The Influence of the Startup Process of Small Metal-Halide (MH) Lamps on Electronic Ballast Design

In this paper, the authors present the results of an investigation into the starting process of a small wattage metal halide lamp and address the influence of the starting process, at extra- high frequency (>350 kHz), upon the performance of two most commonly used electronic ballast circuit topologies, namely the LCC resonant inverter and LCL resonant inverter. The starting transient processes driven by both ballast systems are captured, analyzed and explained. It has been found that the starting process could affect the operating performance of an LCL ballast and may destroy its power switches in the worst case while a LCC ballast gets the advantage over the LCL ballast for the stability during the transient starting process.