AN ARRANGEMENT IN A POWER SUPPLY UNIT

摘要

In a power supply unit, an AC power driven rectifier (2) and an unprioritized load (5) are connected to a busbar (1). A prioritized capacitance-containing load (6) is connected to the busbar (1) via a diode (D1) and via a first contactor (7) in series with a second contactor (8). A battery (4) is connected to the busbar (1) via the first contactor (7) for supplying power to the busbar (1) upon an AC power failure until a certain discharge of the battery (4), whereupon the first contactor (7) opens to disconnect the unprioritized load (5). The prioritized load (6) receives power via the second contactor (8) until the battery (4) has been discharged further, whereupon the second contactor (8) opens. When the AC power failure ends with the contactors (7, 8) open, power is supplied to the prioritized load (6) via the diode (D1), whereupon the first and second contactors (7, 8) are closed in that order to supply power to the battery and the prioritized load (6).