EC Motors Versus Brushed DC Motors
:
Brushed DC
Rotor | Windings and commutator | |
---|---|---|
Stator | Permanent magnets and brushes | |
Motor voltage | DC voltage at 2 wires |
EC
Rotor | Permanent magnets | |
---|---|---|
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 |