Patent ID: 8335093

Claim:
A power-supply arrangement an explosion-proof configuration and galvanic isolation comprising: a power-supply input, a transformer that has a primary winding and a secondary winding separated galvanically from this primary winding, a controlled semiconductor switch that has at least one control input and that forms, with the primary winding, a series circuit that lies parallel to the power-supply input, a controllable control circuit for the semiconductor switch that delivers, for the semiconductor switch, a periodic control signal that is controlled such that the output voltage on the secondary winding and/or the current through this winding corresponds to a specified desired value, and a current limiting device that has a capacitor lying parallel to the semiconductor switch and a voltage monitoring circuit that lies parallel, on the input side, to the capacitor and whose output signal acts on the switch state of the semiconductor switch such that the semiconductor switch is moved to a stationary state in which it generates no alternating current through the primary winding when the voltage on the capacitor exceeds a predetermined limiting value.