I'm a newbie to electrical projects, but I saw a neat project for building an Air Fuel Ratio Meter. I created the meter benched tested the meter with a 9V battery. Excited that I had completed my project I wired my meter to my cars 12V battery and not all the LEDs (10) light up. At most I get 4 of the 10 and it takes about 10 minutes for the 4 to light up.
The diagram can be seen at
http://www.scirocco.org/tech/misc/afgauge/diagram.jpg
Instead of the R1 = 2.3KΩ resistor and R2 = 3.3KΩ resistor that was called for in the diagram I used 2.2KΩ resistors.
Can anyone help my to try to figure out why my meter works with a 9V battery, but not with the 12V battery in my car?
The diagram can be seen at
http://www.scirocco.org/tech/misc/afgauge/diagram.jpg
Instead of the R1 = 2.3KΩ resistor and R2 = 3.3KΩ resistor that was called for in the diagram I used 2.2KΩ resistors.
Can anyone help my to try to figure out why my meter works with a 9V battery, but not with the 12V battery in my car?