Active filter

Power factor correction circuit that cancels harmonic components of the current by switching a small passive element (coil) with an active element to improve the power factor. Unlike the other power factor correction circuit, the passive filter, it does not have disadvantages such as "bulky size", "narrow input current range and input voltage range", "cannot achieve a power factor of 0.9 or higher", and "difficult design", and since it can be made compact, it has become the mainstream power factor correction circuit.