| 摘要 |
The circuit for recording audio signal only when the audio signal exists during intermittent speeches includes a comparator (3) comparing the output signal of an amplifier (1) with a reference voltage (Vref), a retriggerable monomulti (4) transmitting pulse signal according to the signals from comparator (3) and a record control terminal (REC), and a gate unit (5) controlling electron switch (SW1) which drives the switch only when the audio signal is transmitted from the amplifier (1). The output signal of the amplifier can be delayed by a delay circuit (6) so that the sound can be recorded after the speed of the tape becomes normal.
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