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Date: Thu, 02 Jun 2011 08:28:33 -0400
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From: Paul Miller <paul@tbm700.com>
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Subject: Re: [LML] Re: Change the speed of the ROC servo  for trim
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We're on the same page Colyn but I've got a weird setup.  A 24v buss and 
12v servos.  The trim box is something made by PreciseFlight with no 
wiring diagram and no response from the firm.  Lancair Avionics put it 
in.  I presume I could feed that box with 12v and see what happens.  
Then the TruTrak feeds the autotrim module which was just upgraded for 
free by TruTrak (thanks) to handle the unplanned 24v that seems to go to 
the pitch trim in many aircraft (source:TruTrak).  The pitch trim output 
from the Precise Box goes to a 200k pot and is also in series with the 
autotrim also has a variable speed adjustment, probably another pot.

As I said in a past post, I'll put an airspeed switch coupled with a PWM 
output to feed the RAC pitch trim servo and get rid of all the pots.

On 5/31/2011 9:33 AM, Colyn Case wrote:
> Paul,
> I would say the added value is more exposure.
> I'm not sure they designed the speed control to have a 28V input.   I 
> think they would expect you to put their 28v ->12v converter in.   The 
> latter may also be just a resistor but the point is they worked out 
> all the power dissipation requirements etc.
>