| 摘要 |
PROBLEM TO BE SOLVED: To obtain a multiple dwelling house interphone system where power consumption in a standby state is suppressed. SOLUTION: A power supply circuit 33 rectifies an AC power at a low price time zone at night designated by a clock 35 of a control unit and a charging circuit 34 receiving the rectified AC voltage charges a battery 36, from which a DC voltage is applied as an operating power supply to a security monitor function of a plurality of living room master sets 1a, 1b,... and a multiple entrance unit 3 and a control unit 4 in a standby state. Furthermore, as an operating power supply for each living room master set controlling a call detection function from individual entrance units 2a, 2b,... connected individually, a commercial power supply AC is rectified by a power supply circuit 33 resulting in a DC voltage via a power supply circuit 37 and a power switch circuit 10 is used. A DC voltage fed from the power switching circuit 10 receiving a start signal transmission circuit 32 of the control unit is used for the operating power supply of each living room master set when it is called from the multiple entrance unit 3. Commercial power supply is used for the operating power supply controlling a security report function.
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