POWER-SUPPLY DEVICE FOR TURNING ON LAMP

摘要

PROBLEM TO BE SOLVED: To provide an economical power supply for lighting lamp which supplies both the heater voltage of a magnetron and high voltage by a single transformer in an electrodes visible light-emitting lamp system using a magnetron. SOLUTION: Both heater voltage and high voltage are supplied by a fly-back converter composed of one single transformer L1. During a pre-heating period, the switching frequency of a fly-back converter is fixed to be a frequency at which high voltage current of a magnetron scarcely flows through a switching frequency controlling circuit CTRL2.