Convert Ke Measured to "Actual" Ke ????

Electric Motors and Controllers
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mclovin   100 W

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Convert Ke Measured to "Actual" Ke ????

Post by mclovin » Sep 26 2011 11:05pm

I have a BLDC (650W from Golden Motors) that I just spun up with a power drill. I measure the shaft RPM and the phase voltages. Now that I have this data I'm struck with the thought "how does measured Ke relate to Ke used in motor simulations"?

My emperical data is:

Phase 1 - 26.4 V/Krpm
Pahse 2 - 26.0 V/Krpm
Pahse 3 - 26.4 V/Krpm

I'm a bit concrened as I expected a Ke in the high 40s because the no load speed at 48V is 1172 rpms. Hopefully it's just a math problem.

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liveforphysics   100 GW

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Re: Convert Ke Measured to "Actual" Ke ????

Post by liveforphysics » Sep 26 2011 11:14pm

How were you measuring voltage?
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liveforphysics   100 GW

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Re: Convert Ke Measured to "Actual" Ke ????

Post by liveforphysics » Sep 26 2011 11:18pm

TIberius (Nick) has a thread on measuring Kv (or Ke if you really must) that goes pretty deep on this very subject.
Each carcinogen vapor exposure includes a dice roll for cancer.

Each mutagen vapor exposure includes a dice roll for reproductive genetic defects in your children.

Each engine start sprays them into a shared atmosphere which includes beings not offered an opportunity to consent accepting these cancer experiences and defective genetics life experiences.

Every post is a free gift to the collective of minds composing the living bleeding edge of LEV development on our spaceship.

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mclovin   100 W

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Re: Convert Ke Measured to "Actual" Ke ????

Post by mclovin » Sep 26 2011 11:20pm

I measure each phase circuit individually with a volt meter measuring AC voltage.

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liveforphysics   100 GW

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Re: Convert Ke Measured to "Actual" Ke ????

Post by liveforphysics » Sep 26 2011 11:43pm

Read this thread. It will answer all your Kv related questions, and why normal measurements are tough.

http://endless-sphere.com/forums/viewto ... kv#p282324


Also, while reading that, appreciate what a badass awesome guy Tiberius is. :-) I wish he would post more often, I always enjoy his insights and projects.
Each carcinogen vapor exposure includes a dice roll for cancer.

Each mutagen vapor exposure includes a dice roll for reproductive genetic defects in your children.

Each engine start sprays them into a shared atmosphere which includes beings not offered an opportunity to consent accepting these cancer experiences and defective genetics life experiences.

Every post is a free gift to the collective of minds composing the living bleeding edge of LEV development on our spaceship.

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mclovin   100 W

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Posts: 184
Joined: Apr 04 2009 1:19pm
Location: Seattle

Re: Convert Ke Measured to "Actual" Ke ????

Post by mclovin » Sep 27 2011 2:42pm

Ya know, after I read the info i realized that i read all that before and somehow forgot...................it sucks getting old..... :roll:

Thanks for the link.

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