| 摘要 |
PURPOSE:To reduce a standby current and accelerate the response speed of the remote control of operation start, by increasing the input impedance of a detecting circuit connected to an output line, and preventing a capacitor between the output side of an audio amplifier and the output line from being changed at the non-operation time. CONSTITUTION:The output side of an audio amplifier 1 which amplifies a reproduced signal is connected to a DC power source 6 through a series circuit consisting of capacitors 3L and 3R, output lines 4L and 4R, and an electroacoustic transducer 8. A headphone 26 is connected to a jack 5, and a voltage is applied to the output line 4L by the connection of the first switch 26a, and a DC voltage detecting circuit 15 which has the input impedance increased is connected to the output line 4L. At the non-operation time, the second switch 26b disconnects the capacitor 3R from the DC power source 6. The change of the DC voltage of the output line 4L due to turning-on and off of the first switch 26a is detected by the detecting circuit 15, and the operation of a reproducing device is controlled by the detection output. |
