DISCHARGE LAMP LIGHTING DEVICE AND ILLUMINATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device in which electric power loss is reduced while the control action is made stable. SOLUTION: A boost chopper circuit 14 and an inverter circuit 15 are connected with a commercial alternating-current power supply (e) via a full wave rectification circuit 12. In order to make a lamp current of a fluorescent lamp FL constant, the output voltage of the boost chopper circuit 14 is controlled by an integrator 25. The lowest pole frequency of the integrator 25 of the control circuit 21 is set higher than the lowest pole frequency of the whole loop transfer function of the discharge lamp lighting device 5. The response in the vicinity of the lowest pole frequency of the loop transfer function is taken as the primary delay, and the turn round of the phase is made smaller and the phase margin is made larger, thereby the action is made to be stabilized.