Switching method and apparatus for increasing efficiency of an inductive load and switching means supplying the load

A switching method for increasing an efficiency of an inductive load and switching means, said switching means including a switching device and supplying the load, from a D.C. voltage E, with a resulting voltage, said method comprising the steps of:

• switching said switching device according to a high frequency PWM process for connecting said D.C. voltage E to terminals of the inductive load during a first part of each half period T/2 and for creating a rising low frequency contribution UmLF which rises from 0V to a maximum value of the D.C. voltage E;
• maintaining the D.C. voltage E connected to the terminals of the inductive load for at least a sixth of the period T/6 during each said half period T/2, said maintaining step creating a plateau in said low frequency contribution with the maximum value of the D.C. voltage E applied to the terminals of the inductive load;
• and
• switching said switching device according to a high-frequency PWM process for connecting said D.C. voltage E to the terminals of the inductive load during a remaining part of each said half period T/2 and for creating a declining low frequency contribution UmLF which declines from said maximum value of the D.C. voltage E to 0V.