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

["David Roden (Akron OH USA)" <roden ald net>]

Hmm, not much to go on in the description - we have to take his word that 
it's 
"working out really good in [his] electric vehicle."  Which he may have 
actually built: a 
web search on "installerjack" turns up a couple of classified ads from 
late in 2004 
looking for a glider.  FWIW, It also turns up this page:

http://www.solarandwind.com/contact.htm

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.