Patent ID: 6570347
Filing Date: 2003-05-27
Classification: H05B,Y10S

Abstract:
A method of controlling the brightness of a gas-discharge lamp including a power supply, the power supply including a drive having first and second switches, the drive supplying a varying signal in response to control signals being provided to the first and second switches, the method comprising:establishing a repetition period; for a first interval of the repetition period, generating a first control signal having a first duty cycle and providing the first control signal to the first switch, and generating a second control signal having a second duty cycle and providing the second control signal to the second switch; for a second interval of the repetition period, generating a third control signal having a third duty cycle and providing the third control signal to the first switch, the third duty cycle being less than the first duty cycle, and generating a fourth control signal having a fourth duty cycle and providing the fourth control signal to the second switch, the fourth duty cycle being less than the second duty cycle; and repeating the repetition period, thereby controlling the brightness of the lamp.