| 摘要 |
PURPOSE:To control a payout side reel to a specified rotational frequency without refernece to whether a load is large or small, by detecting the driving voltage and counter electromotive voltage of a take-up side and a payout side motor, and controlling the driving voltage to the take-up side motor on the basis of the output of comparison with a reference voltage and amplification. CONSTITUTION:A tape recorder which has DC motors M1 and M2 for driving a take-up and a payout reels, a take-up direction changeover switch 13, and a buffer amplifier 10 are provided with amplifiers 11 and 12. The amplifier 11 detects and compares the vounter electromotive voltage of the payout motor and the driving voltage VD of the take-up motor with reference voltages VR1 and VR2 respectively, and then supplies the result to the amplifier 10, thereby controlling the driving voltage VD of the take-up motor by the motor. Thus, the rotational frequency of the payout reel is controlled to a specified adequate vaue without reference to whether a load is large or small. |
