ABSTRACT
ABSTRACT The aim of the research was to find out the effect of dimming on lamp life of T5 fluorescent lamps. The other goal was to find out the optimal cathode heating current in dimming use. In the research there were eight test groups and in each test group there were twenty-four T5 28 W fluorescent lamps from three different manufacturers. Test groups were burned undimmed (100 %) or dimmed to 15 % or 5 %. Cathode heating level was nominal (N), reduced (-) or increased (+). The results so far indicate that the cathode voltage with T5 28 W lamps should be more than 7 V and the cathode temperature more than 700° C. Results show that with proper cathode heating also T5 lamps can be dimmed without decreasing their lamp life.
