to provide the second independent grounding path.

Abstract: An hydroelectric power plant is disclosed which comprises several combination turbine/generators which are suspended into an ocean current from a submerged tension leg type platform. Each of the turbine/generators are independently positionable horizontally, vertically and azimuthally to take the best advantage of the ocean current at any given time for generating electricity.

Abstract: An isolator surge protector for use with corrosion protection systems which are an inherent part of or coupled to an electrical power system, for power transformers, and for DC transmission systems, where it is necessary to present a high impedance to DC and a low impedance to AC up to a predetermined voltage level. Anti-paralleled thyristors in the isolator surge protector turn on during power surges. A bypass circuit insures turn off of the thyristors after a triggering event such as lightning or a 60 Hz surge has ended. The bypass circuit shunts DC bias currents, such as that which may be provided by a DC bias voltage source for cathodic protection, from the thyristors to ensure that the voltage across each thyristor falls below its holding voltage or current, and thus prevents the thyristor from being stuck in a continuous conduction mode. Power to operate the bypass circuit may be tapped from the surge which caused the thyristor to trigger so that the bypass circuit operates autonomously.

Abstract: A UPS device adapted for parallel connection to a load along with one or more other UPS devices, having circuitry for sharing of the load, including load harmonics. A feedback network has an error signal circuit which generates an error signal representative of the difference between the actual current provided by the device and the designated share of current it should provide. The error signal is transformed by a value representative of the effective output impedance of the UPS inverter, whereby the inverter is controlled to share the fundamental of the load current as well as the harmonics.

Abstract: A firing controlled scheme including a method and apparatus for vernier operation of a shunt-connected thyristor-controlled capacitor (STCC) uses phase controlled firing of the thyristors based on monitored line voltage, monitored thyristor current, and a thyristor current command to vary the effective reactance of the capacitor. The STCC includes a capacitor and surge inductor connected in shunt across a power transmission line via a thyristor switch. A vernier controller predicts an upcoming firing angle based on the above parameters and switches the thyristor circuit to partially conduct pulses of thyristor current at different amplitude levels depending upon the commanded firing angle. By varying the firing angle, variable inductive and capacitive reactive power can be selectively delivered to the transmission line.