Abstract: An improved dynamic range dimmer for gas discharge lamps is provided in which the frequency is shifted during the startup of the lamp, and the frequency is shifted and the duty cycle is varied to dim the light emitted by the lamp. When dimming is desired the frequency is shifted to increase the voltage available to the lamp, which then has its power reduced by controlling its duty cycle. Such an arrangement provides a greater range of light intensity variation. If the lamp is turned off while set to a dimmed level, then the frequency is automatically restored to the resonant value used when starting the lamp, to assure breakdown of the plasma in the lamp for proper ignition.