| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply switching device for switching a power supply units to be input and outputting the power, which can solve the problem that both the power supply units cannot output power or both the power supply units output power in power failure or fault of a controller section, and to provide a power supply system. <P>SOLUTION: Two power supply units, i.e. a commercial power supply 1 and an inverter 4 are both connected in parallel via switching elements interposed and are connected to output terminals, and a drive voltage is applied from a control circuit 8 is applied to a gate electrode of the switching elements. The switching elements 11a, 11b interposed on the commercial power supply 1 are conducted when a potential is not detected between a gate and a source, and the switching elements 11c, 11d interposed on the inverter 4 as the other power supply unit are opened when a potential is not detected between the gate and the source. Thus, if a drive voltage is not generated because a control circuit 8 is in a power failure or fault, the power from the commercial power supply 1 can be supplied to a load via the switching elements 11a, 11b and the output terminal 7. <P>COPYRIGHT: (C)2009,JPO&INPIT |
