Design procedure for resonant components of fluorescent lamps electronic ballast based on lamp model

A design method for half-bridge series-parallel resonant inverters suitable for driving various fluorescent lamps is introduced. The proposed steady-state circuit analysis is specially concerned with the second-order high frequency equivalent model of fluorescent lamps. To ensure zero-voltage-switching, the IR2151-driven power stage is set to operate above the resonant frequency. A design example are presented for a 40 W fluorescent lamp operating at a 30 kHz switching frequency and 110 V-RMS utility line voltage. Quasi-sinusoidal waveforms are obtained and the crest factor of lamp current is smaller than 1.7, resulting in longer lamp life. Lamps of various powers and brands are tested. All show good performance, verifying the functionality of the proposed procedure.