| 摘要 |
PURPOSE:To reduce the power loss of a servo-circuit, by detecting the rotational frequency of a motor driven by the output voltage of a DC-DC converter, feedbacking the detection signal to the servo-circuit and controlling the output voltage of the converter by an error signal of the servo-circuit. CONSTITUTION:The voltage of a battery 1 is changed into an AC voltage depending on a control signal S1 applied to the control input terminal 11 of a transistor 8. The AC voltage is supplied to a rectifier 9 through a transformer 7. The output voltage of the rectifier is smoothed by a capacitor 10. A DC voltage S3 is thus applied to the motor 3. The rotational frequency n of the motor 3 is detected by a detector 6 and feedback to the servo-circuit 4. The error signal S2 is supplied from the servo-circuit 4 to a voltage-frequency converter 5 so that a pulse of duty factor corresponding to the error signal S2 is applied to the input terminal 11 of the transistor 8. The output voltage of the DC-DC converter 2 is thus controlled. Since the motor 3 is driven without using a motor driving stage, the power loss is reduced. |
