| 摘要 |
<p>PURPOSE:To enable change-over a sound volume and an audio equipment automatically set respectively to two operating states, by controlling a level adjusting circuit and audio equipment switching circuit through the provision of a timer with the acoustic playback system. CONSTITUTION:Tuner 11, record player 12, and tape deck 13 are connected to the speaker 18 via the switching circuit 14, preamplifier 15, and control circuit 16 and the like. The system is provided with a timer 20, and for example, the 1st time for sleeping and the 2nd time for awakening are set, and the 1st and 2nd moving contacts of the switching circuit 14 are connected to the deck 13 and the tuner 11 at the same time. First, the deck 13 is made to playback state. In this case, the variable resistor of the control circuit 16 is controlled so that sound volume is adjusted not to interfere the sleeping. When time reaches the 1st set time, the playback is stopped. Next, time comes to the 2nd set time(morning), the playback signal is played back from the speaker 18 via the tuner 11 in set sound volume. With the constitution like this, the change-over to set sound volume and set audio equipment is made.</p> |
