UNINTERRUPTIBLE POWER SUPPLY

摘要

An uninterruptible power supply (UPS) has an AC input (13) coupled to the primary winding (30) of a transformer (32) via an AC to DC converter (16) and a switching circuit (X1). A hold-up capacitor (17) is coupled across the output of the AC to DC converter. The supply also has a DC input X10 coupled to a tertiary winding of the transformer (32) via a DC to DC converter (15) and a second switching circuit (X5). A battery (64, 66) is arranged to be charged from a secondary winding (36) of the transformer which winding also provides a regulated DC output. Switching means (70, 80) are provided for driving the DC output from the battery in the event that AC or DC voltages supplied to respective inputs fail.