APPARATUS FOR REDUCING HARMONIC

摘要

PURPOSE: An apparatus for reducing harmonic waves is provided to compare a modulation index of an input switching signal with a set modulation index, thereby applying a space dither delta modulation method or a time dither delta modulation method based on the comparison result. CONSTITUTION: A space dither sigma delta modulation unit(20) reduces harmonic waves due to an input switching signal using a space dither sigma delta modulation method. A time dither sigma delta modulation unit(30) reduces harmonic waves due to the input switching signal using a time space dithered sigma delta modulation method. A modulation method selecting unit(10) transmits the input switching signal to the space dither sigma delta modulation unit or the time dither sigma delta modulation unit based on a comparison result between a modulation index of the input switching signal and a set modulation index.