I'm looking to measure the angular velocity of an arm as it moves. It seems to be a difficult thing to research, since the term 'angular velocity/frequency' is usually reserved for other areas of circuit analysis.
I imagine something like a tachometer or a generator is most practical, but I can't find anything dealing with an incomplete rotation (i.e. about 90-120 degrees). Any help or push in the right direction would be greatly appreciated.
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