The invention relates to an electronically commutated engine comprising a stator carrying several winding phases and a rotor. The individual winding phases can be controlled through final power stages over time-delayed periods divided into control times and dead times. To reduce power loss during the final power stages and, thus, to raise effectiveness, especially in the case of heavy currents, the invention provides for the control periods to be divided into an initial period and an end period. When the engine currents are low, clocking by pulse-width modulation occurs only during the initial or end periods, whereas, when currents are heavy, the current is fully switched through during the initial periods and additionally for a more or less long part of the end periods or during the end periods and additionally for a more or less long part of the initial periods.