| 摘要 |
PURPOSE:To accelerate the responding speed at a load varying time by providing a plurality of filters of different responding speeds and ripple reducing rates to an input signal, and sequentially outputting stepwisely the faster one of the responding speeds to slower one. CONSTITUTION:The output voltage Vt of a tachometer generator 4 is converted by a ripple reducing circuit 6 to a voltage Vt', and fed back to an addition point 1. The reducing circuit 6 has filter amplifiers 11-13 of different responding speeds and ripple reducing rates to an input signal, ripple reduction signals A-C are processed by subtractors 21, 22, adders 24, 26, and nonlinear circuits 23, 25 for eliminating the ripple in the normal state of the ripple reduction signal, and sequentially outputted stepwisely from the faster responding speed to slower speed. In this manner, the responding speed at the load varying time is accelerated, and the ripple in the normal state can be reduced. |
