These motors use brushes that rub on a segmented copper ring so that the current through the armature coils alternates as the motor spins. We opened one up in the photo below, so you can see the magnets and coils in the left and the spring-loaded brushes on the right.
Applications:
-
Toys
-
Cell Phone Buzzers
-
Cordless Tools
- RC Servos
- Gear Motors
Advantages:
-
Inexpensive
-
Lightweight
-
Reasonably Efficient
-
Good low-speed torque
Limitations:
- Noise - In addition to the audible whine from the commutator brushes, these motors create a lot of electrical noise which can find its way back into other circuitry and cause problems.