Method for the automatic adjustment of the commutation angle of brushless DC motors

Actual rotary speed (omega ) of the motor is measured. This is compared with a previously-determined and stored rotary speed (omega old, alpha ). The commutation angle (alpha ) is increased by a given value delta alpha , should omega exceed omega old, alpha . Alternatively it is decreased by delta alpha , should omega old, alpha exceed omega . The actual rotary speed omega is stored as a new value of (omega old, alpha ). The angle of commutation alpha is variable between lower (alpha min) and upper (alpha max) limits. Variation is only carried out during stable operation. Motor efficiency is optimized without measuring power taken, i.e. the actual voltage and current consumed. An independent claim is included for corresponding equipment adjusting the commutation angle, using an open control circuit.