To provide a method for controlling an energy saving of a LED light enhancing its momentum of recent rapid spread in terms of an energy saving and an useful life, for instance, selling of the LED light started at major lighting apparatus manufacturers, which adjusts a brightness by itself in response to an ambient brightness, in which a driving current of the LED light is needed to be controlled by precise detection of the ambient brightness without being influenced by an adjacent LED light.

In an energy saving LED light, a DC output obtained from an AC current through a PFC circuit, comprising a pressure rising chopper circuit in which a rectification circuit is combined with a switch and an inductor, is lead to an LED circuit by connecting a switching circuit in series, and a magnitude of the DC current is controlled by the switch of the PFC circuit as to detect the ambient brightness and make the LED in a needed brightness, while an AC power supply voltage waveform is near a zero-voltage and a series switch connected to the LED is being switched off.