Thane Heins Perepiteia.

[hoptoad]

Well, we can, technically.  But somehow it never makes it to the post office.

I'll drink to that !  Cheers   

[i_ron]

I should probably add that the coil and magnet in my design (shown above) were also stationary.  Only the shield (which was ~1/4" thick would spin). 

Charlie,

That is a very clever design. Am I correct in assuming the area with the connecting side bars is a low
flux transmitter and flux is passed in the plain area?  What's the output like, decent?

Ron

[CRANKYpants]

Gee, I did my best to raise the class level of the group by mentioning BC wine... but I see it was a wasted effort....

WHY SO SNARKY I_RON 
YOU LOOKED HAPPY (AND SNAZZY) THE OTHER DAY WHEN YOU CAME OVER FOR A "VIDAL" BEER?

ANYWAY HERE IS WHAT I AM MAKING IN MY EFFORTS.
AS YOU CAN SEE THE NORTH POLE COIL INDUCED BACK EMF WILL HAPPILY ENTER THE
MAGNET SOUTH POLE AND NOT AFFECT THE ROTOR AT ALL. (FYI - CV YOUR COIL INDUCED FLUX SHOULD BE GOING IN THE OPPOSITE DIRECTION IN YOUR DIAGRAM - SEE LENZ "INDUCED FIELD").

THE MAGNETS ARE SHOWN TOUCHING BUT MAY END UP BEING SEPARATED SLIGHTLY.

CHEERS
Thane

[alan]

Great Thane, can you make a video with a scope connected to a coil (or both to show phase diff.) to show how it behaves when rpm changes?

[Charlie_V]

The way I drew it is correct.  As the shield moves over the north pole, the coil sees a DECREASING north pole.  This is the same as the lower left image of your Lenz drawing.  It is the same as pulling the north pole magnet away, the coil is going to set up the flux so that the core polarity facing the north pole  is south - just as I drew it.  Unfortunately, the shielding is also south, which causes a repulsion. 

The design I showed worked fine, but it was not back EMF free.