The disclosure relates to an inverter comprising at least two controllable load thyristors which connect a load alternately with the poles of a feed d.c. voltage source. There is connected in parallel with each load thyristor one diode each which is a component of a commutation installation. The commutation installation manifests an LC-series oscillatory circuit dimensioned for a specified load current, and, manifests, for each load thyristor a controllable commutation thyristor which forms a closed circuit with the LC-series oscillatory circuit and its diode. The LC-series oscillatory circuit is connected to an auxiliary d.c. voltage source of a constant voltage via a reloading circuit.