Investigation of the Self-excited Step-up Type Inverter for a Fluorescent Lamp

Abstract

The operating characteristics of the self-excited step-up type inverter for a fluorescent lamp is investigated by simulation using input voltage of rectified 50Hz AC. The envelope curves of voltage and current waveforms of high-frequency oscillation with discharge load are calculated and compared with the measured curves. The obtained results are as follows.(1) Output voltages and currents of the inverter are a function of OFF-time of the switch in the circuit.(2) envelope curves of output voltage and current are proportionally modulated by the input voltage in the case of small input inductance and constant OFF-time.(3) Output envelope curves can be flattened by controlling the OFF-time via the input voltage.