Patent ID: 7479738

Claim:
A drive circuit for light emitting diode (LED), connecting a power and driving a plurality of LEDs to emit light, wherein the LEDs are connected into a plurality of LED strings, the drive circuit comprising: a power converter, connecting the power and converting into a driving voltage provided to the LED strings; a detection circuit, electrically coupled to the LED strings and having at least a reference voltage, wherein the detection circuit detects a string voltage of the LED strings respectively and compares the string voltage with the reference voltage, so as to output a detection signal; and a report circuit, electrically coupled to the detection circuit and the power converter for receiving the detection signal and outputting a control signal to the power converter, wherein the power converter receives the control signal and adjusts the driving voltage according to the control signal, wherein the detection circuit has a plurality of the reference voltages, and the reference voltages are corresponding to the LED strings, so as to compare with the string voltage of the detected LED string respectively.