Patent ID: 8129923
Filing Date: 2012-03-06
Classification: H05B,Y02B

Abstract:
1. A switching circuit adapted in an LED circuit comprising: a voltage-trimming module to generate a reference voltage; a mode-selecting circuit comprising: a voltage-dividing module to receive and linearly divide a reference voltage to further generate a working voltage; and a switch connected to the voltage-dividing module, wherein the switch has an output; a comparator comprising a first input connected to the switch, a second input and a comparator output; and a control module; wherein during a measuring mode, the switch transfers the reference voltage and the second input of the comparator is connected to the comparator output, such that the reference voltage is measured at the comparator output for the voltage-trimming module to adjust the reference voltage according to the measured result; during a working mode, the switch transfers the working voltage, the second input of the comparator receives an output voltage of the LED circuit and the control module generates a control signal according to the voltage of the comparator output to switch the LED circuit.