| 摘要 |
<p>PURPOSE:To stably drive a solenoid without boosting battery voltage by superposing the charging voltage of capacitors by the detection output at the high speed running of tape on the supply voltage and driving a program searching solenoid. CONSTITUTION:When a tape is high speed run for the purpose of program searching, switches S1, S2 are changed over to the contact b, and the detection output by a head H is not applied to a speaker SP and is applied to a solenoid driving circuit 2. This causes a capacitor C3 to be charged via capacitor C2, resistance R1, solenoid L by the DC voltage having been subjected to voltage doubler by the capacitor C1, diodes D1, D2 of the circuit 2. When there is no more program-searching detection output of the head H, the switches S1, S2 connect to the contact a, causing transistors Tr1, Tr2 forming a Schmitt circuit to conduct by way of a capacitor C5, etc. The supply voltage B superposed with the charging voltage of the capacitor C3 is then applied to the solenoid L, whereby the reproduction or stop state is set.</p> |
