Speed regulation of a (brushed) DC motor without using a tachogenerator

In this little project I want to show you methods how to keep the rotation speed of a (brushed) DC motor constant (independant of the torque) without using a tacho generator.

Maybe these principles (EMF regulation and RI - compensation) are long forgotten because of the use of modern brushless DC motors or stepper motors. But the use of brushed DC motors is still reasonable because of the higher amount of control installation for the other motors.
Interested? - then please watch my video for more information:

https://www.youtube.com/watch?v=6IEVBQyKIF4