DC high-current power supply with digital display of voltage and current. The voltage and current are continuously adjustable by means of coarse and fine controllers. The device can be used as a constant-voltage source with current limiting, or a constant-current source with voltage limiting. The selected operating mode is indicated by an LED on the front panel. Highly reliable even under extremely adverse conditions is ensured by automatic transformer switchover, MOSFET power amplifiers, and temperature-controlled fan speed with monitoring function. Air vents in the top and bottom and no external heat sink required. The output is protected against sustained short-circuits and a preset function for protecting against excess current and voltage is provided. An interface socket is located on the front panel with inputs and outputs for external programming and monitoring by a PC. A USB-analog interface adapter is available on request. Two or more such units can be operated in series or in parallel.