[Mike]

Originally Posted by GreatOldOne

My friend Rob came round tonight, and we prototyped the low fuel circuit. I now have all the correct values for the components to get a 60 second delay before the lamp lights.



http://www.youtube.com/watch?v=eK9cVIQ4zqE

The video shows it in action - the delay has been reduced to about 4 secs for testing purposes. It turns on at about 1/8th of tank, set by a pot that determines the threshold. Another pot simulates the sender - turning it past the threshold, the lamp lights once after the preset delay, and immediately switches off if the the sender input goes above threshold again.

I'll be posting up the completed circuit, and Rob will write a more thorough explanation of how it all works. It looks as if it'll be simple to modify the circuit for any sender / meter combination as well, simply by changing the values of some resistors on the input stage of the circuit.

Next step - build it for real.

Are all those wires needed?!