| 摘要 |
<p>PURPOSE:To make able to perform testing correctly of an amplifier, a comparator, a time limitting circuit, a switching circuit and a reset circuit by making to detect a signal from a detecting resistor constituting so as test resistances to be in parallel with a real electrical route. CONSTITUTION:When pressing a test button 23, a current supplied by a direct current power source 20 flows to a test resistor 24 through a current limitting resistor 14 and a detecting resistor 6 and a closed circuit to return to the direct current power source 20 is established. At this time a signal is generated at both ends of the detecting resist 6 by a current flowing through the detecting resistor and causes to simulate an exactly similar phenomenon as that of an insulation deterioration of either one of electrical routes 1 - 3. Accordingly by determining a resistance value of the test resistor 24 in accordance with a supervising insulation resistance value a state near to areal failure can be achieved and can withness normal operations of an amplifier 71, a comparator 72, a time limitting circuit 73, a switching circuit 74 and of a reset circuit 25.</p> |
