| 摘要 |
PURPOSE:To surely detect the opening/closing condition of a door with a low- cost device by arranging a projector on one end and a photoreceiver on the other end of the front of a switchboard row where a plurality of switchboards are arranged in a row thereby constituting a photocoupler. CONSTITUTION:A plurality of switchboards 1a, 1b,... are arranged in a row to costitute a switchboard row 10. A projector 4A, on one end of the front of the switchboard row 10, and a photoreceiver 4B, on the other end, are arranged to costitute a photocoupler. The projected light L between the projector 4A and the photoreceiver 4b is set in the position contigous to the panel face so that it may be intercepted when doors 2a, 2b,... open. An opening/closing detector 4 for a switchboard door lights the projector 4A and detects the existence of the output of the photoreceiver 4B. Hereby, the opening/closing condition of the door can be detected accurately with a low-cost device. |
