| 摘要 |
PURPOSE:To eliminate the probability of a rush current running by power source short circuit by constituting a resonance circuit in such a manner as sending a current of lag phase to an inverter load even when operated at the switching frequency of lighting time in the no-load state and operated at the switching frequency of no-load time in the lighting state. CONSTITUTION:The resonance frequency f1 of series resonance circuits L1, C1, the resonance frequency f2 of parallel resonance circuits L2, C2, and the higher f3 of resonance frequencies of a resonance circuit formed of the series resonance circuits L1, C1 and the parallel resonance circuits L2, C2 are set to f1<f2<f3. The switching frequency fA of no-load time and the switching frequency fB of lighting time are bet to fA>f2 and f1<fB<f2. Thus, a current of lag phase is sent to an inverter load even when the resonance circuit is operated at the switching frequency fB of lighting time in no-load state and operated at the switching frequency fA of no-load time in the lighting state. Hence, even if an error judgment of no-load state and lighting state occurs, there is no possibility of a rush current by power source short circuit. |
