| 摘要 |
PROBLEM TO BE SOLVED: To suitably control two DC/DC convertors. SOLUTION: In a discharge lamp lighting circuit 100, a first DC/DC converter CONV1 supplies, in an active state, a drive voltage to one end P1 of a discharge lamp 4. A second DC/DC converter CONV2 supplies, in an active state, the drive voltage to the other end P2 of the discharge lamp 4. A control circuit 10 supplies an AC drive voltage VL to the discharge lamp 4 by alternately setting the first DC/DC converter CONV1 in the active state and setting the second DC/DC converter CONV2 in the active state on a prescribed lighting cycle, and brings the average value of the output power of the first DC/DC converter CONV1 in the active state and the output power of the second DC/DC converter CONV2 in the active state closer to a prescribed target power by controlling the duty ratio of the on and off of the respective switching elements M1 and M2 of the first and second DC/DC converters CONV1 and CONV2. COPYRIGHT: (C)2010,JPO&INPIT |
