EMS-D120 and 12V low fuel light

[matt.hocker]

Hi everyone. My airplane has no fuel level sensors in the wing tanks but it does have a sensor in the central feeder tank (that both wing tanks feed into) which indicates a low fuel situation. This occurs at less than 6 liters of fuel in the mixing tank and illuminates a 12V "low fuel" light on the panel.

I'd like to interface this into the EMS-D120 so that I could get an audible and visual alarm, in addition to the light on the panel. I looked at the General Purpose inputs, but they are resistive as are the two (unused) fuel level sensors.

Does anyone have any ideas how I could trigger a low fuel warning on the EMS when this 12V line is enabled?

Thanks.

 

[Dynon]

You want to use one of the contact inputs for this. You'll need to be able to show it open (or powered) and ground, though. I'll ask one of my engineering colleagues weigh in on this tomorrow.

 

[dynonsupport]

The contact inputs are not resistive. They have a pull-up, but they sense voltage. The contact inputs can handle "12V" from the aircraft just fine.

All you need to do is hook the contact input to the switched side of you low fuel light. This will be 12V sometimes, and 0V other times. Which one is "low fuel" depends on the configuration, but you can adjust this in the D120.

Now in the D120, just set up that contact to display. It should show one state when you have low fuel, and the other state when you are not low. Just set up the names for the right states.