At present there are no commercially available compact fluorescent lamps that can be dimmed by ordinary Triac dimmers from 100% to less than 3% of the lamp power. Two conditions have to be satisfied in order to use Triac dimmers to control the light intensity of fluorescent lamps with a very wide dimming range from 100% to about 3%. The first condition is that the Triac, that consists of two SCR thyristors in anti-parallel configuration, must be able to operate in a stable manner for a wide range of firing angle. The second condition is that the dimming method must be able to control the lamp power down to low level. Existing techniques can achieve dimming range from 100% to about 20% to 30%, and to date no commercially viable techniques have been developed to extend the dimming range down to around 3%.
USPTO Backgrounds
USPTO Backgrounds