Switching current spike limiter for three phase coupled inductor conductive battery charger

Abstract

A polyphase boost inductor battery charger having a switching current spike limiter that employs a switching transistor, such as a bipolar, MOSFET, or IGBT transistors, for example. The switching current spike limiter includes a controller whose inputs are coupled to receive AC line voltage from a power source and battery voltage from a battery. A comparator is coupled to receive the AC line voltage and the battery voltage. Outputs from the controller and the comparator are coupled to an OR gate. An output of the OR gate is coupled through a switch driver to a series pass switch which comprises the switching transistor. The switching transistor is coupled to the inductor. A flyback diode is coupled across the output of the switching current spike limiter. The switching current spike limiter controls current spikes that flow when the AC line voltage (V.sub.AC) peak is greater than the battery voltage (V.sub.batt). To determine the condition V.sub.AC peak>V.sub.batt necessary for the switching transistor to be held OFF, the AC line voltage is compared to the battery voltage in the comparator. Hysteresis is applied to the comparator to avoid high frequency oscillation at its output.

Dependencies are inferred from the claim text.