Fwd: eddy current brake

[Roy]

tom cloud wrote:
> 
> >Hi there,
> >
> >think the Eddy.effect is exlained enough, so lets go back where the idea came
> >from (can't remember who it was, but what it was):
> >reducing/removing backlash of the ignition rotor!
> 
> Help me understand ..... (I've listened to related discussions re
> ignition control for a while)
> 
> I hear the 4 pointed star crank pickup isn't good enough to use
> a PLL to develop nth degree resolution.
> 
> Same for the distributor pickup.
> 
> So, seems everyone wants to use either the flywheel teeth or a gear
> attached to the cam (maybe even the cam gear??).  Is that right?
> 
> I know n-nothing -- at least not practically.  Seems to me the crank
> pickup with PLL would work.  Any variation due to speed of the tooth
> approaching the pickup giving faster rise time ergo changing reference
> could be compensated for either in an analog circuit or in a confuser
> using either a lookup table or (probably) a simple trig function.
> I don't think the crank's gonna have much backlash :-)
> 
> As far as backlash, why wouldn't an averaging function take care of
> that?  After all, how fast can an engine change speed? and the delta-speed
> seems to me to be the most egregious factor (pun) in successfully
> implementing some kind of smoothing circuit (maybe even an f-v convertor ??)
> 
> Now, there's an idea I absolutely haven't explored .... Do an f-v conversion
> and filter it ??? would that work?
> 
> Tom Cloud <cloud at peaches.ph.utexas.edu>
> 
>
> Use optical pickup sensors with digital outputs and your signal will > have constant amplitude amd mark-space ratio just the period will > change with engine angular velocity.  I have used this method on > several motorcycles.