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Date: Thu, 24 Feb 2005 12:19:38 -0500
From: Ernest Christley <echristl@cisco.com>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Racemate alt/water pump
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Paul wrote:

> Here is a posting from someone who was not happy with their Racemate 
> alt/water pump assembly. Seems his problem is that he is running lower 
> rpm's than we are. Interesting reading, however. He seemed positive 
> regarding the idea of combining alt and water pump, and the quality of 
> the pump.  http://pages.zdnet.com/tonytryke/id8.html    Paul Conner


My understanding is that this problem was what prodded the developement 
of the alternator in the first place. The output voltage can be 
controlled by RPM.  It can also be controlled by magnet strength.  Since 
cars spend a significant amount of time at lower RPM, smart people 
developed a way to control the magnet strength through an electromagnet.

We don't have the problem that alternators were designed to fix.  We 
spend a very insignificant amount of time at idle.  Our systems will 
probably be using partial battery power starting on downwind as we begin 
the decent until we line up on the numbers and firewall it for the next 
takeoff.  I'll gladly trade that small drain for the simplicity of a 
generator, and I'll monitor my batteries carefully to account for it.