I figured it out using a scope and a current clamp as a transducer. The pulses from the voltage output are pretty well defined and its accurate enough for what I needed.
Found this write-up which I think describes what I'm looking for:
http://www.precisionmicrodrives.com/tech-blog/2011/06/08/using-dc-motor-commutation-spikes-to-measure-motor-speed-rpm
What would I need and how would I actually take the measurements?
I am doing some research on electric fuel pumps and I would like to determine the RPM. The motor is enclosed so none of the rotating parts are readily accessible. I have a test bench with a variable voltage DC power supply, back pressure control, and appropriate test fluid so the pumps are...
I think I'm just going to take out the fuse. I've honestly never blown it and according to my boss that did the design on the original equipment the fuse was originally to protect the power supply and not the pump. Thanks for the help.
The max current on the main circuit is 30A. 5A is the AUX output limit which I am not using. When testing fuel pumps I will see 10A-12A at most. I would like to avoid anything above that just in case something goes wrong. I would rather not have sparks or excess heat around a flammable test...
I have a fuel pump tester with a power supply that has a sense circuit for automatic voltage compensation. The power output is controlled by a remote switch to the power supply so there is no switch in the main circuit itself. My problem is that the sense circuit cannot be connected to the pump...
