| 摘要 |
<p>PURPOSE:To improve reliability by detecting the existence of abnormality at a peripheral circuit by measuring energy consumption in a reset state and comparing it with energy consumption in a normal case. CONSTITUTION:The AC power source of AC 100 volts is turned to power failure, power is supplied from a battery 11 to a frequency divider circuit 4, CPU 5, display circuit 6 and oscillation circuit 7 although there is no power supply to a W/F circuit 3. When the power failure is detected, the CPU 5 stores electric energy calculated just before the power failure and transmits a reset signal to the frequency divider circuit 4 and afterwards, the oscillating operation of the oscillation circuit 7 is stopped. The display circuit 6 continuously displays the electric energy stored in the CPU 5. At such a time, a flip-flop is turned to an initial state in the frequency divider circuit 4 by the reset signal and turned to a fixed output state regardless of the number of pulses before that. Therefore, when the energy consumption of the frequency divider circuit 4 in this initial state is set at an abnormal level larger than the normal energy consumption, the existence of a defect is judged.</p> |
