| 摘要 |
PURPOSE:To facilitate running control by inputting output of a frequency multiplying means and comparing means and switching the third switching means in synchronism with a head switching signal so as to output the first or the second switching means of large envelope as a slow-motion reproduction signal. CONSTITUTION:At the time of slow-motion reproduction, a controlling signal inputted to an input terminal 31 becomes H, and a switch 30 is switched to (a) side, and switches 7, 9 are changed synchronously to (a) side and (b) side by a head switching signal 8. An envelope read out by magnetic heads 1, 3 and amplified by an amplifier 11 is detected and inputted to the positive terminal of a comparator 27. On the other hand, an envelope read out by magnetic heads 2, 4 and amplified by an amplifier 10 is detected and inputted to the negative terminal of the comparator 27, when the former is larger, a signal H is outputted. The head switching signal 8 is inputted and inversely inputted to T-type flip-flop 14, 17 and a 2-multiplied signal is outputted from an OR circuit 20. A switch 12 is switched in synchronism with the head switching signal 8 immediately after the reproduction output is compared through D-type flip-flops 28, 29, and reproduced signals of large envelope are outputted from a terminal 13.
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