On Aug 15, 2009, at 9:47 PM, Kyle Mcallister wrote:
--- On Fri, 8/14/09, Horace Heffner <[email protected]> wrote:
Well, Kyle, the ball bearing motor may just have some
anomalies left up its sleeves. Looks like the back emf
possibly doesn't increase with rpms, at least in some range.
How strange is that?
Do you want me to rig that transformer I made up to it, see if it
will turn the thing? If it does, then battery overload problems are
out of the picture.
If your rig is still set up it would be good to measure the voltage
drop across the motor when stopped but current is running. Then do
the same with it spinning, in order to determine the back-emf by
subtracting out the stopped voltage drop. I would try to watch the
voltage across the motor as it spins up, to see if it varies much. A
DC test of this may be more stable and meaningful than an AC test,
but if you get the AC version running and can do longer runs then it
may be also useful to look at what happens to the back-emf without
load vs with a load on it of some kind, maybe just some kind of
manual breaking.
Still have to also do John Berry's Hiddink experiment.
Gotta find some motivation somewhere.
--Kyle
Sometimes you just need a rest. I'm a bit burned out myself.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
