Patent ID: 7834602

Claim:
A feedback power control system for an electrical component that has first and second electrodes, and a work current flowing therethrough, said feedback power control system comprising: a multiplying unit having a first input terminal adapted for receiving a work voltage corresponding to a voltage drop between the first and second electrodes of the electrical component, a second input terminal adapted for receiving a feedback voltage corresponding to the work current flowing through the electrical component, and an output terminal for outputting a measuring voltage corresponding to a consumed power of the electrical component, a value of the measuring voltage being equal to a product of a value of the work voltage and a value of the feedback voltage; a control unit having a first input end coupled to said output terminal of said multiplying unit for receiving the measuring voltage therefrom, a second input end adapted for receiving a reference voltage, and an output end for outputting a control voltage corresponding to a voltage difference between the measuring voltage and the reference voltage; and a regulating unit providing the feedback voltage to said second input terminal of said multiplying unit, and including a series connection of a transistor and a resistor adapted to be coupled to the electrical component and providing the feedback voltage, and an amplifier having a first input end for receiving the feedback voltage from the series connection of said transistor and said resistor, a second input end coupled to said output end of said control unit for receiving the control voltage therefrom, and an output end coupled to said transistor for controlling operation of said transistor.