| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a power failure detector transmitting power failure signals from a plurality of sources by one common line and providing immediate specification of a failed power source by a number of a lighted LED. SOLUTION: The power failure detector is an electronic apparatus system composed of a plurality of boards and trading power supply voltages and signals with the plurality of boards by a backboard. It is provided with comparator groups comparing respective power supply voltages with a predetermined reference voltage on each of the plurality of boards, respective inherent duty ratio oscillator groups oscillated by malfunction detections of each comparator, the common line on the backboard transmitting oscillation signals of the respective inherent duty ratio oscillator groups, an averaging circuit integrating the oscillation signals transmitted from the common line and converting them into direct current voltages, and a second comparator group transmitting fanout signals to an AND gate and respective LEDs of a display part as a result of applying the direct current voltages of the averaging circuit to respective second comparators and comparing the direct current voltages with predetermined inherent reference voltages by the respective second comparators.</p> |
