POWER SUPPLY DEVICE

摘要

There is provided a power supply device having a generator driven by an engine and capable of performing effective operation even in a small-load range. The generator (1) is driven by an engine. The output of the generator (1) is converted into AC power of a predetermined frequency by a rectification circuit (2) and a power conversion section (4) (DC regulator (4-1) and an inverter (4-2)) and output to the load side. A bidirectional DC-DC converter (5) supplies power of a battery (6) to the input side of the power conversion section (4). When the load current is not greater than a predetermined value, power supply to the load is performed by the output of battery generation by the battery (6) without using the output of the generator generation by the generator (1). When the power supply capacity of the battery (6) is lowered, power supply to the load is performed by the output of the generator generation and the battery (6) is charged.