Abstract - Correction of lower harmonics of the cyclotron magnetic field is of great importance for its operation. Error in the magnetic field lower harmonics can reduce the efficiency of the beam extraction. For control of the cyclotron magnetic field lower harmonics, the so called inner and outer harmonic coils are provided. These harmonic coils must be fed by a very high accuracy current source power supply. This power supply must be equipped with a high resolution measurement and control scheme. Harmonic coils are supplied with conventional thyristor controlled converters with analog control strategy. Frequent interruption of operation and difficulties in the adjustment of harmonic coil current lead to economical and research - time losses. This research project aims to replace this conventional system with a more effective, accurate and less complicated digital control system based on Motorola DSP56F807 and high switching frequency power circuit.