Abstract: A high-frequency, switching-type protected power supply, in particular for electrostatic precipitators, characterized by the fact of comprising a regulated power supply system for providing direct voltage adjusted at a desired value and at a relatively low voltage; a high efficiency, high-frequency switching system driving a step-up voltage transformer until reaching substantially the desired operating voltage of the precipitator, the secondary circuit of which directly feeds, by means of a rectifier group, the electrostatic precipitator. The high-frequency switching system is controlled in its operation in response to abnormalities indicating an incipient discharge between the electrodes of the electrostatic precipitator to modify the operating conditions in order to avoid the formation of disruptive discharges with consequent possible damage to the entire power supply and/or electrostatic precipitator.