Abstract: The invention concerns a method for operating an electronically commutated motor (10) that is equipped with a current limiting arrangement which acts on a PWM controller (56). The latter, in operation, delivers PWM pulses (60) having a controllable pulse duty ratio (pwm) and a substantially constant frequency. In the event a predetermined upper limit value (Isoll; Iw) of the motor current (Iist) is exceeded, the current limiting arrangement effects a change in this pulse duty factor (pwm) in order to reduce the motor current (Iist). If the motor current (Iist) exceeds a predetermined upper limit value (Isoll; Iw) while the motor (10) is rotating, that limit value (Isoll; Iw) is raised by a timing member (260) during a predetermined time span (304) (FIG. 8: Iwmax), so that the available motor power is temporarily raised in the context of a load peak. If the rotor (24) is stalled, the limit value (Isoll) is not raised but instead is greatly lowered.

Abstract: An electronically commutated DC motor comprises a stator comprising at least one stator winding (22, 24, 26), a rotor (28) electromagnetically interacting with the stator, a positive and a negative DC voltage line (76, 78) for supplying power to the motor (20), in particular from a battery (77), a full bridge circuit (74) for controlling the current in the at least one stator winding (22, 24, 26), which full bridge circuit (74) comprises a plurality of bridge arms that each comprise an upper bridge transistor (66, 80, 86) for controlling the current from the positive DC voltage line (76) to an associated terminal (68; 82; 88) of that stator winding (22, 24, 26) as well as a lower bridge transistor (70, 84, 90) for controlling the current from the relevant terminal of the stator winding to the negative DC voltage line (78).

Abstract: An electronically commutated DC motor comprises a stator comprising at least one stator winding (22, 24, 26), a rotor (28) electromagnetically interacting with the stator, a positive and a negative DC voltage line (76, 78) for supplying power to the motor (20), in particular from a battery (77), a full bridge circuit (74) for controlling the current in the at least one stator winding (22, 24, 26), which full bridge circuit (74) comprises a plurality of bridge arms that each comprise an upper bridge transistor (66, 80, 86) for controlling the current from the positive DC voltage line (76) to an associated terminal (68; 82; 88) of that stator winding (22, 24, 26) as well as a lower bridge transistor (70, 84, 90) for controlling the current from the relevant terminal of the stator winding to the negative DC voltage line (78).

Abstract: The invention concerns a method for operating an electronically commutated motor (10) that is equipped with a current limiting arrangement which acts on a PWM controller (56). The latter, in operation, delivers PWM pulses (60) having a controllable pulse duty ratio (pwm) and a substantially constant frequency. In the event a predetermined upper limit value (Isoil; Iw) of the motor current (Iist) is exceeded, the current limiting arrangement effects a change in this pulse duty factor (pwm) in order to reduce the motor current (Iist). If the motor current (Iist) exceeds a predetermined upper limit value (Isoil; Iw) while the motor (10) is rotating, that limit value (Isoil; Iw) is raised by a timing member (260) during a predetermined time span (304) (FIG. 8: Iwmax), so that the available motor power is temporarily raised in the context of a load peak. If the rotor (24) is stalled, the limit value (Isoil) is not raised but instead is greatly lowered.