Abstract: The invention relates to static converters of the symmetrical type whose function is to convert an input direct current voltage into an output alternating current voltage of chosen frequency and power. The self-oscillator according to the invention is composed of two transistors mounted with a common emitter. The device is energized, for instance, from a main power supply unit, associated with a voltage limiter circuit, which subjects the output power of the device to any parameter. The capacitive power factor of the device is compensated by an inductance connected in series with the main power supply. The device according to the invention can replace, advantageously, the conventional "ballast" for fluorescent lamps.