HIGH VOLTAGE DISCHARGE LAMP LIGHTING DEVICE

摘要

A digital control circuit (16) synchronizes and controls the ON/OFF of semiconductor switching elements (Q11, Q12-Q15) of a step-down chopper (12) and an inverter circuit (13) and controls ON time for the semiconductor switching element (Q11) of the step-down chopper circuit (12) near the time of the reversal of polarity of an alternate waveform in the inverter circuit (13). Consequently, the overshoot/undershoot of the waveform of alternate current flowing in a high voltage discharge lamp is suppressed in a high voltage discharge lamp lighting device requiring rapid reversal of polarity.