| 摘要 |
PROBLEM TO BE SOLVED: To provide a power-supply switch circuit that detects the presence or the absence of a signal added to an input part or the presence or the absence of a connection between an output part and external equipment, and also, controls power supply for each circuit to process a signal from the input part or a signal to the output part in conjunction with the detected results. SOLUTION: The power-supply switch circuit 10 is provided with: input-signal processing circuits 17, 18 for processing input signals from a plurality of input terminals 11, 12; output-signal processing circuits 20, 21 for processing output signals to a plurality of output terminals 30, 31; an input-signal detection circuit/output-connection detection circuit 15; and a control circuit 14. The control circuit 14 controls power supply to the output-signal processing circuits 20, 21 corresponding to the presence or the absence of a connection with an external signal line in the output-connection detection circuit 15, while controlling power supply to the input-signal processing circuits 17, 18 corresponding to the presence or the absence of the input signals in the input-signal detection circuit 15. COPYRIGHT: (C)2008,JPO&INPIT
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