Wind

[bj]

   So the new try, again a modified g.m. puts out what I expected.

Am happy, so far with output, but came up with a question, while

working on the test bench, on the next one.

   The question being--on any P.M. is the open circuit cogging

equal to losses in the P.M.  As in flux losses etc.  I suspect so,

as I can't see any other reason, but I have been dumb before.

   Only reason for the question, is, that if this is true, I can

concentrate on the magnetic portion of the P.M. while still on the

bench.  I am happy with the Neo's, windings, etc. am just trying

to improve efficiency with less losses.  The cogging is not large,

and I am sure there are no internal shorts, etc.  Have tried the same

P.M's with no diodes, and cogging is the same, or very close.

   Anyway, just trying to see if I am missing something obvious.

   bj

[RP]

No, cogging isn't really a loss.  The energy it takes to get the half way point is pretty much given back when the rotor "snaps" to the next postion.  It's just that it take a certain amount of energy to get it started.  

If you attach a heavy flywheel and get it turning at a moderate rate you'll find it really doesn't take much force to keep it turning.  In this case the flywheel stores the energy form the snap and gives back to push past the next cog.

[bj]

    RP

    With a nudge from you, that makes sense.  Guess I was looking for

a simple way, which there isn't.

    thanks

    bj