Diode faults detecting apparatus

摘要

First and second diodes are formed on the same semiconductor substrate. Both the diodes are forward biased by a direct current power supply. An attenuator is connected to a positive terminal of the first diode to produce an output lower in level than a voltage on the positive terminal of the first diode. A comparator receives the output of the attenuator as a first input and a voltage on a positive terminal of said second diode as a second input. When the first input is smaller than the second input, the comparator produces an output "0." When the first diode is open-circuited and the first input becomes greater than the second input, the comparator produces an output "1" and detects the fault of the first diode.