A lamp lighting system allows dimming of a compact gas discharge lamp to a
low light output level without perceptible flicker. When the system
receives a request to dim the lamp to the low level, the lamp is operated
at an intermediate output level prior to operating the lamp is then
requested low level. When the lamp cools to below a threshold
temperature, the lamp is then operated at the requested low level. In one
embodiment, the lamp is dimmed from its full rated output level to 1% of
its full rated output level. The intermediate level is approximately 2%
to 5% of this full rated level. No flicker is perceived when the lamp
level is reduced from the full rated level to the low level. Upon
cooling, no flicker and no change in output level are perceived when the
lamp is subsequently reduced from the intermediate level to the low
level.