| 摘要 |
<p>PURPOSE:To realize a tape recorder with a broadcasting radio receiver having a sleep function by adding a switching circuit operating at the time silent period of the broadcasting radio receiver to a non recorded sound part detection circuit. CONSTITUTION:The output signal of a detection circuit 5 forming a radio receiving circuit A is inputted to the non-recorded sound part detecting circuit 15 through a non-silent part detection signal amplifier 14 when a sleep on/off switch 7-1 is turned on. The presence and the absence of a radio signal is detected, a sleep power source interrupting switching transistor TR18 is turned on by an outputted control signal to interrupt the base bias of a power source regulating TR22. Thereby, the power source of the tape recorded with the broadcasting radio receiver is interrupted and a sleep operation synchronizing with the completion of a broadcasting can be performed.</p> |
