Patent ID: 8125227

Claim:
A method for controlling a capacitive sensor in a vibrating mirror motor system comprising a capacitive sensor, a subtraction circuit and an adder circuit connected with the capacitive sensor, a high-frequency power supply for providing energy to the capacitive sensor, a digital-analog converter, and a digital gain stage adjuster having a digital potentiometer being connected to a microprocessor, wherein the method comprises: summing, by the adder circuit, values obtained by the capacitive sensor; comparing, in a comparison circuit, the summed values from the adder circuit with a target gain control value generated by the digital-analog converter; providing a gain adjustment value to the high-frequency power supply, said gain adjustment value based on the comparing; outputting a position signal by the digital gain stage adjuster after adjusting a value resulted from the subtraction circuit performing subtraction on values obtained at said capacitive sensor; and before outputting the position signal by the digital gain stage adjuster, setting a stage coefficient of the digital potentiometer by the microprocessor.