|I designed this 30-LED meter to use with my wideband
I wanted to have a slim meter to mount under the dash
with only the row of LED's visible.
The voltage range is 1.5 Volts for rich ( Lambda 0.70 ,
AFR 10 ) to 3.0 Volts for lean ( Lambda 1.44 , AFR 21 ).
For reference I added two additional LED's that are lit
all the time.
One green for Lambda 0.86 (Maximum power).
One yellow for lambda 1.05 ( Best fuel economy ).
I used green LED's between max power and max fuel
I used yellow LED's above the max power LED and up to lambda
0.75 (AFR 11). That is the range used for supercharged
I used red LED's for values leaner than the Best fuel
economy LED and for values richer than lambda 0.75 (AFR 11).