Flap sensor voltage issue on Skyview

[Johnh38]

I’m having a problem/issue that I can’t seem to figure out in setting up my Flap sensor readings on Skyview widget screen.
I have assigned the pins on the EMS sensor settings page and am now trying to calibrate the widget under EMS Flap Calibration page.
I'm using the Ray Allen POS-12 position sensor wired as follows:
RA Wires                EMS Wires
White/Blue             Black (gnd) (Sharing connection w/Trim Servo)
White/Orange         White/Red (Sharing connection w/Trim Servo)
White/Green           Violet/Yellow (Pin #22)
Here is the issue.
The sensor voltage when the Flaps are level with ailerons  is 0.00 volts
As I continue to hold the flap switch down, the sensor voltage goes steadily up until it reaches 0.62 volts (approximately the mid-point of travel downward.) As I continue to keep the switch pressed down, the voltage begins to reverse direction, 0.62.0.59, 0.32...etc and approach 0.00 volts. The flaps are now at ~ 40 degrees (maximum downward deflection), but sensor voltage is back to 0.00 volts ???? Why the change back to zero? The EMS tells me that there hasn't been a change do I want to continue? Yes or No. I've tried saving it, but the widget is all screwed up when I do this.
I am not using a VP-X but am using an intelligent flap controller http://www.tcwtech.com/Installation instructions model IFC-10_rev1.1.pdf. What's stopping the voltage to continue to say 1.24 volts? (double the 0.62 volt value) This swing in voltage has me stumped.
Any help would be greatly appreciated.
Thanks,

john

 

[Johnh38]

No one has a solution or a workaround? I'd like to have the widget display correct Flap position information.

john

 

[bobl_51]

Have you verified that the RA position sensor lever actually continues to move in a single direction throughout the range of motion of your flaps? Depending on the mechanical linkage between the sensor and your flaps, the sensor lever may not be moving the way you think it should.

It sounds like the sensor position lever is not moving very far if the max voltage swing you get out of it is only 0.62 volts. Full range of motion of the sensor lever would swing 5.0 volts with your wiring connections.

 

[Dynon]

First, when you say "sharing connection with trim servo", I think you mean a trim position indicator, not an actual motor, correct? The SkyView 5V output is not designed to drive motors - it can only provide 300mA).

Back to the question at hand -

We'd expect a wiring error up to mess with your other positon sensors that shares wires, so, it does sound like a mechanical issue like the other poster above said, or possbly a bad sender.

While mis-wiring can definitely cause issues, we can't theorize the way yet given your data.

Some troubleshooting advice, using a multimeter:
Disconnect SkyView's wires, and just check the resistance on the position sensor as it moves. You can measure the resistance of the white/green position sensor wire against either of the other wires (power or ground). Between the two power wires the resistance is fixed (1K, 10K, 100K, whatver is inside it), so you can check that too. The resistance from sender wire to one end plus sender to other end should always be the same as end-end too.

One more thought: since you have a trim position sensor - if you have the (+) from the flap position hooked to the output of the trim, that could possibly explain the 0.62V, and it would change as you moved trim.

 

[Johnh38]

Thanks for the answers, I'll pull off the torque tube cover and look at the POS-12 connections and arm travel movement tomorrow morning.

You are correct in my mistake of sharing wires. I am using a Ray Allen T3-12A Trim Servo motor and am sharing connections with the same colored wires as the POS-12 (White/Blue & White/Orange as stated) The White/Green (sensor) is connected separately to Pin #22 a Violet/Yellow wire.

I will re-check all the wiring and troubleshoot using my multimeter n needed. Hopefully, it's just a simple wiring mistake. Thanks for the suggestions.

john

 

[jlakins]

I am not sure what you mean by sharing connection with trim servo. The position sensor does not share connections with the servo drive wires.
The White/Blue should go to ground
The white/orange should go to +5V (Supplied by EMS-220)
The White/Green  should still go to Violet/Yellow (Pin #22)

Jimmie

 

[sunfish]

sounds like you have both ends of the resistive Element connected. Hence voltage max in middle and tends to zero at each end.

 

[N82rb]

sounds like you have the pots connected together and have created a voltage divider from them. you are feeding 5v into each resistor, which is grounded at each end and the wiper is reading the voltage out. as each pot is changed the voltage at each pot is changing. each pot needs the voltage source on one wire, ground on the other and the line to the ems on the third. do not tie the two sensors together.

bob burns