Figure 5 - Typical speed curve for permanent magnet motors, with linear torque-speed proportionality. DC motor commutation can be either brushed or brushless, both of which offer specific advantages.
How to Make a Magnet Motor Generator 220v Using DC Motor ...
Small permanent magnet motors can be used as tachometer generators in some applications. A direct current (DC) permanent magnet tachogenerator design is shown below. In this particular device, the ...