The invention relates to a method and an apparatus for converting the energy of an energy storage (2) for operating an arc (6), wherein in order to convert energy, at least one switch (9) of a step-down converter is switched on and off in a controlled manner, wherein said at least one switch (9) is connected to the energy storage (2) at the input end. In order to be able to supply as much of the limited energy available from the energy store (2) to the arc (6), it is provided that a synchronous converter is used as the step-down converter for operating the arc (6), and that the at least one switch (9) of the synchronous converter that is designed as a power unit (3) is connected to a snubber circuit (10) at the output end such that at least the switch (9) is switched on and off in an snubbed state.