0-1V LED schematic

[darbee63]

Just wondering if somebody could help me out.

I'm looking for a schematic for building an air/fuel ratio meter that reads 0-1v dc in tenth of a volt or millivolt increments.
Basically it'll be for reading the signal for my air/fuel ratio that goes to the ECM and then to read the signal I send as well.
I could buy 1, but I'd need 2. Being that my vehicle has 2 O2 sensors on the exhaust, then instead of riding with my meter on my seat. I'd like to see the signal which would mean I'd need 2 more.
Or I'll have to buy 2 dual air/fuel ratio meters, and I'm thinking I can build one a heck of a lot cheaper if I can find a schematic.

Any help would be greatly appreciated.

Thanks Darbee63

[BOA279]

I think I can help.  I just recently started trying to crank these out myself....I even etched out some pcb's but discovered I forgot (read: was asleep while drawing out pcb) the variable resistors to tune it with.  anyway, here is exactly what your looking for...

[Creativity]

interesting does it need any calibration?

[CarbedNotch]

Someone on YouTube has got one of these. I'm sure you could contact him and he provides all the information. He's even got a website on o2 sensors.
Lemme know if you cant find him. I'll link it.

[darbee63]

Thanks BOA279.

I kicked around on some mechanic websites and found a  schematic exactly like the one you posted. I'm currenly going to use another configuration thats real similar but without the voltage regulator.
But if your looking at pumping them out, this particular schematic is a 1 wire change to make it a 0-5v indicator as well.

Which will work good for newer cars that use a 0-5v O2 sensor with 0 being rich and 5v being lean.
The older models will use a 0-1v with 0 being lean and 1 being rich.
From a business standpoint I think this design is more practical because you can sell either or with very little change and use the same board.
Just make sure to tell whoever orders them that they need to research the year and make to see if they have a 2,3,4, or 5 wire setup, 1 or 2 sensors or if its 0-1v or 0-5v.
So many people are selling generators and not explaining the ramifications if they dont trick the O2 sensor.
I fear the lack of info on O2 sensors might be the next step of misinformation for some of these do-it-yourselfers, who'll then just toss out everything in disgust and claim it doesn't work.

My vehicle has 2 O2 sensors 1 on each bank, so I'll need to build 4.
Only because I want to see the before and after signal on each bank.
Plus I'll be introducing a signal on the outgoing side, so I dont have to worry about the draw down factor.

I ended up finding a boatload of differant configurations. Right now I'm going witht the easiest, but wont start building until I get some more 20 pin sockets.

Single A/F meters run anywhere from 35-100.00. and theres not many dual ones on the market. But I do think its critical to look at the before and after signal, so you know if your in an open loop or closed loop.

Again thanks
darbee63