Re: (ET) Any takers? Sounds like a scam but who knows?

[Robert Adsett <subscriptions aeolusdevelopment com>]

At 02:02 PM 2/3/05 -0500, David Roden (Akron OH USA) wrote:
> Wild guess: he's built a mechanical PWM device, using a modified 
> commutator from a
> starter motor, driven by another motor.  Envision a commutator where the 
> segments
> are cut into triangles, so at one end of the com the segments are close 
> together, and
> at the other they're far apart.  With something like this, the commutator 
> is just a big
> switch.  You spin it and vary the duty cycle by moving the brushes fore 
> and aft.
>
> The idea is an old one; I believe it was tried on a few EVs early in the 
> 20th century. It
> was also advocated for hobbyist EVs about 30 years ago in a couple of 
> magazine
> articles.  So (if I'm right) it's no wonder he can't patent it.  Note that 
> I'm just guessing
> at this; it could be anything.

Rather clever, I suspect you would still need a flyback diode  and brush 
wear might be an issue.

Reminds me a bit (in a round-about way) of a control mechanism apparently 
used in some French material handling vehicles.  They would run a tap off 
of each cell and switch in a varying number of cells depending on throttle 
position.  There was a mechanical mechanism to cycle which cells were 
tapped on each acceleration so that the battery would discharge evenly.

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                        Kelvin Throop, III