| 摘要 |
PURPOSE:To attain power saving and low heat dissipation by providing a switching circuit connecting/disconnecting a power supply of a recording and reproducing circuit and a retriggerable one-shot circuit controlling the switching circuit into off-state while a correct reproduced output signal is not obtained. CONSTITUTION:When an 'H' level output of the on-shot IC 12a is given to inverters 12b, 12c, the level is inverted into 'L' level and fed to a base of switching transistors (TRs) 11a, 11b, then the TRs 11a, 11b are turned off to cut off power application to a recording and reproducing circuit 3. In this case, the retriggerable one-shot circuit 12 is activated for an unstable time which is the subtraction of (Ts-Tc) from the unstable time of the reproduced output signal E0. When the positioning of a magnetic head 2 is stable, the stable reproduced output signal E0 is obtained. The currents IVcc1, IVcc2 flowing to the recording and reproducing controller are decreased by cutting off the power supply voltages Vcc1, Vcc2 fed to the circuit 3 while the E0 is unstable.
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