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Trim position signal to EFIS

pilote999

Member
I want to remove my analog trim indicator to my new GRT Sport Ex on 1 of my analog input. I have 5 wires coming from the trim: White/black, white/blue, white/red, white/green and white/orange.

On which wires I have to connect? Is it a resistive input? Do I need a pull-up resistor connected to the 4.8vdc reference or the 12v???

Thanks for your help!
 
Trim position wiring

Here's what I found in the GRT documentation:

Trim-Position-Wiring.png


http://grtavionics.com/media/Sport-SX-EX-Install-Rev-G-April-2017.pdf
 
Thanks Michey,

According to the schematic, the Green wire should be the same as the Green/White, the Orange as the White/Orange and White/Blue the GND.

I will contact GRT to confirm.

Thanks again!
 
I only know the HXr, which has internal pull ups. Not sure if the Sport uses those, so you'll need to ask them if a 5V source will be required. With the internal pull ups, it can be done with grounds.

Definitely do not use the diagram posted above, as that is for the EIS and not the EFIS.

Larry
 
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I think I have a Ray Allen trim servo. I went their website and can not find the exact color c of the 5 wires. Does anybody know the purposes of the 5 wires (white/Green, white/orange, white/blue, white/black, white/red)???

Thanks again for your help!

Raynald
 
i dont have the drawings handy, but the five wires are power, ground, and three to the pot. I believe the white/red is power, white black is ground and the other three are the pot.

to figure it out without a schematic, there should be a constant resistance, 5k or 10k if i remember correctly, across two of the wires as the servo is moved. there should be a changing resistance between the other one and either of the two constants.

--------\/\/\/\/\/------
:
:----------

one of the constanstants goes to the 5v output of the eifs and the other contstant goes to ground. the third goes to the input for the efis. you will get a voltage of 0 to 5 volts on the other line depending on the position of the wiper.

bob burns
RV-4 N82RB
 
I think I have a Ray Allen trim servo. I went their website and can not find the exact color c of the 5 wires. Does anybody know the purposes of the 5 wires (white/Green, white/orange, white/blue, white/black, white/red)???

Thanks again for your help!

Raynald

The two white wires are power to actuate the motor. The other three (green orange blue) are for the potentiometer (standard design w/ a wire for each end of the resistor and one for the wiper. You can use an ohm meter to figure out which wire is which. When your connected to the two ends, you will get full resistance (5K or 10K, I forget which). When you are on the wiper and one end, you will get something less. Wiper and one side + wiper and opposite side = the full end to end resistance.

If your model has pull ups, you can connect one end to ground and then bridge the other two wires (end + wiper) and connect to analog input. In configuration settiings you turn the pull up on for that analog input. Here is a link with wire colors for this approach http://grtavionics.com/media/Flap-Trim-Sensor-A5.pdf

Larry
 
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If your model has pull ups, you can connect one end to ground and then bridge the other two wires (end + wiper) and connect to analog input.

Larry

If your model has pull up resistors, you can connect one end to ground, and the wiper connection to an analog input. Also connecting the other end to the input won?t hurt anything, but it doesn?t do anything, either.
 
In the other thread on this project, it is stated that you have a EIS4000. That being the case, the diagram above is correct.

The white/red and white/black are the power to the servo. The others are the position information. Connect them as shown. They will connect to your EIS4000.

I did this a few years ago and the following is the note I got from GRT.

Hello Jim,
The Sport HS and SX do not have analog inputs. You can setup the Flap position by using a spare EIS aux input. In the EIS, configure the scale factor to 250 and the offset to 0. In the EFIS Set Menu, Engine page, set the corresponding EIS aux input to flaps. Then perform the flap calibration in the Set Menu, General Setup page.

The circuit requires a pullup to the 4.8v supply on the EIS. Circuit is here except that the instead of analog input to EFIS, use EIS Aux input.
-Marc Robertson
Engineer
GRT Avionics Inc.
3133 Madison Ave SE
Wyoming, MI 49548
PH 616 245-7700
FX 616 245-7707

On 8/4/2016 5:52 PM, Jim wrote:
Good Day,

I?m adding a Ray Allen flap position indicator to my aircraft. I have Sport HS EFIS and EIS. I understand the signal from the Ray Allen must be one of my aux inputs on the EIS. I can?t seem to find what should be the SF and OFF settings for this input?

Thank you.



Jim Butcher
 
If your model has pull up resistors, you can connect one end to ground, and the wiper connection to an analog input. Also connecting the other end to the input won?t hurt anything, but it doesn?t do anything, either.

That was my thinking and if I recall, how mine was wired when I switched from dynon. But it is the way that GRT recommends it so didn't feel right suggesting anything but that.

Larry
 
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