Who has made a diy a/f meter? Care to share what schematic you used? I'm looking for one that has been successfully followed since the ones I've tried (on the LM3914N chip) haven't worked. Not sure if I'm doing something wrong, or I just need a good diagram.

Thanks

 

i'm gonna be using the setup at www.diy-wb.com but that's a WB not an A?F gauge

 

The only ones that I have seen are the those. I have seen them work, but I can't say that I have made one on my own.

Here is the schematic that I found most referenced..

http://www.scirocco.org/tech/misc/afgauge/af.html

 

that's the one I'm building currently. My chips are on their way from singapore. When they get here I'll let you know how it turns out. I've ordered 5 chips, and I'll be making 3 gauges initially. does anybody know where I can get a 4.7k ohm potentiometer to adjust the resolution? radioshack discontinued them.

 

I just got the 10k ohm pots. Scale em down and they should do the trick Why would they even make a 4.7k pot - some special use?

Hmmm. I used the same reference. I wonder what I did wrong?? I gues it is time to get a new breadboard and start over.

 

I made/installed A/F meter based on http://www.scirocco.org/tech/misc/afgauge/af.html ... and it works great!

 

Thanks! That is the response I was looking for. Now I know the schematic is good, so I must have done something wrong. Time to try again.

Hmmm. I think I used a 12v regulator, for one thing. I guess that probably would have had something to do with it. Da'oh! Looks like I did everything else right, except for the 10kohm pots which shouldn't affect anything...

 

I made from the schematic at http://www.buckeyetriumphs.org/techn.../AFMonitor.htm
It's a really good implementation because it's nonlinear.
I made mine on a veroboard but I drew a PCB layout. If anyone's interested I'll post it here.

 

I made one on a tester board. It worked for about 2 weeks. I didn't use a voltage regulator, so I think I blew the LM3914N. Here is a pic



I'm going to rebuild another one using LEDS built into my rearview mirror that should be scalable once I get my TE WB built. But for now, I just want to make sure I'm in the right range and don't blow the engine due to detonation, which is all regular A/F guages are good for anyway.

 

wiring that up into your mirror is going to be a bitch, but the end result will be cool. I can't decide if I want to go with a bar of one color of leds or just single leds so I can make them whatever color I want.