Abstract: A battery charger, a method of charging a battery and a battery plant incorporating the battery charger or the method. In one embodiment, the battery charger includes: (1) a battery voltage monitor that measures a voltage of a battery and (2) a charge current generator, coupled to the battery voltage monitor, that provides an incrementally adjustable charge current to the battery based on the voltage.

Abstract: A bus holdup circuit for a module of a distributed power system, a method of bolstering bus voltage and a distributed power system employing the circuit or the method. In one embodiment, wherein the module has a backplane interface adapted to be removably coupled to a DC backplane of the distributed power system, the bus holdup circuit includes: (1) an energy storage circuit, coupled across the backplane interface, adapted to store and dissipate energy to bolster a voltage across the DC backplane and (2) an inrush limiting circuit, series-coupled to the energy storage circuit, adapted to limit an inrush current to the module.

Abstract: For use in a module, a redundancy detection circuit for, and method of, determining whether a predetermined adequate redundancy exists when the module is present in a system. In one embodiment, the module includes: (1) a sensor, associated with the module, that receives a signal that is a function of a number of modules present in the system and (2) a calculation circuit, coupled to the sensor, that determines from the signal whether a surplus capacity of the module provides at least the predetermined adequate redundancy for the system.

Abstract: In a partitioned power converter system having a central uninterruptible power supply ("UPS") stage couplable between a commercial power source and a peripheral stage, the central UPS stage including a primary converter that converts commercial power from the commercial power source to a distribution voltage; a battery boost converter, coupled to a battery reserve system, that boosts a battery voltage produced thereby to the distribution voltage; and mode switching circuitry that alternatively couples one of the primary converter and the battery boost converter to the peripheral stage, selective bypass circuitry and a method of increasing the efficiency of the power converter system.

Abstract: For use in a battery reserve system having a reserve battery, a charging circuit coupled between a source of electrical power and the reserve battery for charging the reserve battery and a heating element in thermal communication with the reserve battery for increasing a temperature of the battery, a mode selection circuit and method of operation thereof. The mode selection circuit includes: (1) a temperature transducer, coupled to the reserve battery, for sensing the temperature of the reserve battery and (2) a mode-changing circuit, coupled to the temperature transducer, for selecting an alternative one of: (a) a heating mode wherein the source of electrical power is coupled to the heating element when the temperature of the reserve battery is less than a reference temperature thereby to heat the reserve battery and (b) a charging mode wherein the source of electrical power is coupled to the reserve battery when the temperature is greater than the reference temperature thereby to charge the reserve battery.

Abstract: The cost and energy efficiency of a power supply are optimized in a semi-regulated circuit wherein regulation occurs only under a high voltage, low current condition when peak output voltage would otherwise exceed a maximum specified voltage. The circuit includes a full wave rectifier (21-24) driving a modified pi filter (33-35). A transistor (62) in series with the filter is biased by a resistor (65) to normally operate in a fully saturated, low power dissipating mode. When the output (31-32) voltage approaches the specified maximum, the breakdown voltage of a zener diode (71) is exceeded, and the output voltage is clamped to the specified maximum through the zener diode and the base-emitter junction of the transistor.