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Unread 30-10-2004, 01:36
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Kevin Watson Kevin Watson is offline
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Re: Testing Motor for Specs?

Quote:
Originally Posted by indieFan
There were three motors that were run off of the same battery pack. Two of them appear identical. Since the third was different, wouldn't the normal operating voltage be dependent on the voltage division created by the electronics of the truck? If this is the case, can just looking at the resistors and tracing where the leads go on the board serve as the information for calculating the necessary voltage division?

Thanks,
indieFan
To elaborate on what Dave said above, you can't really do these calculations based upon the DC resistance of the windings alone because they only behave in a purely resistive fashion at stall (i.e., when the motor shaft isn't rotating). Because the windings have an inductive component, they are able to store energy in the surrounding magnetic field when they're energized, giving it back in the form of Back EMF (Electromotive Force) when the field collapses. If you're interested in learning more (which I would encourage), have a look at this website or just google on something like "DC Motor Model"

BTW, whilst testing motors it's best not to do it late at night while whacked-out on frosted cherry pop tarts and diet coke.

-Kevin
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Kevin Watson
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