| 摘要 |
<p>PURPOSE:To automatically discriminate and switch a tape speed, by setting the frequency of an AC bias signal as a fixed frequency with high accuracy, providing a means which discriminates the frequency in a reproduction time, and switching the rotating speed of a motor. CONSTITUTION:The output of an oscillator 12 which oscillates the frequency with high accuracy is amplified at an amplifier 13, and is added on the output of a sound amplifier 2, and is supplied to a sound recording and reproducing head 41, then a sound recorded. In the reproduction time, a sound recording and reproducing switch 14 is switched, and the output of the sound recording and reproducing head 41 is amplified at an amplifier 21, and is reproduced as the sound with a speaker 22. The rotating speed of the motor can be switched in two stages from the outside, and when a switch 32 is switched to a manual operating side M, the rotating speed can be switched in two stages by turning on or off a switch 33, and when the switch 32 is switched to an automatic operating side A, it can be switched automatically in two stages by the output of a frequency discriminator 23. In this way, the discrimination and the switching of the tape speed can be performed automatically.</p> |
