| 摘要 |
PURPOSE:To reduce the ripple of the output voltage of a DC chopper by inverting the polarity of the ripple of the input voltage of the DC chopper and applying only the ripple component thereof to the output side of voltage regulator. CONSTITUTION:A rectified voltage 3 from a power source voltage 52 is applied to a ripple voltage detector 72, a DC voltage 2 having different polarity to the DC component contained in the rectified voltage and corresponding to the DC component is applied to the detector 72, and the DC component is thus averaged to be zero. The output voltage 4 is added to the output voltage 1 of the DC chopper, and the sum is applied to a pulse width regulator 82, and the output signal 6 from the regulator 82 is applied to the base of a chopper transistor 56. Thsu, the output signal 6 is largely reduced in the input ripple frequency at the average value, and the ripple of the output voltage can be thus reduced. |
