PURPOSE: In an ozonizer using silent discharge, to enable extreme miniaturization and price reduction of ozonizer, by applying a chopping circuit and a high-tension coil to it.

CONSTITUTION: Commercial electric source is converted into a stable DC voltage source by the rectifier 12 and the smoothing condenser 13. The primary winding 18a-18b of the high-tension coil 18 is connected to the collector and emitter of the switching transistor 17 in series, and an ozonizer is connected to the secondary winding 18c-18d. The reference pulse 19 is generated in the oscillation circuit 15 depending upon the signal from the set terminal 14, the limited pulse 20 is made by the pulse circuit 16, and fed as base current for the transistor 17. The transistor 17 is in a continuity state only when the base current is applied, and current is sent to the primary winding 18a-18b. When the base current is broken, the energy 1/2LI2 of the primary coil L is fed to the secondary coil 18c- 18d and the ozonizer connected to it. Ozone is generated by making the peak voltage of the secondary voltage ≥ twice discharge voltage of the space of the ozonizer.