Influence of the use of square waveforms in fluorescent lamps

This paper describes the effects of applying square waveforms to the fluorescent lamps. In this work the additional benefits of using square waves and their effects in the luminous efficacy, power factor and crest factor for different power levels are presented. The study was realized by varying switching frequency in a wide range and it showed that the efficacy in the lamp fed with square waveforms remains almost constant and higher than the efficacy obtained with sinusoidal waveforms. On the other side, power factor and crest factor were almost unitary in all the frequency range. The employment of square waveforms in low or high frequency presents an advantage against sinusoidal waveforms. The obtained results suggest the possibility to employ square waveforms in lighting sources where efficacy is critical, like emergency lighting sources.