Electronic Ballast with Multi-phase Outputs for Fluorescent Lighting

Based on the experimental results and theoretical prediction, an electronic ballast with balanced multi-phase outputs is designed and built to reduce the variation in the light output of fluorescent lamps. While using a light detection circuit with photo-transistor to measure the light fluctuation, the results show that the waveform of light output variation is very similar to that of the lamp power. This implies that, with a balanced multi-phase operation, the resultant light output from lamps' multi-phase powers can be a constant. A three-phase electronic ballast circuit is built to verify this theoretical prediction. Experimental tests demonstrate that the light fluctuations can be effectively reduced by operating the lamps with currents of balanced multiple phases.