| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device which makes the circuit efficiency improve. SOLUTION: An AC input terminal of a full-wave rectifying circuit 12 is connected to a commercial AC power source e via a filter circuit 11, and a capacitor C2 is connected between DC output terminals. A constant current choke L1, a first transistor Q1, a second transistor Q2, and a constant current choke L2 are connected to the capacitor C2, and the constant current chokes L1 and L2 are coupled magnetically with each other. The series circuit a load 16 and a capacitor c3 is connected in parallel with the second transistor Q2 and the constant current choke L2. For the load 16, the primary winding Tr2a of an insulating transistor Tr2 is connected between the junction between the first and second transistors Q1 and Q2, and a capacitor C4 for voltage resonance is connected in parallel with it. A fluorescent lamp FL1 is connected to the secondary winding Tr2b of the insulating transformer Tr2, and a capacitor C5 for start is connected between the other ends. A capacitor V6 which is to serve as a current path is connected between the insulating transformer Tr2 and an AC input terminal. |
