Abstract: Apparatus and method for controlling current flow through a magnetic coil actuator of a solenoid valve. The current through the magnetic coil is measured by sensing the voltage drop across a precision resistor in series with the coil. The apparatus includes a power switch for alternately switching the coil on and off. A flyback diode is coupled in parallel with the coil for operation during coil shut-off. A first voltage sensor continuously measures the combined voltage drop across the coil and the power switch. A second sensor, coupled across the precision resistor, samples the current flowing through the coil. The samplings occur synchronously with coil turn-on, and are delayed by a predetermined time delay which is long enough to allow the current flowing through the coil to reach steady state before the current is sampled. Circuitry is provided for employing the sensed voltage signal and current samplings to produce a signal whose value is a function of the resistive component of coil impedance.

Abstract: AS uninterruptible power supply (UPS) is disclosed in which AC line power is used to charge back-up battery and to operate a load during a stand-by mode of operation of the UPS. In the back-up mode of operation when AC line power is not available, the battery is used to supply power to the load. The UPS is implemented with only one inexpensive high frequency transformer and a single bi-directional power converter. Thus, the UPS of the present invention is lower in cost and complexity than such UPSs known in the prior art.

Abstract: Method for managing electric power in a network (R) to which are connected, on the one hand, appliances capable of 2-way communication with each other, each appliance consisting of a power subassembly and a control subassembly and, on the other hand, a so-called power manager unit designed to manage load shedding and reconnection functions exclusively affecting the said power subassemblies of each appliance with each disconnectable appliance being disconnected a priori.Any request for significant electric power made by a disconnected appliance results in a transaction between the said appliance and the power manager during which the said requesting disconnected appliances supplies the said power manager with information of a quantitative and qualitative nature concerning the power requested and on completion of which the said power manager authorizes or does not authorize reconnection of the power subassembly of the said requesting appliance.

Abstract: An information handling system is described having a power supply (16) having a switching circuit (24) that switches a plurality of energy sources (20) and (22) between series and parallel couplings. Associated with the switching circuit (24) is a voltage level detecting circuit (18) for monitoring the voltage level of the energy sources (20) and (22). A processor (12) for controlling the information handling system (10) responds to the voltage level detecting circuit (18) and in the event of a low voltage condition, the processor (12) activates the switching circuit (24) to switch the energy sources (20) and (22) from a series to a parallel coupling. Alternatively, processor (12) responds to other inputs or conditions for actuating switching circuit (24).

Abstract: A lumped linear avalanche transistor pulse generator utilizes stacked transistors in parallel within a stage and couples a plurality of said stages, in series with increasing zener diode limited voltages per stage and decreasing balanced capacitance load per stage to yield a high voltage, high and constant current, very short pulse.

Abstract: Methods and apparatus are set forth for automatically controlling a battery back-up unit (BBU) associated with a rack mounted device, under rack A.C. power outage, rack Emergency Power Off (EPO) and normal rack power down conditions. The methods and apparatus contemplated by the invention deactivate the device BBU whenever either a rack Emergency Power Off (EPO) or normal rack power down condition exists so that BBU power is not unnecessarily drained. The invention features the ability to perform the aforestated device BBU control function without having to redesign a rack enclosure, and without having to use or generate rack signals other than "non-specific" signals, defined as signals that are being generated and used for purposes other than device level BBU switching in a commercially available rack enclosure.

Abstract: A latching relay control circuit comprising a latching relay pulse generator circuit and a relay coil drive circuit, the latching relay pulse generator circuit receiving relay control signals and relay reset signals. When a relay control signal changes states, the latching relay pulse generator provides a pulsed signal to the relay and coil drive circuit, the relay and coil drive circuit then changing the state of a latching relay. The relay reset signal is provided during power-up or just before power is lost to the system, the relay reset signal being provided to the latching relay pulse generator circuit wherein the latching relay pulse generator circuit provides a reset signal to the relay and coil driver circuit, and the relay and coil driver circuit opens all of the latching relays it controls.

Abstract: A vehicle restraint system that includes an impact sensor coupled by fiber optics to an igniter for inflating an air bag. The impact sensor includes a permanent magnet disposed within a cavity and biased by magnetic force toward one end of the cavity, motion of the magnet in the cavity being sensed by a weigand wire or Hall sensor for igniting the air bag. Facility is disposed externally of the cavity for selectively adjusting the bias of the sensor and/or moving the magnet into proximity with the Hall effect or weigand wire sensor to test operative condition of the sensor.

Abstract: A modular thyristor controlled series capacitor (TCSC) system, including a method and apparatus, uses phase controlled firing based on monitored capacitor voltage and line current. For vernier operation, the TCSC system predicts an upcoming firing angle for switching a thyristor controlled commutating circuit to bypass line current around a series capacitor. Each bypass current pulse changes the capacitor voltage proportionally to the integrated value of the current pulse. The TCSC system promptly responds to an offset command from a higher-level controller to control bypass thyristor duty to minimize thyristor damage, and to prevent capacitor voltage drift during line current disturbances. In a multi-module TCSC system, the higher level controller accommodates competing objectives of various system demands, including minimizing losses in scheduling control, stabilizing transients, damping subsynchronous resonance (SSR) oscillations, damping direct current (DC) offset, and damping power-swings.

