The power supply unit PSB 1203 (TU U 30.0-30425613-010:2014; permission to applying of Ukraine №0957.14.12) converts unstabilized DC voltage from 175 … 345 VDC range into the stabilized 24 VDC voltage with battery backup, galvanic isolated from the primary power supply in high humidity conditions. A typical application - power supply to "DVC - Dnipro" equipment transceivers installed in the mine electric locomotives. The maximum load current is 3 A.