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From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: [FlyRotary] Cooling fans
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
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Date: Sun, 10 Aug 2003 19:42:02 -0400
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"Tommy James" <twjames@healed.org>:
>>>What do those with "Fan" experience say about preventing this kind of
problem?<<<

It's not fan experience, per se, but we use an interesting little circuit on 
the flap motors of our Lancairs to keep them from coasting when we shut off 
the current to move the flaps.  Put the power to the motor through a DPDT 
relay... the NO contacts are the +/- power in, the common contacts go to the 
motor.  You connect the NC contacts together so you short out the current 
coming from the motor-now-generator when the relay is de-energized.  The short 
across the motor works like a brake and keeps it (or stops it, in our case) 
from spinning.  I don't see why this same thinking couldn't be applied to a 
fan motor.  Just a thought.

           <Marv>