Abstract: A ground fault circuit interrupter (GFCI) with built in intelligence is described that includes circuitry to automatically indicate a device miswiring condition. When a GFCI is wired with its AC and LOAD terminals reversed, downstream devices are still protected in the event of a ground fault but the duplex receptacle on the GFCI itself is not. The invention incorporates miswiring sense circuitry that automatically triggers the generation of visual and audible alarms in the event a miswiring condition is sensed. The invention employs an alarm inhibiting technique that incorporates sense circuitry connected to the AC terminals on one side of the internal GFCI switches or relays and alarm generation circuitry connected to the LOAD terminals on the opposite side.

Abstract: An ESD protection structure for p-well technology using nMOS FETs that prevents the lock-on condition normally occurring after one FET of a multi finger structure snaps back. The multifinger structure is contained in a main p-well and channels ESDs of a first polarity from the contact pad to a metal conduit. A resistance is provided between the main p-well and the conduit. Further, the circuit channeling ESDs of a polarity opposite to the first polarity is contained in a second p-well that is distinct from the main p-well. An ESD event causes one of the fingers to snap back. Resulting drain current through that finger generates electron hole pairs in the main p-well by impact ionization. Thus generated holes, traveling to the conduit through the resistance, raise the voltage of the main p-well, and therefore shift the i-v characteristic curves of all the FETs to a point where they no longer exhibit a knee.

Abstract: An ESD protection circuit combines a split bipolar transistor with a transistor layout which exhibits very high tolerance to ESD events. The split bipolar transistor divides current among many segments and prevents the current hogging which often causes an ESD failure. Several splitting structures are disclosed, each combining a resistor in series with each segment to distribute current evenly. The transistor takes advantage of the snap-back effect to increase current carrying capacity. Layout positions metal contacts away from regions of highest energy dissipation. Layout also allows high currents to be dissipated through ESD protection structures and not through circuit devices such as output drivers or through parasitic bipolar transistors not designed for high current. Sharp changes in electron density are avoided by the use of high-diffusing phosphorus in N-regions implanted to both lightly and heavily doped levels. Critical corners are rounded rather than sharp.

Abstract: An electric energy storage and distribution system for a fluid-driven propeller, the propeller being connected to drive an AC generator, includes a planetary gear system by means of which rotation of the propeller is transferred to the AC generator motor, via a ring gear and a sun gear attached to a DC generator/motor, the DC generator/motor being connected to a battery. When the speed of the propeller is insufficient to drive the AC generator at a desired frequency and voltage, the DC motor is driven by the battery to either assist rotation of the propeller or the propeller can be braked such that the DC motor alone drives the AC generator. When an excess propeller speed is obtained, the propeller drives both the AC generator and the DC generator, the DC generator charging the battery. Conversely, when excess power is available through the power grid, the AC generator can be used as a motor to drive the DC generator via the ring gear, planetary gear, and sun gear to charge the battery.

Abstract: An apparatus for detecting differences between zero-sequence current caused by load unbalance and fault current caused by fallen distribution conductors. The apparatus makes it possible to readily check a high impedance fault. The apparatus includes analog-to-digital converters for converting analog A-, B-, C- and neutral phase current signals to digital data, respectively. The apparatus further includes a data processing system for computing even order power, rate of the even order to odd order power, and incremental variance of even order power. The apparatus analyzes the digital data and determines the fault when the computed information is compared with respective setting values and is greater than the setting values.

Abstract: A current limiting device using a superconductor limits a current flowing throu A c5 V pV:a current limiting coil, which mangetically couples to the superconductor. A control coil is provided to magnetically couple with the current limiting coil when the superconductor is switched to a normal conduction state. A variable control impedance is connected to the control coil to adjust a control current flowing through the control coil. The current limiting impedance value of the current limiting coil is adjusted by the value of the control impedance to obtain an adjustable value of the current flowing through the current limiting coil.

Abstract: An electrotechnical power supply system includes several power sources and interconnectable feeders, and an overall isolation monitor and at least one locator on each power source.All the overall isolations monitors and locators are connected together by a local data bus transmission network.A plurality of connecting circuit breakers are arranged between the power sources. A management unit is electrically connected to the transmission network for transmitting control signals to the overall isolation monitors, so as to switch some of the monitors to an inaction excluded mode, with the exception of a single one of them which operates as pilot in an active mode.

Abstract: Disclosed is a negative-sequence time-overcurrent relay for use in a polyphase synchronous rotary electric machine having a main-circuit breaker and an exciting circuit.

Abstract: A switch unit receive an AC signal and includes first and second push-button switches and at least one rectifying diode. Each of the first and second push-button switches is a 2-stage switch or a 3-stage switch. The first and second push-button switches and the at least one rectifying diode are configured such that the switch unit selectively generates any one of a non-signal, a positive half-wave rectified signal, a negative half-wave rectified signal and a full wave alternating signal to first and second outputs. The first and second outputs of the switch units are transmitted to an output unit by way of two transmission wires, respectively. The output unit discriminates the switching state of the first and second push-button switches based on the signal received from the switch unit via the two transmission wires.

Abstract: A circuit for protecting nonvolatile memories against loss of Vcc while Vpp is high. An NMOS gated by Vcc is connected, in series with a load element, between Vpp and ground. The node between the NMOS and the load element gates a PMOS which is interposed between Vpp and the memory. Thus when Vcc fails while Vpp is high, the NMOS will turn off, and the load element will pull up the gate of the PMOS to turn it off, interrupting the Vpp supply. This prevents spurious write or erase operations under these circumstances. The circuit can be designed to trigger at threshold voltages as low as V.sub.TN, and is thus particularly advantageous for operation with specified Vcc values of 3 Volts or less.

Abstract: A protection circuit includes a first controlled path for discharging negative ESD pulses introduced at a signal node. The first controlled path is from the signal node to V.sub.cc via the source and drain electrodes of a first transistor. The gate of the transistor is at a soft ground by connection of the gate through a resistor and an inverter to a fixed voltage supply potential (V.sub.cc). A second controlled path discharges positive ESD pulses via source and drain regions of serially connected second and third transistors to ground. The second transistor has a gate tied at V.sub.cc by means of a resistor and inverter to ground. The third transistor is at soft ground by means of a resistor and inverter to V.sub.cc. The third transistor is turned on by a positive voltage exceeding the threshold voltage of the third transistor, but the second transistor prevents damage to the third transistor by limiting the voltage applied to the third transistor.

Abstract: An exciter for an internal combustion engine igniter plug, comprises a continuous AC charging circuit and a discharge circuit. The discharge circuit is connectable to the plug and the charging circuit includes a transformer having a primary winding connectable to an AC power source and a secondary winding connected to the discharge circuit. The discharge circuit includes a storage capacitor connected to the transformer secondary winding such that current induced in the secondary charges the capacitor at a generally constant rate. A switching device is connected in series between the capacitor and the plug; and a trigger circuit triggers the switching device in response to charge on the capacitor; with the charging circuit and trigger circuit operating to maintain a generally constant spark rate. A current multiplier is also provided to substantially increase the peak currents delivered to the plug.

Abstract: A wire-less dart adapted to be projected by a gun and capable of applying an electrical pulse of sufficient energy to stun a target. The dart includes a photovoltaic cell responsive to a coherent electromagnetic energy source, such as a laser, for converting the beam energy to an electrical pulse. The dart also includes a pair of barbs extending from its distal end which penetrate the target's skin to a non-injurious depth. These barbs serve as electrodes and deliver the electrical pulse to the target. The projector, such as a gun, includes a pulsed laser light source which is aimed at the same location as the projector. Accordingly, the laser source focuses the pulsed laser energy source upon the dart PV cell. The projector includes a propellant sufficient to launch the dart, but with only enough kinetic energy such that the dart barbs penetrate the assailant's skin. The device has a long operating range.

Abstract: A DC electromagnet apparatus that can prevent an excessive making coil current caused by changes in a power supply voltage. The electromagnet has an operation coil, a switching device, and a current detecting resistor connected in series. A one-shot pulse generating circuit produces a one-shot pulse having a pulse width corresponding to the duration of the making coil current flowing through the operation coil to close the electromagnet. A Miller circuit generates, based on the one-shot pulse, a trapezoidal pulse having a predetermined rising rate, a predetermined peak value, and a pulse width substantially equal to that of the one-shot pulse. A comparator produces an ON control signal that controls the switching device in such a manner that the making coil current becomes proportional to the trapezoidal pulse.

Abstract: A switching device (2) comprises a plurality of switching means (4) connected in series by input conductor (12) to an input terminal (8). A plurality of respective load means (6) are connected between the switching means (4) and an output terminal (10). Each of the switching means (4) is adapted to selectively activate the respective load means (6) by connecting it to the input terminal (8) in response to a corresponding voltage level applied to the input terminal (8).

Abstract: An efficient fan drive circuit to drive a variable fan used in a power supply of a personal computer system. The fan drive circuit uses a diode to establish the minimum fan speed during operation in the normal temperature range. The bleeder resistor normally coupled between the fan and a negative output voltage is removed and replaced with a current source. The current source also serves to shut down the power supply if the fan is not operating properly or is not installed. A shut down circuit remains to shut down the power supply when excessive temperature occurs, or when the current source detects that the fan is malfunctioning or not installed.

Abstract: A relay control circuit in which a capacitor is used as a power source of a transistor which prohibits operation of the transistor which is operated by input by switch operation. If power is no longer supplied to the entire relay control circuit while the capacitor is discharging, switch input is prohibited.

Abstract: An anti-abuse circuit and method is described for shutting down a load wherein the load is connected to a controller having a predetermined range and demanding operation of the load through a relay until the predetermined temperature range is achieved. The anti-abuse circuit is positioned between the controller and the load. The anti-abuse circuit controls the relay when a demand signal is present indicating the operation of the load. The anti-abuse circuit energizing the relay during the predetermined time period and receipt of the regulated demand signal. The anti-abuse circuit de-energizing the relay when either the predetermined time period expires or the regulated demand signal stops.

Abstract: Alternating current provided at an angular frequency (.omega.) for powering an electromagnet force actuator having a leakage inductance (L.sub.1) whereby the alternating current is controlled by a voltage reference and a feedback signal indicative of the controlled current and amplified at a gain factor (K.sub.1) having a magnitude greater than or equal to the leakage inductance (L.sub.1) times the angular frequency (.omega.), whereby the electromagnet has a flat or positive spring rate.

Abstract: In a power receiving system, a network transformer, a protector breaker and a current detector are connected between the load side of each of a plurality of network lines and a network bus, a breaker is connected to the primary side of the network transformer, the current detector being operative to detect an accident current on the secondary side of the network transformer, and relays or an operation controller is provided which is responsive to the detection signal to open the breaker and protector breaker to switch off accident currents on the primary and secondary sides of the network transformer, whereby the protective range is so expanded as to cover a line section between the network transformer and the protector breaker and the scale of the overall power receiving system is reduced.