Monday, July 13th, 2009 | No Comments

I’m sure you have seen many air/fuel ratio meters for sale. In many cases this is small gauge with many colored leds. If you have little experience in welding small parts you can make this useful gauge yourself.

D.I.Y. a/f ratio meter budget is incredible small. You will spend only about 7 Euro on main parts. You must buy 10 diode leds (6 red, 2 yellow and 2 green), 1 diode (code: 1N4007), 2 resistors (any kind 2 kohm), chip (code: LM 3914N), some wires and universal plate. If you have any experience in welding electronic parts this easy job won’t take long. You should print electronic scheme (first picture on right top) and weld all parts. I suggest to weld chip first of all and after weld 10 led diodes, wires, resistors and diode. (more…)