| 摘要 |
<p>PURPOSE:To quicken intermusic detection speed and to prevent surely intermusic detection mistake, by changing the time constant for intermusic detection in interlocking with the change of tape speed at reproduction. CONSTITUTION:When a magnetic head is located at the non-recording part between recordings, since the output signal is at low level, the output signal of an amplifier 2 is also at low level and a switching transistor 7 is interrupted. Since a time constant circuit T is connected to the collector of a transistor (TR)7, a base terminal voltage of a switching TR8 is gradually lowered with the time constant determined with a resistor 5 and a capacitor 61 and the TR8 is interrupted only when the base voltage is made lower than the cut-off level A. In response to this interruption, switching TRs 9 and 12 are conductive, a plunger 13 is operative, a driving mechanism (not shown) is operated to switch the state from the fast feed to the stop or reproduction and the intermusic detection is completed.</p> |
