DC/DC CIRCUIT FOR UNINTERRUPTIBLE POWER SUPPLY

A DC/DC circuit (8) for an uninterruptible power supply, which is a bidirectional DC/DC circuit (8) and connected to a battery (B) and a bus bar. In a mains supply mode, the bidirectional DC/DC circuit (8) draws power from the bus bar and charges the battery (B), and when the mains supply is abnormal, the bidirectional DC/DC circuit (8) works in a state that the battery (B) supplies power to the bus bar. The bidirectional DC/DC circuit (8) includes an isolation transformer. The primary side of the isolation transformer is connected to a push-pull circuit or a half-bridge circuit or a full-bridge circuit, and the secondary side of the isolation transformer is connected to a push-pull circuit or a half-bridge circuit or a full-bridge circuit. The bidirectional DC/DC circuit (8) performs turn ratio switching by selecting the taps of the primary side or the secondary side of the isolation transformer for charging and discharging voltage regulation. The DC/DC circuit for an uninterruptible power supply makes the UPS system simpler and at the same time reduces the system costs.