Stepper motors
- Rotates only by fixed amounts, and controlled by a sequence of digital outputs
- Stepper motors typically (for bipolar steppers) have 4 wires, two each for adjacent coils
- Other, more complicated drive patterns such as full-step drive (two phases on), half-stepping etc. possible
- Step angles of 1.8o, 3.6o, 7.2o etc. are typical
Courtesy : https://howtomechatronics.com/how-it-works/electrical-engineering/stepper-motor/
Another good website with animations: http://www.pcbheaven.com/wikipages/How_Stepper_Motors_Work/
- Open loop control – no feedback-based correction built into the motor unlike servos
- Good for positional control where turn angle is not limited and where the torque required is relatively constant
- Used in printers, 3D printers, rack and pinion based actuators
To do : Lookup and go through Arduino Stepper Library
Other Motors
- Brushless DC (BLDC) motors
- Similar to DC motors, but an electronic circuit replaces brush + commutator. Used in electric scooters etc.
- Induction / synchronous motors
- Used in fans etc, works on AC; the mechanism of operation is somewhat different from that of DC motors