| 摘要 |
PROBLEM TO BE SOLVED: To assure stable resonance operation synchronized with high frequency load current by integrating reciprocal current flowing through a power semiconductor device, discharging so as to reduce the integrated value according to an off period, and driving on or off according to the integrated value. SOLUTION: Power MOSFETs Q1, Q2 apply/remove control voltage to/from each gate, pass/shut off the current of a main power source 17, and give AC to a resonance load circuit of a resonance inductor Lr and a capacitor Cr between outputs O, N. Capacitors C1, C2 integrate reciprocal current flowing through the power MOSFETs Q1, Q2, and a discharge means 13, 14 reduce the integrated value according to an off period. Driving circuits 11, 12 make the power MOSFETs Q1, Q2 on and off according to the integrated value, and light a discharge tube 18 connected to the capacitor Cr in parallel. Cost of the driving circuit is reduced by using a low voltage-resistant IC, and the brightness of the discharge tube is varied by giving a light modulation signal. |
