Patent ID: 8441814

Claim:
An explosion-proof power-supply with galvanic isolation comprising: a power-supply input, a transformer that has a primary winding and a secondary winding separated galvanically from the primary winding, each of the primary and secondary windings having respective un-dotted end that is connected to a respective anode of a respective diode, each of the primary and secondary windings being further connected in parallel with a respective capacitor such that a voltage established in the respective capacitor associated with the primary winding is proportional to a voltage established in the respective capacitor associated with the secondary 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 and that selectively enables current flow through the primary winding of the transformer, a voltage sensing circuitry disposed to sense the voltage established in the respective capacitor that is associated with the primary winding, and an oscillator for controlling the semiconductor switch, wherein the oscillator has a control input into which a control signal is led from the voltage sensing circuitry such that the oscillator delivers to the semiconductor switch a pulse such that a voltage on the secondary winding and/or a current through the secondary winding is held at a specified desired value when the voltage established in the respective capacitor associated with the primary winding, as sensed by the voltage sensing circuitry, exceeds a predetermined value, wherein the control signal for the oscillator is derived from a voltage on the primary winding.