Power supply circuit device for a high intensity discharge lamp that

Abstract

This invention is to provide an inexpensive high intensity discharge lamp lighting device having a simplified circuit construction, which does not use a full-bridge mode inverter. The high intensity discharge lamp lighting device includes a rectifier for a power-frequency power supply, a booster chopper mode sine wave converter, a zero volt switching push pull inverter, and a high intensity lamp of a halide lamp. And, as a starting device for the halide lamp, the high intensity discharge lamp lighting device generates a high voltage (5 KV) using a resonance by a ballast choke for the inverter and a condenser connected in parallel to the halide lamp, thereby inducing a glow discharge. And, a PFM (pulse frequency modulation) circuit controls the lamp current of the halide lamp to keep it constant. And, when the AC power is turned off and turned on again, a re-lighting circuit after lighting works such that the control IC stops operation by a pulse-by-pulse mode current limiter of an inverter control IC, thereafter a soft starting circuit operates to generate a high voltage on the output of the inverter; when the lamp temperature is so high that the mercury vapor pressure inside the tube goes high and lighting cannot be started, the foregoing operation is repeated to achieve re-lighting.