Hi everyone,

I have somewhat resolved my torque measurement issue involving my small digital scale (sample rate issues).

I am posting here my first (mostly) complete data:
The torque data comes from a small digital scale (-+ 0.2g)
The current comes form a shunt = 5.1 ohms. No correction was made for the power dissipated by the shunt, so there's some more to add to the output efficiency.

Load: 2 grams @ 2.33 inch torque arm
Voltage: Pulse 16VDC
Current: approx 75% of 0.196A Peak = 0.147Aavg
  (see picture - classic R-L inductor charge curve)
Pulse Duty Cycle: approx 13%
Motor Speed: 1001RPM

Results:
Input Power: 0.30576 Watts
Output Horsepower: 0.000163022 H.P.
Output Equivalent: 0.124615 Watts

Efficiency: about 40% (without shunt power figured in)

I think this is all right but any input is appreciated.

Thanks,

Greg

Ch2 is the 5.1 ohm current shunt

I have found the Keppe Motor manual on
...
Link deleted due to copyright infringement (admin)

for gmeast:
You have tried to measure the energy lost to friction?

Quote from: alessiof76 on April 22, 2009, 03:54:24 PM
for gmeast:
You have tried to measure the energy lost to friction?

Hi alessiof76,

I ran it by hand  in both directions and watched the gram scale.  It only loads .5 grams in either direction.  The bearings are very good, but 0.5 grams is still 25% percent waste tho.

I have not put a diode to recover any power from the field at the reed switch nor tried to run a neon lamp yet ... that's next.  This kind of dyno washes out the drag from the inner bearings but unfortunately not the outer bearings ... gives you net power minus outer bearing(s) drag.

Thanks for commenting,

Greg

Hi all,

I contacted the Keppe Motor people from their website to ask if the Version 3 manual was available yet.  I got a prompt reply that it was and they provided the link.  As some of you know there is a contract they want you to agree to and in that contract (clause 6) it states the Ver 3 manual costs $50.00 and the Ver 3 Kit costs $350.00.

As I stepped through the process the PayPal site came up with an 'Amount Due' of $250.00 ! @%$#&...so I sent them off an email asking them to fix that so no one gets taken on a technicality.

So be careful with you 'clicks'.  Just a friendly heads-up for now.  I think I'll wait for the Ver 3 to leak onto the internet like the Ver 1 did.

Greg