| 摘要 |
PURPOSE:To eliminate an AC component included in a DC control voltage and also to prevent oscillation in a control loop by applying the DC control voltage to an element to be controlled by way of a sample holding circuit. CONSTITUTION:A detected voltage from output terminal 7 is rectified, amplified by DC amplifyung circuit 9 and then applied to sample holding circuit 11 via low- pass filter 10. Sample holding circuit 11 performs sample holding operation by sampling pulses of several Hz from low frequency oscillator 12. The output of sample holding circuit 11 is applied to the stage to be controlled via low-pass filter 14. Low-pass filters 10 and 14 can obtain signals, having disused AC components eliminated sufficiently, as control voltages even if the bands are not narrowed, so that abnormal oscillation in the contol loop can be prevented. |
