Discharge-lamp illumination circuit

摘要

A discharge-lamp illumination circuit has a DC power supply circuit, a DC-AC conversion circuit, and a control circuit for controlling a voltage from the DC power supply circuit. The DC power supply circuit has a transformer and a first switching element connected in series with a primary coil of the transformer. The activation/deactivation of the first switching element is controlled by the control signal from the control circuit. The transformer is equipped with secondary coils equal in number with the discharge lamps. Each secondary coil is equipped with a second switching element whose activation or deactivation is controlled by a signal from the control circuit. The secondary coils provide different voltages by means of control of the second switching elements.