| 摘要 |
PURPOSE:To make the current flowing to an alarm generation circuit constant by selecting a protection resistance to a proper value and using a drain-source saturation current IDSS of a FET when any of fuses is blown. CONSTITUTION:One terminal of contacts 3a-3c connected synchronously in the occurrence of a fault is connected to a power source input terminal 1 and the other terminal is connected to a series circuit, protection resistors 4a-4c and diodes 5a-5c in multiple. The multiple connecting point is connected to a gate G and a source S of the FET 6 and the drain D is connected to an alarm generating circuit 7. Through the constitution above, in the proper selection of the protection resistor 4, the current flowing to the alarm circuit is kept always constant by the drainsource saturation current IDSS of the FET 6. Thus, the alarm detection point is constituted independently. |
