| 摘要 |
PROBLEM TO BE SOLVED: To control the power on and off of a device which is in waiting condition usually far off, through a communication line. SOLUTION: A power on signal is sent to a secondary device 12 connected through a communication line 10 from a primary device 11. This signal passes a normal-close relay SW 2 through a path 14, and actuates switches SW1 and SW2, and connects an external power source to the secondary device 12. While the secondary device 12 is open, the relay SW 2 is opened by control signals CL1 and CL2 to interrupt the signal from the path 14 and also supply the switch SW1 with power for operation. When a shut down signal reaches it from the primary device 11, a control circuit 15C returns the secondary device 21 into its former waiting condition by returning the control signals CL1 and CL2 into their initial conditions. |
