Gas discharge lamp controller

A method of controlling a discharge lamp at plural illumination brightesses, comprising:

• storing a current value and a voltage value for each of plural selected discharge currents and discharge voltages, respectively;
• and
• generating a selected discharge current and a separately controllable selected discharge voltage from stored current and voltage values and applying the selected discharge current and the selected discharge voltage to the discharge lamp for each of the plural illumination brightesses.

In a combination gas discharge lamp and gas discharge lamp controller that provide a range of illumination brightnesses, the improvement comprising:

• a dimming ratio between maximum and minimum flicker-free bightnesses of more than 20,000:1.

In a gas discharge lamp controller for controlling a gas discharge lamp, plural discharge current control signals for providing plural discharge currents to illuminate the gas discharge lamp at plural illumination brightnesses, each of the signals comprising:

• a discharge current pulse of a pulse period;
• and
• a duty cycle that cooperates with the pulse period of the discharge current pulse to provide a discharge current for a selected illumination brightness.