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Date: Thu, 09 Dec 2004 21:35:06 -0500
From: Ernest Christley <echristley@nc.rr.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] PM alternator (was: Re: gear drive for distributor
 and oil metering)
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Dale Rogers wrote:
> FWIW Dept.
> 
>    It might be worth reviewing this page:
> 
>    http://home.hiwaay.net/~langford/corvair/dynamo.html
> 
> since it was updated in August.  Of special interest is the 
> reference to 35A unit, at the bottom of the page.
> 
> Dale R.
> COZY MkIV #1254
>  

Just did a little more digesting of what Mr. Langford has to say.  The 
sentence of interest is:

"At 800 rpm it's putting out 13.2 volts and and puts out 14.5 volts at 
1100 rpm and higher. "

It appears that he's talking engine RPM.  He indicates he's using a 6" 
pulley, and the one pictured on the dynamo appears to be about 2.5". 
That would be somewhere around a 6:1 reduction.  Driving it off the 
metering pumps pulley at half engine RPM, we're looking at turning it 
only 3000 or so RPM in cruise.  He's spinning it at 6000 or so to get 
battery charging voltage.


-- 
http://www.ernest.isa-geek.org/
"This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."