| 摘要 |
PURPOSE:To stop the power supply to a remote control device when no signal is transmitted from the remote control device to a device to be controlled or a transmission error is caused by providing a relay circuit turning on/off the power supply to the remote control to the said device. CONSTITUTION:When a microcomputer 8 flows a current to a resistor 15 of a relay circuit 14a and turns on a transistor 17, a coil 18 is energized, a switch 20a is turned on and a signal and a current are applied to the remote control device 2a. Further, if any transmission error is produced or no signal returns from the remote control device 2a because of a failure of the remote control device 2a or short-circuit of transmission lines 3a, 3b, the power application to the coil 18 is stopped, the switch 20a is turned off so as to stop the power supply to the remote control device 2a. Moreover, no signal returns to the microcomputer 8 or any transmission error is caused again by turning on the switch 20a by means of the relay circuit 14a, the switch 20a is turned off again. Then the relay circuit 14b turns on the switch 20b and the same operation is performed. The same procedure is performed as to the relay circuit 14c. |
