| 摘要 |
PROBLEM TO BE SOLVED: To provide an intercom system by which even a bi-call/bi-video intercom system can be connected to an in-house intercom with a cable less in the number of cores. SOLUTION: In the case of receiving a speech signal from a speech line 1 and a video signal from a video line 1, a speech relay contact 11 of the in-house intercom 10 is closed, a DC voltage is applied to a one-video relay coil 2 through a video branch line 23 to throw a one-video relay contact 2a to a position of the video line 1, and in the case of receiving a speech signal from a speech line 2 and a video signal from a video line 2, the speech relay contact 11 of the in-house intercom 10 is closed, a DC voltage is applied to two-call and two-video relay coils 3, 4 through the video branch line 23 to throw a 2-call relay contact 3a to a position of the speech line 2 and to throw a two-video relay contact 4a to a position of the video line 2. COPYRIGHT: (C)2006,JPO&NCIPI
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