Abstract: The present invention relates to battery power system configurations, particularly systems using VRLA batteries in uncontrolled environments wherein the batteries are isolated from the rectifier when the batteries are in the float mode but on line during charge and discharge. The battery power system configuration of the present invention eliminates thermal runaway because the current drawn by each battery is limited to the value determined by a constant current source. A shorted battery cell may be easily detected by observing if the voltage of the battery is lower than a specified and expected value. In addition, battery capacity is maintained by the boost provided periodically from the current source. Finally, batteries are protected against receiving excessive current and since the currents sent through the batteries match the needs of these particular batteries, the life of the batteries is increased.

Abstract: For use with a grounded power plant, capable of powering a load, having a power supply and a power distribution system, a protective circuit, including a voltage clamping device, coupled between a return conductor of the power distribution system and the ground, that attenuates voltage transients present in the return conductor of the power distribution system thereby preventing the voltage transients from damaging the load.

Abstract: An isolation circuit for use in a power plant having a first power supply that powers a first load and a second power supply that powers a second load. The first and second power supplies are cross-couplable via a first and second auxiliary path to allow the first power supply to power the second load and the second power supply to power the first load. The first power supply is subject to a reverse current by way of the first auxiliary path. The isolation circuit includes a first switch, located in the first auxiliary path, that substantially reduces the reverse current flowing into the first power supply thereby enhancing an isolation of the first power supply. A controller is, also, provided that monitors the first switch thereby enhancing a reliability of the power plant.

Abstract: A reserve power system for a commercial AC load provides DC power to the load when the primary power fails by providing direct current voltage power from a DC power source which enables the load to continue to operate in a normal fashion. A power system supplying commercial AC derived power to a load provides backup power by coupling DC power to the load when the primary AC power fails. AC power is supplied to a primary winding of a power transformer which also has a secondary winding side. A cable is connected, at a first end, to the secondary winding side and at a second end to a load powered by a commercial AC voltage. A battery DC voltage source and a battery charger are connected to the secondary winding side of the power transformer. The battery charger maintains the integrity of the reserve power. A voltage monitoring circuit connected to the power transformer detects a primary power failure and activates switching circuitry for connecting the DC voltage source directly to the load.

Abstract: A bipolar switching circuit converts an applied DC voltage to a low frequency AC voltage by periodically transmitting and inverting the applied DC voltage. The bipolar circuitry in one embodiment includes four switches which are switched in pairs to alternately provide a direct transmission of the input DC voltage and an inverted version of the DC input voltage.

Abstract: A UPS system includes a backup input line isolation switch and control circuit for energy flow in the UPS is operative, during operation of the reserve energy source portion of the power supply in supplying power to the output, to provide mechanical isolation between the primary energy source connected to the input line and the secondary energy source upon detection of a failure of an electronic isolation switch normally providing isolation between te input line and the secondary energy source or an output of the UPS.

Abstract: An inductor structure is combined with a ferroresonant regulator as a filter inductor in one instance, and as a regulating inductor in another. In one example, a ferroresonant voltage regulator includes a pair of shunt filters at its output to reduce the low order odd harmonic content of the AC output. The filtering arrangement includes two LC shunt filters having their independent inductor windings wound on a single magnetic core unit. Auxiliary windings coupled to each of the inductor windings are placed in series with the output to buck any remaining harmonics.In a second instance, independent regulating inductors in a multiphase ferroresonant regulator are also realized on a single magnetic structure.

Abstract: A signal coupling arrangement including a dual detector opto-isolator arrangement operative to transfer a sensed DC signal from an input to an output of an amplifying circuit with an isolated electrical system there between incorporates amplifiers having a specific gain set by unique calibration means and to initially preset the coupling circuitry amplification gains to assure a consistent DC current transfer and DC contrast ratio in coupling DC signals from the input to the output.

Abstract: A three-phase rectifier utilizes three feedback controlled ferroresonant regulators to convert a three-phase signal into a regulated DC voltage. A monitoring circuit is included which responds to a signal loss at any input phase to actuate an alarm signal.