摘要 |
In an electric power apparatus with a voltage stepdown active filter circuit, the on-period of a switching transistor is shortened only during the period near at the phase while a commercial input voltage takes a peak value to perform a constant current control for making the current flowing through the transistor constant, and at the other phase, a constant voltage control is performed to make the rectified voltage constant. It is therefore possible to prevent a low efficiency of the electric power apparatus to be otherwise caused by a complicated circuit structure of the apparatus, a bulky size of the apparatus, an increase of noises, and a large cost. <IMAGE> |