Boost voltage converters are widely used in industry and engineering as power supplies and voltage stabilizers. The basis of the converter is a key element, with the help of which the redistribution of input energy to output energy is carried out, depending on the required transmission coefficient. The output voltage of the inverter depends on the input voltage and external load. Taking into account the switching nature of the converter, a robust relay control law has been developed in the article, which makes it possible to stabilize the output voltage at unknown load, when it is impossible to measure it.