Self excited half-bridge series resonant parallel loaded fluorescent lamp electronic ballasts

Time-domain analyses are given for the electronic ballasts adapted from a self excited half-bridge series resonant parallel loaded inverter operating in either high quality factor (>2.5) or low quality factor (≈1.0) conditions. The operational principles of the inverter applied as an electronic ballast are described in detail from which the voltage and current stresses imposed on switching devices can be determined analytically, and a systematic design procedure can be, therefore, outlined. In addition, practical considerations taking into account the storage time of the switching devices and the nonlinear characteristics of the saturable core are addressed. The computer simulations and experimental results from a laboratorial prototype are used to verify the theoretical predictions and discussions