A modulation driver of quasi-sinusoidal asymmetric current designed to feed an electrocoagulator is described. The device ensures specified parameters of the output current for a wide range of load resistances and frequencies. The rated load power is 2.5 kW, the output current has a quasi-sinusoidal asymmetric shape, the mean value of the current positive half-wave is 5–16 A, the degree of asymmetry of half-waves of opposite polarities is 6–11, the range of the sliding frequency control is 20–2000 Hz, and the frequency set-on accuracy is ±1 Hz. The device is fed from a 380 V+10 –15% and (50–60)-Hz three-phase main.