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Old 08-14-2019, 05:42 PM
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itsid itsid is offline
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rev per volt under load is dependend on the load itself.
120 lbs rider at 7:1 and 300 lbs rider @ 5:1 makes a whole lot of a different load
So no in the end it's just some arbitrary number..
If you however intend to do that for all of your PMDCs
(BLDC are a different bred and cannot be measured that way)
it'd allow us to compare two "different" motors under reasonably identical loads

So yeah keep on.

BUT: as I said the only real use of such is to have the voltage read at the very instant the load is applied..
slightly before or after is basically adding another variant (the batpack, charge density, self recovery rate, capacity etc..)
That's why lab testing is usually done with fixed voltage and current power sources and
of course fixed loads.

Nevermind...

I have a variable voltage divider in mind, I just have to see if it's cheaper to have it self-adjusting (i.e. by a chip) or manually adjusting (i.e. by a poti)
it'll need to get clipped for a decent resolution of course, but I think I can do that quite cheaply.
the rest is a simple arduino (chinese clone for a dollar will do) and the inductive pickup you have up there..
Oh no.. an SD card module for data storage
I'll make the parts list as I go, but I think it'll have a low partscount and low costs in the end...
we'll see.

'sid
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