Patent ID: 7986110
Filing Date: 2011-07-26
Classification: H05B

Abstract:
1. A light source driving device for driving a light source comprising: a power stage circuit that converts an external electrical signal to an alternating current (AC) signal; a transformer circuit connected between the power stage circuit and the light source, that converts the AC signal to a high voltage electrical signal adapted for driving the light source; a fault detecting circuit that detects whether the light source is nonfunctional and outputs a fault signal upon the condition that the light source is nonfunctional, the fault detecting circuit comprising: a voltage level comparison circuit having a first input to receive a lamp status feedback signal, a second input, and an output to output the fault signal; and a variable-benchmark voltage circuit connected to the second input of the voltage level comparison circuit to provide a variable-benchmark voltage signal according to a lamp brightness control signal and a surrounding temperature of the light source; and a control circuit connected between the fault detecting circuit and the power stage circuit, to output a control signal to the power stage circuit based on the fault signal.