ELECTRIC DISCHARGE LAMP LIGHTING DEVICE

摘要

PURPOSE:To provide stable light output of an electric discharge lamp by carrying out output control of an inverter circuit according to fluctuation of voltage of a power supply and output control of an inverter circuit according to a light governing signal individually. CONSTITUTION:Switching of MOSFETQ1, Q2 of an inverter circuit is controlled by a driving control circuit 2. Voltage of A.C. power AC is detected by a power supply voltage detecting circuit 6. A frequency variable circuit 21 for controlling the switching frequency of MOSFETQ1 and Q2 according to the output of the power supply voltage detecting circuit 6 is provided in the driving control circuit 2. An on-duty variable circuit 22 for controlling on-duty of the MOSFETQ1 and Q2 according to a light governing signal S1 is provided.