| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power supply unit capable of preventing a malfunction of a switch due to leak current, which is parallel connected to a rush current limiting resistor provided for prevention of the rush current at power supply start. <P>SOLUTION: This power supply unit includes a current detection means for detecting AC current on both hot and cold sides of an AC power supply respectively. The outputs of the two current detection means are supplied to an AND circuit and, by the output of the AND circuit, a relay is operated to open the switch parallel connected to the rush current limiting resistor, thus activating the relay completely. The addition of the AND circuit prevents malfunctions due to the leak current. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
