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Smooth Commutation Drive

Next to aerodynamic noise and bearing related noises, the so called "commutation noise" or "switching noise" can play a major role in the noise emission of axial fans with brushless DC motors. At each transition from one stator coil to another, the rotor receives a sudden torque pulse when the next coil switches on. Each of these torque pulses causes a minute deformation of the whole fan structure. Depending on rpm, torque and the material of the fan, this can result in noticeable noises.

Noctua's Smooth Commutation Drive system provides more continuous switching in order to achieve a smoother transition between the stator coils and thereby significantly contributes to the fan's overall quietness. The second generation of this technology (SCD2) further improves running smoothness and reduces minute noises in close proximity to the motor.

25.10.2014 - NH-D15
Test verdict: "To wszystko razem daje nam ocenę 5/5 oraz aż 3 rekomendacje, za wydajność, kulturę pracy i jakość." (Marcin Żyto,

25.10.2014 - Conseil Config NH-L9i
Test verdict: "[L]es Noctua NH-l9x seront d'excellents choix de ventirads lors du montage d'une configuration mini-ITX de très petite taille." (Christian Marchini, Conseil Config)

25.10.2014 - NF-A4x10 5V
Test verdict: "Auf Grund der sehr guten Verarbeitung, der edlen Optik und dem sehr großen Lieferumfang, hat sich der Noctua NF-A4x10 wirklich einen Gold-Award verdient." (André Sterba,

25.10.2014 - NF-A8 PWM
Test verdict: "Oczywiście tego wentylatory, które przy zachowaniu dobrej kultury pracy cechuje także wysoka jakość wykonania zasługują także na nagrodę 100% QUALITY!" (Łukasz Talkowski,