In this video, I tear down a Honda fuel pump DC motor and directly measure its speed using a tachometer to confirm that measurement of the motor speed via the ripple current generates the correct results. Animations are presented to provide a visualization of how the motor ripple current is generated.

0:00 Introduction
1:24 Animation of DC Motor
4:18 The Question!
5:28 Measuring the Motor Speed
8:05 Possible Explanation
9:14 Teardown of Motor
11:34 Bonus Footage