A reliable uninterruptible DC power supply device. The DC backup power supply device includes an AC/DC converter (2), a DC/DC converter (3), voltage step-up/down choppers (151, 152, 16, 18) and a battery (19) connected to a DC path of a main circuit connec...

This includes a recharging circuit which has supply terminals (1), normally for alternating current, a voltage-reducing circuit formed of a resistance (10) or a transformer (11), charging terminals (2) and an overload-prevention circuit (4) consisting of a...

An optimizer circuit (24) is interposed between a DC bus (14) and a battery (18) of a power supply system, including two converters (29, 30) in parallel, one that can lower the battery voltage below the bus voltage or directly connect the bus (14) to the b...