| 摘要 |
<p>PURPOSE:To make it possible to interchange the respective operations of a tape recorder with the use of the same solenoid by providing both a first drive circuit which is operated by rotation detecting means and a second drive circuit which is operated by a reproducing head. CONSTITUTION:In case detecting means including a rotation detector 1, an amplifier 2 and a rectifier 3 detects the interruption of a tape running operation, a first device circuit 5 is rendered conductive by the output of a comparator 4 to bias a solenoid SOL. When the signals on a tape are detected by a reproducing head H, a second drive circuit 10 is rendered inconductive by the detected output. As a result, a capacitor C1 is charged with the charges of the opposite polarity to the normal one. If, under this condition, the reprodued signals by the head H disappear, the second drive circuit 10 is rendered conductive. By the charges of the capacitor C1 which has been charged to have the opposite polarity, the first drive circuit 5 is rendered conductive to bias the solenoid SOL.</p> |
