| 摘要 |
<p>PURPOSE:To prevent an error operation to put on a display device without turning off the power source by providing a mechanical lock member to stop an elevator board at the elevated position, composing the system to drive the lock member with a solenoid, and turning on and off the driving power source of the solenoid linking to the power source of the display device. CONSTITUTION:By elevating a display device 4 and turning on a power source switch 5, the coil of a main contact 17 is excited to close the main contact 17, and the power source is supplied to distributor outlet sockets 21 and 22 and a CPU 23. And a power source maintaining signal output from the CPU 23 excites the coil of a self-maintaining contact 18 passing through an amplifier 25, to close the self-maintaining contact 18, and the closing condition of the main contact 17 is maintained. While the power source of the display device 4 connected to the distributor outlet socket 22 is turned on, the coil of an extension contact 15 connected to the distributor outlet socket 21 is excited to close the extension contact 15, and the power source is supplied to extension outlet sockets 26 and 27. As a result, a solenoid 9 to drive a locking pin is driven to project the locking pin 8, and the movement of an elevator board 3 is prevented.</p> |
