| 摘要 |
PURPOSE:To perform bidirectional transfer efficiently by providing the first mixing and separating circuit in the audio device side and providing the second mixing and separating circuit in the speaker side and using an audio signal transmission line to perform frequency division transmission. CONSTITUTION:The audio signal from an audio device 1 is amplified by a power amplifier 2 and is applied to the first mixing and separating circuit 3 and is mixed with a DC power source voltage from a supply terminal for DC power source voltage and is transmitted to n audio signal transmission line 8. Te audio signalf and the DC power source votage from this transmission line 8 are separated from each other by the second mixing and separating circuit 9, and the audio signal is applied to a speaker 10, and the DC power source voltage is applied to a control code signal generato?r 11. Control code signals CS1-CSn generated by this generator 11 are sent to the mixing and separating circuit 3 through the transmission line 8, and signals CS1-CSn separated by the circuit 3 are amplified by an amplifier 5 and are binarized by a binarizing circuit 6. These binarized control code signals are applied to a control voltage generating circuit 7, and a control voltage generated by the circuit 7 is applied to the device 1, thus performing bidirectional transfer efficiently. |
