Push-pull type of high-frequency inverter with voltage controllability by using short-circuit mode and its application to high-frequency lighting circuit of electric-discharge lamp

The operating frequency of the inverter based on the resonant performance is fixed at the resonant frequency. Then, it is difficult to regulate the output voltage because the switch-on and -off time can not be set in an arbitrary manner. Therefore, the authors propose the control method of active use of the short-circuit mode to the voltage resonant type of push-pull high-frequency inverter circuit. The characteristics of the proposed inverter are carried out with analytical and experimental manner. The results of the theoretical steady-state analysis agree well with those in the experiment. The circuit efficiency is more than 90% in the wide control range. Further, the inverter is applied to the lighting circuit of electric-discharge lamp. In the lighting circuit made on an experimental basis, the wide range of output control from 83 V to 113 V of the supply voltage and the stable lighting of electric-discharge lamp can be achieved. Then, the circuit efficiency can be obtained over 88%. Thus, the proposed high-frequency inverter by using the short-circuit mode is proved to be of much practical use.