| 摘要 |
PURPOSE:To hold information without requiring a backup battery even at the time of break of power supply by using a single stable type relay driven and controlled in accordance with the monitor result of a supply voltage and a latching type relay which controls information holding to a latch circuit. CONSTITUTION:A supply voltage monitor circuit 1, a single stable type relay 4 driven through a first relay driver 2 by the output of this circuit 1, and a latch circuit 6 which loads held information at the time of power-on and updates information to be held are provided. A latching type relay 5 is provided to which the supply voltage is supplied from the contact of the single stable type relay 4 and in which information to the latch circuit 6 is held through a second relay driver 3. When a power source is turned off, driving of the single stable type relay 4 is released through the relay driver 2, and the supply voltage supplied to the latching type relay 5 is broken. Thus, information before break of power supply is stored in the latch circuit 6 without requiring a battery backup system.
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