METHOD AND APPARATUS FOR DETECTING A PHASE OF INPUT POWER

摘要

The disclosed embodiments of the present invention relate to a method and an apparatus for detecting a phase of input power. According to a disclosed embodiment of the present invention, a phase detection apparatus comprises: an AC input unit to which the input power is applied; a zero-cross generation unit which outputs a zero-cross signal at a zero-cross time point of the input power by using a photo coupler; and a zero-cross detection unit which converts the zero-cross signal into a pulse signal and detects the phase of the input power through the pulse signal. A compensation capacitor is connected in parallel to a primary side of the photo coupler.