High-intensity discharge lamp ballast and method for operating high-intensity discharge lamp

摘要

A high-intensity discharge lamp ballast includes a lamp operation unit configured to supply power from a power source to a high-intensity discharge lamp, a lamp voltage detector configured to detect a voltage applied to the high-intensity discharge lamp, a lamp status determination unit configured to determine whether the high-intensity discharge lamp is in a turned-on state, based on the voltage detected by the lamp voltage detector, an auxiliary lamp switching element configured to connect the power source and an auxiliary lamp having a rated voltage, and a controller configured to control the auxiliary lamp switching element so as to apply to the auxiliary lamp a voltage substantially equal to the rated voltage of the auxiliary lamp when the high-intensity discharge lamp is supplied with the power and the lamp status determination unit determines that the high-intensity discharge lamp is not in the turned-on state.