A supply system for a load with a parallel resonance and comprising a transformer having a first and a second primary winding and a secondary winding, the secondary winding being directly connected to the load, which is essentially equivalent to a capacitor and a resistor in parallel, and having the function of a parallel resonant inductance. The supply system comprises a switching block connected to the transformer and including a first and a second switch respectively connected to the first and second primary windings and having respective control terminals connected to a first and second output terminal of a driving device adapted for driving the first and second switches in a complementary manner for obtaining an output voltage on the secondary winding having a sinusoidal pattern and a value determined on the basis of the capacitive value of the load and of the inductive value of the secondary winding.