Patent ID: 7333541

Claim:
A variable square-wave drive device for controlling a pair of square-wave drive signals having opposite phases, comprising: a power-supply unit for receiving an input voltage, and transmitting a necessary voltage to individual components; an oscillator for generating a clock pulse having a predetermined frequency; a frequency-divider/duty controller for receiving the clock pulse from the oscillator, frequency-dividing the clock pulse using predetermined frequency division rates, and generating a clock signal and a square-wave signal; a drive for receiving the square-wave signal from the frequency-divider/duty controller, amplifying the square-wave signal at an amplification rate determined by a bias voltage, generating first and second square-wave signals having opposite phases according to the amplified square-wave signal, and outputting the first and second square-wave signals as a pair of square-wave drive signals; a feedback controller for comparing a predetermined voltage variably determined by a user with the bias voltage of the drive, and generating a comparison result signal; a switching controller for generating a switching signal according to the comparison result signal received from the feedback controller; and a bias voltage regulator for charging/discharging the input voltage of the drive according to the switching signal of the switching controller, and regulating the bias voltage of the driver by charging/discharging the input voltage.