Freely commutating chopper circuit

摘要

The invention relates to a chopper circuit with free commutation for the supply of power to a load from a source of direct current. It comprises a principal thyristor with a return diode, a series resonant circuit as the commutation circuit and a free-wheeling diode. The free-wheeling diode is parallel to the capacitor of the resonant circuit so that the coil serves both as the commutation circuit and the coil to limit variations of the current in the thyristor. The circuit is particularly suitable for use with electric traction motors.