DIY AFR gauge

[levin818]

Hi,
I wish to construst a 20 LEDs AFR gauge. Currently is trying to making up the circuit design.

From branded AFR available in the market, the LED arrangement are as follow:
Rich - 6 LEDs
Stoich - 10 LEDs
Lean - 4 LEDs

Can somebody tell me what is the voltage range for Rich, Stoich and Lean?
Any useful webside to recomend?

Thanks!

 

[szekeiemme]

pm akajonz .. u can find his nick at proton/perodua = kelisa gathering.. he done his ..nice n working

 

[3R1C]

just to help you out

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

 

[Indecided]

Eric,

sial kamu :P go n sleep la... no need to wake up for test meh?

Zzz

 

[3R1C]

It's okie bro.
My project will start in 2 weeks time.
After that gonna be city lights and follow with vtec warning lights :P

 

[3R1C]

**UPDATE**
I've done mine and now I'm just waiting for that chip to come in. Should be sometime this week or next. can't wait to hook it up. thanks to INDECIDED for helping me looking for the chips :)

I'll post some pics probably tomorrow night or when I've got the chip in and show if it works. Happy DIY to the rest.

Hasta la vista!

 

[sky_kids]

grreat
shows up the pic..
how much u did all those??

wanna do mine
jus duno where to fix it
duno which wire

 

[3R1C]

Pics will be uploaded later.
Total cost in making it roughly will be USD$ 5 - 7
There're only 3 wires that you need to tap to your car.
1 - 12v
2 - Ground
3 - O2 signal (from ur ecu or directly from ur O2 sensor)

 

[levin818]

Tks 3R1C for the informative site :)

Constructing the project is easy, but selecting a correct value for R1 and R2 is difficult, as it will determine the accuracy of the AFR.

From the above link, under the photo of "Chip Comparison", it seems the resistor values of that comercialise AFR isn't as describe by the author. So i am doubt of the author AFR's accuracy.

Also under the voltage table, the author mentioned that stoich A/F reading is 15:1. But as far as i am concern, it should be 14.7:1.

Please correct me if i am wrong...

 

[3R1C]

Well this is not a wideband AFR so it won't be that accurate.
At least it give u a rough idea of how ur car is runnig :)

 

[sky_kids]

mind tell where is 02 sensor?

new to injection car..

 

[sky_kids]

where to get those stuff
10 led in 1 row 1 wo
somemore the chip
wah..
any1 can help?
i'm having holiday from tomolo onwards

 

[3R1C]

Try to ask INDECIDED. i think he knows where to get the LED. however not sure about the chip as I'm getting it for free. just waiting for it to come into my mailbox. :D

 

[badguy]

where to get 12V LED????????????

 

[3R1C]

badguy,

The LEDs in the project is not 12v and you need a suitable resistor for that.

 

[acbc]

Use a 1k ohm resistor for LEDs.

LEDs are 3V only. Do not connect directly to 12V source!

 

[sky_kids]

any1 did tat??
who get d material d?

any1?
who did let me know..
i wana get 1 also

 

[3R1C]

sky_kids,

I've done mine and just waiting for the chip to come in so that it will work. I'll post pics of it but as I said, still waiting for the chip.

Pics will be here by tomorrow.

 

[3R1C]

The parts...

 

[3R1C]

Front view when it's done...the socket is for the chip that I'm waiting for...