| 摘要 |
PROBLEM TO BE SOLVED: To provide an intercom device capable of generating an alarm sound from other master units without increasing the number of signal lines when a detection signal is input by a sensor provided in correspondence with one master unit in the intercom device in which a plurality of master units are provided for a slave unit. SOLUTION: When a sensor 30 transmits a detection signal, a master unit 10 provided with the sensor 30 has a control unit 17 control a sound converter 14 to generate an alarm sound from a speaker 13. Also, the control unit 17 controls a switch 106 of a power supply control/monitoring part 19, so that, for instance, it switches on/off at prescribed intervals. Therefore, during an ON period of the switch 106, a transistor 101 is switched on and voltage which divides voltage (Vcc) of a power supply part 20 according to a resistor ratio of resistors 102 and 105 is supplied for a signal line 8 ((d) in Fig.3). Another master unit 10 has the control unit 17 control the sound converter 14 to generate an alarm sound from the speaker 13 when voltage value of the (d) is detected. COPYRIGHT: (C)2009,JPO&INPIT
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