Abstract: A system is disclosed which allows the transfer of electric power and data signals between two circuits yet allows the circuits to be electrify isolated from one another. The system comprises a loosely-coupled transformer having first and second windings separated by a sheet of insulating material. In one mode an alternating signal is applied by a first processing circuit to the first winding. An alternating signal is generated in the second winding which is rectified and then used as a power supply. In a second mode, a second processing circuit applies pulses to the second winding. Pulses are induced in the first winding which are amplified and output by the first processing circuit. Suitable first and second processing circuits are disclosed.

Abstract: A device for automatically controlling the switchover of a regular and a standby control board. A connection detecting circuit is built in each of the regular and standby control boards for determining whether or not the other control board is connected. A switching control circuit is also built in each of the two control boards for controlling the operation of the switching circuit in response to the output of the associated connection detecting circuit.

Abstract: A unitary device requiring no assembly by a user is plugged into an electrical power source to provide freeze protection. The device includes a socket for holding a heat lamp and a pressure connector, such as a plug, for connecting to an electrical receptacle or a live lamp socket. A remote sensor monitors temperature at a location remote from the device, and causes a switch to energize the heat lamp when freezing temperature is sensed. The device is supported by the plug or other connection to the power source. A commercially available heating lamp is a preferred heating element. Ease of installation and lamp replacement make the novel device highly practical for homeowner use.

Abstract: A non-contact electrical transformer coupling is disclosed that provides electrical power and full duplex digital communications between a host computer and a removable IC memory card. A unique two-part host magnetic core assembly having a quadrafid design forming multiple poles is provided with printed circuit windings and is disposed to receive the IC memory card embedded with core pole pieces and associated printed circuit card windings to complete the magnetic flux paths and transformer coupling. The configuration of the poles and windings form completely independent channels, each of which behaves like a wide-band ferrite core transformer. The independence of each channel enables this unique magnetic core and associated windings to couple relatively large amounts of power to the circuitry of the IC memory card and establish a high-speed bidirectional data link between the host and card.

Abstract: The invention relates to a liquid sensing switch for use primarily in sensing the bilge water level aboard a boat. The switch is designed with a high input impedance and a high trigger sensitivity, so that the presence of a liquid may be detected by using a remotely located single wire probe. The probe is able to sense immersion into low conductivity liquids or into liquids where no hardwired ground is provided, such as within fiberglass boat hulls. In order to prevent false triggering and cyclic operation of the bilge pump, the liquid sensing switch provides a time delay before it is activated, as well as a further time delay before being deactivated.

Abstract: A method and apparatus are described for selectively activating a secondary power source, such as a backup battery, for an electronic device, such as dynamic RAM. A connector is described in conjunction with a circuit board including a first contact coupled to the backup battery, and a second contact coupled to the corresponding input for backup power associated with an electronic device. In this state, an open circuit is presented such that the battery is isolated from the electronic device. A socket is described for cooperating with the connector, which includes mating contacts corresponding to the first and second contacts previously described, and a shunt for establishing electrical continuity between these mating contacts. In this manner, a completed circuit is established between the battery and the electronic device when the socket is attached.

Abstract: A secondary battery equipped power supply is provided with charging and related circuitry such that when placed in a location, such as in a DC powered electrical transit system, where there are normal, surge and continuous peak demands placed on the primary DC supply, the battery charges during normal operation and discharges to provide additional power on the occasion of a surge or peak demand.

Abstract: Apparatus for ionizing a gas. The apparatus includes an ionizing generator with an insulating frame, an electrical insulator and a conductive brush formed of individual bristles. An ionizing power supply connects to the conductive frame and the electrically conductive brush. When a threshold potential is applied by the power supply, ionizing discharges emanate from the free ends of individual conductive wires in the brush and establish discharge paths with the conductive frame thereby to produce a volume of ionized gas.

Abstract: False ac signals produced by a noise suppression capacitor across a switch applying a switched ac line voltage signal to a logic input of a microprocessor in an electrical apparatus such as, for example, a contactor or circuit breaker, are phase shifted with respect to a true ac input by inserting two series resistors, and a diode shunting one resistor, between the switch and the logic input. This creates a larger window in which to discriminate between the zero crossings of the true and false ac signals.

Abstract: A transistorized source power coupler for coupling a power source to a pair of transmission lines. DC power from the power source is conducted by the transistorized source power coupler to the transmission lines. Meanwhile, AC signals on the transmission lines are isolated from the power source by the source power coupler. Consequently, the same pair of transmission lines can be used to supply power to cells of a communications system while also conducting data signals between those cells with minimal effect to the power source.

Abstract: An electrostatic chuck has a substrate, an insulating layer disposed on the substrate for attracting a workpiece thereto, and an electrode interposed between the substrate and the insulating layer. The insulating layer having a volume resistivity .rho.(.OMEGA.m), a dielectric constant .epsilon..sub.r, and a thickness d (m), and being spaced from the workpiece which is attracted thereto by a gap having a distance .delta.(m). The volume resistivity .rho., the dielectric constant .epsilon..sub.r, the thickness d, and the distance .delta. satisfy the following relationship:1.731.times.10.sup.-11 .rho.{.epsilon..sub.r +d/.delta.}<60.