Patent ID: 8487552

Claim:
A lighting apparatus comprising: a light emitting diode (LED) module; a heat sink configured to emit heat from the LED module; a rectifier configured to rectify an input alternative current (AC) power; a transformer including a first coil and a second coil to transform the rectified power; an electronic module configured to bias a current for operating the LED module based on an input power transformed from the second coil; a switching circuit configured to repeat on and off based on a predetermined frequency and a duty ratio and adjust a duty ratio; and a damper part configured to decrease the output based on the input voltage automatically, wherein the electronic module biases the current to be varied in reverse proportion to the AC input power, and wherein, when the AC input voltage is lowered, the lighting apparatus sets and controls an on-time of the switching circuit to be reduced below a range in which interruption of AC line currents is not generated and controls to lower the output of the damper part to be connected to a rower line after the rectifying with a ground.