Corona discharge surface treater without high voltage transformer

A corona discharge generator for surface treatment without the use of a step-up transformer with a high-voltage secondary is presented. The oil bath for high-voltage components is eliminated and still a reasonable volume, efficiency, and reliability of the generator are obtained. The voltage multiplication is achieved by an LC series resonant circuit. The resonant circuit is driven by a bridge type voltage-source resonant inverter. First, feasibility of the proposed method is proved by calculations. Closed form design expressions for key components of the electronic generator are provided. Second, a prototype of the electronic generator is built and efficiency measurements are performed. For power measurement, Lissajous figures and direct averaging of the instantaneous voltage-current product are used. The overall efficiency achieved is in the range between 80% and 90%. Index Terms--Surface treatment, corona, gas discharges, highvoltage technique, resonant power conversion.