Method for synchronizing commutated control circuits controlled by PWM control signals

A method for synchronizing at least one slave control circuit (1S), of switched type, controlled by a slave control signal (2S) having pulse width modulation exhibiting a slave period (3S) and controlling a slave load (4S), with a master control circuit (1M), of switched type, controlled by a master control signal (2M) having pulse width modulation exhibiting a master period (3M) and controlling a master load (4M), the method comprising the following steps:

• the master control circuit (1M) transmitting a synchronization signal (5) that is indicative of a master edge (67M, 68M) of an electrical quantity (7M, 8M) of the master circuit (1M);
• the slave control circuit (1S) receiving the synchronization signal (5);
• repeatedly measuring an interval (9SM) between a slave edge (67S, 68S) of the same electrical quantity (7S, 8S) of the slave circuit (1S) and the master edge (67M, 68M) of the electrical quantity (7M, 8M) of the master circuit (1M) as indicated by the synchronization signal (5), and time-shifting (92E, 92T) the slave control signal (2S) in a manner that decreases the measured interval (9SM), until said interval (9SM) is canceled out,
• wherein the direction of the master edge (67M, 68M) and the direction of the one or more slave edges (67S, 68S) of the measurement step are opposite.