| 摘要 |
PURPOSE:To miniaturize a step-up transformer by using a secondary side circuit as the feeder circuit of high frequency and employing parasitic capacitance as a part of a resonance circuit constituted between an inductive ballast and the inductive output of a leakage flux type transformer. CONSTITUTION:A ballast is used as a choke coil from a conventional capacitor in an equivalent circuit, and the choke coil 2 of the secondary side circuit of a step-up transformer 1 has the effect of current limitation while a series resonance circuit is constituted with a parasitic capacitance 4 generated around a discharge tube 3, thus supplying the discharge tube 3 with high voltage. When the parasitic capacitance 4 generated around the discharge tube 3 does not reach the calculated value of series resonance at that time, an auxiliary capacitance 5 is added in parallel, thus adjusting resonance frequency. Accordingly, the parasitic capacitance is utilized as a part of the resonance circuit, thus adopting driving frequency higher than a conventional device, then miniaturizing the step-up transformer. |
