| 摘要 |
PURPOSE:To discriminate the off-state of a switch from the faulty state of a circuit by providing a first input circuit to output a signal when the switch is turned on, and a second input circuit to output the signal when the switch is turned off. CONSTITUTION:The subject circuit is composed of the input circuit 2, the input circuit 2A with the same constitution as that of the input circuit 2, and the switch 1A consisting of a contact (a) connected between a DC power source and the input circuit 2 and a contact (b) connected between the DC power source and the input circuit 2A. The signal is outputted from the input circuit 2 when the switch 1A is turned on. Also, the signal is outputted from the input circuit 2A when the switch 1A is turned off. Thereby, since no signal is outputted when a fault occurs in the circuit, the off-state of the switch can be discriminated from the faulty state of the circuit. |
