| 摘要 |
<p>PURPOSE:To turn off a power source without fail without requiring back-up of the power source by delaying the operation of a power source turning-off switch for a constant time and turning off the power source forcibly when the turning-off control cannot be executed. CONSTITUTION:A control part 11 reads ON/OFF through a switch reading circuit 9 by a control program, and when a power source switch 7 is OFF, the part turns off the power source through a power source turning off circuit 17. When the control program is written to a RAM 15 and the power source turning off switch 7 cannot be read by the abnormality of an external memory part 12, a ROM 14, a RAM 15, a non-volatile memory 16, etc., after the power source turning-off switch 7 cannot be read by a timer circuit 10, the power source turning-off signal is outputted to a latching relay 18 and the power source is forcibly turned off. Thus, without needing the power source back-up at the time of turning off the power source, the power source can be turned off without fail.</p> |
