Have gotten stuck on a problem at work. I have a small DC motor (specs: 6,000rpm, 1.5v, 220mA, 3-pole) located, inside of a product and have no visual access to. The only thing I have access to are the positive and negative terminals. Question is, how the heck can I measure the estimated RPM of the motor without cracking the item open? I've read a few ways here and there, but it's all over my head. I've tried reading the frequency with a multimeter, but that comes out to about 8kHz which can't be right.
Any help or pointers would be awesome!
Any help or pointers would be awesome!