| 摘要 |
PURPOSE:To detect stably a disconnection under various conditions by providing a current-voltage converting means for generating a voltage by a current of an extent that a device to be started is not started, a reference voltage generating means and a voltage comparing means. CONSTITUTION:In a starting device side of a signal line 2 for connecting a start signal sending-out part 1 and a start signal detecting relay 4, a current-voltage converting part 6 for sending out a current I2 by which a device to be started in not started, and generating a voltage VP by the current I2, and a reference voltage generating part 7 for outputting a reference voltage VS are conncted to a voltage comparing part 8. In such a state, the comparing part 8 indicates the voltage VS<VP, but when the signal line 2 is abnormal, the current I2does not flow and the voltage VP is varied, and the comparing part 8 is constituted so as to generate an output as an abnormal state, namely, a disconnected state. In such a way, a factor for causing malfunction or non-operation is eliminated, and an electric condition for stable operation can be set. |
