Brushless DC electric motor
![The motor from a 3.5](/Images/godic/202501/11/Floppy_drive_spindle_motor_open1904.jpg")
![Schematic for delta and wye winding styles. (This image does not illustrate the motor's inductive and generator-like properties)](/Images/godic/202501/11/Wye-delta.svg1904.png")
![The four poles on the stator of a two-phase brushless motor. This is part of a computer cooling fan; the rotor has been removed.](/Images/godic/202501/11/Poles1905.jpg")
![A microprocessor-controlled BLDC motor powering a micro radio-controlled airplane. This external rotor motor weighs 5 g and consumes approximately 11 W.](/Images/godic/202501/11/Brushless-Motor-DUM601905.jpg")
Brushless DC electric motor (BLDC motors, BL motors) also known as electronically commutated motors (ECMs, EC motors) are synchronous motors that are powered by a DC electric source via an integrated inverter/switching power supply, which produces an AC electric signal to drive the motor. In this context, AC, alternating current, does not imply a sinusoidal waveform, but rather a bi-directional current with no restriction on waveform. Additional sensors and electronics control the inverter output amplitude and waveform (and therefore percent of DC bus usage/efficiency) and frequency (i.e. rotor speed).