CHARGING CIRCUIT AND CHARGING METHOD FOR THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a charging circuit that reconciles protection of a switching element and reduction in energy loss.SOLUTION: The charging circuit for charging a storage battery as controlling an output from an external power supply such that a current value decreases with charging time includes: a power semiconductor switching element for switching a DC output from the external power supply on/off to control power; a snubber circuit connected in parallel with the power semiconductor switching element; a snubber circuit isolation switch connected in series with the snubber circuit; a current sensor section for measuring a current value on a line connected to the storage battery; and a control circuit for turning the snubber circuit isolation switch on/off on the basis of an output of the current sensor section. The control circuit turns the snubber circuit isolation switch on to connect the snubber circuit at the start of charging. The control circuit turns the snubber circuit isolation switch off to isolate the snubber circuit when the current value decreases to a predetermined current value with charging time.