Tank - low level sensors - cheap

[AndyDrain]

I have been working with these sensors for some time but always through a small Arduino driven multi function display.

 

I realised that a very cheap 12 v system could be used.

 

 

The sensors are placed around the 5 litre level and are set to display a green LED all the time fuel is present.  That way if the system fails the LED goes off.  If the Black wire, on the sensor, is connected to Positive the light will be ON if there is low fuel.  (A Red LED could then be used).

 

If the Sensor cover is removed a small trimming screw is available that needs to be adjusted to allow for tank wall thickness. I have a 3d printer file available for a plastic holder that can be stuck to the tank and the sensor slid in.

 

The sensor is available from many places.  As example here. 

 

The LED was from Jaycar.  They also have larger ones if this is too small.

 

Total cost under NZ$20 per tank.

 

As it is 12 v the frame can be used for Earth so only minimal wiring is required. As well as the wing tanks one could be added to the header as  back up to the current system.

 

[eightyknots]

This is an interesting idea.

 

Because the inboard tanks on the Savannah show fuel levels visually, via the clear Rilsan tubes, do you just use this for the outboard tanks?

[AndyDrain]

I actually have them on all four - just because I can.  I find the Rislan levels hard to see when they get low so an extra clue is good. I plan to add one to the header tank "one day".

They naturally flash as the fuel sloshes around.