| 摘要 |
PROBLEM TO BE SOLVED: To obtain a multichannel inverter by which a plurality of discharge tubes can be turned on simultaneously, without generating flickers and whose shape can be reduced as a whole so as to be lightweight and to easily turn on the discharge tubes by the inverter. SOLUTION: A plurality of resonance power supply circuits RS1 to RS4 which are constituted respectively of step-up transformers, resonance capacitors and switching transistors are provided. The transistors are driven near the resonance frequency of the resonance power supply circuits. All inverters 10 to 13 are driven at the same timing. A plurality of discharge tubes DS1 to DS4 on the secondary side of the step-up transformers in the resonance power supply circuits RS1 to RS4 are turned on by high-frequency voltages at the same frequency. When the inverters 10 to 13 are started, they are driven in a short time at a frequency which is lower than the resonance frequency by taking into consideration that the discharge tubes are easily turned on. When the discharge tubes are abnormal, the turning-on operations of all the discharge tubes are stopped by using the output of an OR circuit as the abnormal signal of every discharge tube. |
