| 摘要 |
PURPOSE:To supply the outputs of sources to a speaker simultaneously or selectively by providing one mixing circuit and plural power switches. CONSTITUTION:With a switch SW1, transistors (TR) Q4-Q7 turn on to power up a reception part, a mixing circuit 107, and an audio amplification part 12 through power lines L1-L4, holding a receiver in readiness. In this state, when a switch SW2 is turned on, the mixing circuit 107 inputs a signal from the reception part and that from a tape deck 11 to output a mixed signal. Then when the switch SW1 is turned off and the switch SW2 is turned on, the TRs Q4 and Q6 thurn on to power up the mixing circuit 107 and audio amplification part 12, so only a playback sound by the tape deck 11 is listened to through a speaker 13. |
