A Study of the Leakage Transformer Type Operating Circuit with Bypass Circuit for a Metal Halide Lamp

A bypass circuit is set up in the secondary winding of ballast for the leakage transformer type operating circuit for a metal halide lamp. It is shown from computer simulation and experiment that harmonic element containing rate of the power supply current wave form of the operating circuit can be controlled to be small by deciding optimal tap position of the bypass circuit and optimal values of circuit constants of the bypass circuit. It is shown from experiment that the power factor of power supply current is about 100% by setting up a capacitor for the power factor improvement in the arrangement at the input terminal of the operating circuit.