Patent ID: 8148918

Claim:
A light source driving device, for driving a plurality of light sources, comprising: a Power Factor Correction (PFC) circuit that converts a received electrical signal to a direct current (DC) signal; a DC/AC converting circuit connected to an output of the PFC circuit for converting the DC signal to an AC signal; a transformer circuit connected to the DC/AC converting circuit for isolating the AC signal output from the DC/AC converting circuit; a resonance balancing circuit connected to the transformer circuit for converting the isolated AC signal to another AC signal capable of driving the plurality of light sources; a PWM dimming controller connected to the DC/AC converting circuit for outputting a control signal to control output of the DC/AC converting circuit according to a received dimming signal, wherein duty cycle of the control signal is fixed; a voltage dividing circuit connected between the output of the PFC circuit and ground for adjustably dividing voltage of the DC signal output from the PFC circuit, and outputting a divided voltage signal; and a PFC controller for feeding the divided voltage signal back to the PFC circuit to control the DC signal output from the PFC circuit.