EC Motors Versus Brushed DC Motors


Brushed DC

Rotor Windings and commutator ec motor
Stator Permanent magnets and brushes
Motor voltage DC voltage at 2 wires



Rotor Permanent magnets ec motor
Stator Windings ; Hall sensors
Motor voltage PWM DC voltage from driver circuitry ; 3 phases


Applicational Notes

No brushes No wear of brushes
No sparkling
No surface contact issue
High lifetime (only bearing life)
Low noise
Low Electromagn. Interference EMI
High reliability
Less sensitive to ambient pollution
High speed possible
Magnets in rotor Lower rotor inertia than DC motor Fast acceleration – highly dynamic
Windings in stator Windings in contact to housing – good heat transfer High power/size ratio
No commutator Shorter rotor 20…30% High power/size ratio
Driver circuitry
Hall sensors
Additional costs Total costs higher than brushed DC motor Exception:
For speed control, brushed DC needs driver circuitry + possibly sensors too