[en] To increase the efficiency of output of accelerated particles a system of high-voltage supply to the electrostatic deflector of the U-120 M cyclotron was developed. The peculiarity of the system is a possibility of a deep and smooth (90%) regulation of rectified voltage with its stability being preserved. To power the multiplying coloumn assembled using a single-cycle circuit on the 2 Ts 106 G small-dimensional rectifying posts and K15-4 condensers, a transistor converter and a step-up transformer of an original design on a disconnected ferrite core are used. To rise the transformation coefficient and to obtain voltage of a sinusoidal shape the frequency of the converter has been chosen to be equal to the frequency of succesive resonance of the transformer scattering induction with the input capacity of the coloumn. The stabilization system consisting of two rings of feedback permitted to combine deep smooth ragulation of rectified voltage and its stabilization with a high accuracy