View Full Version : A question about transducer function
waistgunner
January 3rd 09, 04:15 AM
In respect to an autopilot system, can anyone describe the path, more so what happens, from the A/P control in the cockpit to the transducer and lastly the flight controls?
I know what a transducer does.  it converts one form of energy into a different form  The transducer in this system is a pressure transducer.  what type of energy enters the transducer and what does it convert it to in respect to the A/P system?
thanks,
  matt
James M. Knox
January 12th 09, 10:10 PM
waistgunner > wrote in 
:
> 
> In respect to an autopilot system, can anyone describe the path, more so
> what happens, from the A/P control in the cockpit to the transducer and
> lastly the flight controls?
> I know what a transducer does.  it converts one form of energy into a
> different form  The transducer in this system is a pressure transducer.
> what type of energy enters the transducer and what does it convert it
> to in respect to the A/P system?
[Warning:  Extremely simplified answer.]
The pressure transducer is for altitude.  The air pressure is converted by 
the tranducer to a voltage.  This is compared with another semi-fixed 
voltage representing the desired altitude.  That difference is amplified 
and fed by the autopilot to a servo motor to move the control surfaces to 
cause a climb (or descent, depending on the sign of the difference).
Similar for direction hold.  In the simplest case (wing leveler) a pickoff 
from the AH generates a voltage that corresponds to the amount by which the 
wings are no longer level (and the sign represents left or right wing dip).  
The signal is amplified and fed to aileron servos to move them in a 
direction opposite to that of the bank angle.  Bingo... the wings level 
themselves again.  
Add a similar input from a heading bug off the DG and you have heading 
hold.  Add a voltage from the VOR or GPS deviation and you have tracking.  
Variations include roll-rate gyros and accelerometer transducers.
 
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James M. Knox
TriSoft                        ph  512-385-0316
1300 Koenig Lane West          fax 512-371-5716
Suite 200
Austin, Tx 78756              
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KateDaring52
July 4th 11, 04:23 AM
Does your GG mod make your rex RUN like a grocery getter too?
Great post! It's very nice. Thank you so much for your post.
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