| 摘要 |
PURPOSE:To attain call and talking among plural households by providing a switch setting a calling between households to plural interphone master sets and connecting the dialing line and the calling line between the interphone master sets. CONSTITUTION:In making a call from a doorphone slave set 12 to an opposed household, when the talker of an interphone master set 10 turns on a 2-household switch 11 and a 2-household call switch 106 on the request of a talker of the doorphone slave set 12a, a logic circuit 101 switches a relay 103c to connect a talking circuit 107 to a talking line L1 and sends a call signal to an interphone master set 20 via an output latch circuit 104 and a call line L2. Thus, when the 2-household changeover switch 11 is turned on and the 2-household call switch 106 is turned on, doorphone slave sets 12a, 12b, 22a, 22b used for one household can be talked with the opposed interphone master sets 10, 20 respectively.
|
