FIELD: electrical engineering. SUBSTANCE: device has a voltage converter, alarm signal transducer, converter control unit, auxiliary generator, two shift registers and three flip-flops, as well as AND, OR circuits. In case of a disturbing influence the overcurrent transducer or one of the shift registers sends a signal to the flip-flops and to the interlocking input of the converter control unit. EFFECT: overcurrent protection, short-circuit protection of load and converter, as well as monitoring and protection against variation of the conversion frequency level. 2 cl, 2 dwg
