Patent ID: 8664877
Filing Date: 2014-03-04
Classification: H05B

Abstract:
1. A light driving apparatus, comprising: a rectifier circuit for rectifying a full wave output from a power source; a transformer circuit for converting a magnitude of the voltage output from the rectifier circuit and outputting the converted voltage; a power factor correction circuit for detecting a load size by using a feedback voltage, and adjusting the output voltage of the transformer circuit according to the detected load size to compensate a power factor of the power source; a smoothing circuit for smoothing the voltage output from the transformer circuit, outputting the smoothed voltage, and supplying the output voltage to an LED module; a constant-current driving circuit for controlling an LED current so that a constant driving current flows through the LED module; a dimming control circuit for controlling the constant-current driving circuit to adjust a current flow of the LED module so that dimming is controlled; a photo-coupler for applying the feedback voltage to the power factor correction circuit; a sample and hold circuit operated according to the control of the dimming control circuit to maintain a consistent output voltage; a first photo-coupler driving circuit for feeding back the voltage output from the sample and hold circuit and applying the feedback voltage as a driving voltage of the photo-coupler; and a second photo-coupler driving circuit for feeding back the voltage output from the smoothing circuit and supplied to the LED module, and supplying the feedback voltage as a driving voltage of the photo-coupler.