| 摘要 |
PURPOSE:To inhibit the operation when a switch is failed by providing a circuit presetting a semiconductor switch and a command circuit starting a device when a switch is turned once on and restored off after receiving a preset signal. CONSTITUTION:A switch circuit is provided with the semiconductor switch 1 and when an output (a) of a transistor (TR) of the switch 1 goes to L, a relay K1 of the preset circuit 2 is turned on and the setting state is held. Further, when the switch 1 is turned off and the output (a) is at L level, a current flows to a relay K2 of a preset circuit 3, and the relay K2 of the circuit 3 is turned off by flowing the current to the TR. A contact K1-2 of a power-on command circuit 4 is turned on and the K2-1 is turned off in this case. Then, when the switch 1 is restored to off, a current flows to the relay K2 of the circuit 3, the contact K2-1 of the circuit 4 is closed, a command is given to a power-on sequence circuit 5 from the circuit 4 by closing the contact K1-1 so as to inhibit the operation when the switch 1 is failed. |
