| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a power supply circuit for backup that stably switches the power supply by simple circuitry without requiring high equipment cost. <P>SOLUTION: A power supply circuit for backup provided in a DC power supply circuit which supplies power from a DC power supply 32 to a load via a main power supply line 30 includes a power supply 38 for backup which generates a DC voltage for backup, a line 40 for backup which connects the power supply for backup with the main power supply line, a normally open first relay 42 provided in the way of the main power supply line and being driven with power from the DC power supply, and a normally closed second relay 44 provided in the way of the line for backup and being driven with power from the DC power supply. With such an arrangement, the power supply is switched stably by simple circuitry without requiring high equipment cost. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
