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  #1  
Old 01-22-2021, 03:08 PM
von_flyer von_flyer is offline
 
Join Date: Oct 2014
Location: Metamora, Michigan
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Default Garmin GSA28 with Ray Allen trim

I would like to verify the wiring of the GSA28 elevator A/P servo also using a Ray Allen T3-12A trim servo. Here is what I have. In addition to verifying the connections perhaps someone can tell me if the hat switch on the stick pulls an input to ground to select that direction of trim servo movement? Notice I did not draw the Cooley Hat Switch yet on terminals 11 and 12. Thank you in advance.
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  #2  
Old 01-22-2021, 03:28 PM
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mfleming mfleming is offline
 
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This is my simplified drawing for my Garmin system. My system has a GAD 27.

Without the GAD 27 all your pin outs look correct when I compare them to my master drawing. Without a GAD 27, you will need a relay to have a second trim switch.
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  #3  
Old 01-22-2021, 03:55 PM
von_flyer von_flyer is offline
 
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Thank you Michael. So the hat switch does take the signal to ground, true low. I donít plan on a second trim switch so no GAD27.

I assume the GP1 input is configured in the G3X and displays the trim position.
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  #4  
Old 01-22-2021, 04:01 PM
lr172 lr172 is offline
 
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Quote:
Originally Posted by von_flyer View Post
Thank you Michael. So the hat switch does take the signal to ground, true low. I don’t plan on a second trim switch so no GAD27.

I assume the GP1 input is configured in the G3X and displays the trim position.
No, not grounded.

Without the 27, you need 2 relays to send power, in both polarities to the the servo. The RA servo consumes an amp and you hat switch cannot handle that. The 28 goes into bypass mode when shut down and your switches / relays need to handle the full amp in this case. Also, the motor reverses by getting power in different polarities. The 28 is also looking for different polarities, when not in bypass mode.

The relay is typically activated via a low/ground on the hat switch, assuming you feed + on the other side of the relay coils.
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  #5  
Old 01-22-2021, 04:18 PM
Kyle Boatright Kyle Boatright is offline
 
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Location: Atlanta, GA
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Quote:
Originally Posted by lr172 View Post
No, not grounded.

Without the 27, you need 2 relays to send power, in both polarities to the the servo. The RA servo consumes an amp and you hat switch cannot handle that. The 28 goes into bypass mode when shut down and your switches / relays need to handle the full amp in this case. Also, the motor reverses by getting power in different polarities. The 28 is also looking for different polarities, when not in bypass mode.

The relay is typically activated via a low/ground on the hat switch, assuming you feed + on the other side of the relay coils.
.
Are you saying 2 relays per trim axis, so a total of 4 relays for pitch and roll trim?
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