home made wideband a/f gauge

[Module Unknown]

I found myself home on a friday night with nothing to do and thought it would be a perfect opportunity to start putting together a custom display for my LC-1 wideband. Of course I already had this planned and bought the parts from eBay.

If anyone is interested, here's what you'll need.

Mini Red LED DC 100V Digital Volt Voltage Panel Meter ($10) (if the url dies later, search for that on ebay) ...just feed this sucker the output from the LC-1 which I can program to display correctly on here.

and

5V 7805 Power supply regulator gd4 Digital Panel Meter ($11) (if the url dies later, search for that on ebay) ...used to output 5V that the display requires for power.

Anyway, the reason for this is that I'm not a fan of having gauges scattered throughout the cockpit, a-pillar, etc. and this shouldn't draw attention from passers by or people peeking inside the car.

Sooo, here's the panel installed!

http://img.photobucket.com/albums/v225/moduleunknown/dsm/P1010038.jpg

http://img.photobucket.com/albums/v225/moduleunknown/dsm/P1010036.jpg

Tomorrow (if I get around to it), I'll have to install the LC-1. The 02 sensor bung has already been welded on my downpipe so the rest should be cake!

Just thought I'd share, and maybe give others some ideas.

 

[Killa_dsm]

Wow, this seems really interesting. Keep us updated on how it works out for you.

 

[thekellbeast]

There was talk of doing this in another thread about widebands, but I don't remember there being any install pics.

Looks good so far, this is something I'll have to copycat when I get a wideband. Don't worry though, it won't be for a while.

 

[slammeddsm98]

That looks real good. I like how clean it is.

 

[THE REAL DEAL]

are you going to post up pics of how you're wiring the lc-1 to that? if you can show us that, im gonna try this.

 

[OverBoostinGST]

That looks awesome bro!

 

[bojanglesracing]

I though I seen it somewhere but can seem to find it. IF it can be done can someone show me where i can find it. I tried a search, But i guess i am looking up the wrong word. I need to know what all i need and how to put it together.

 

[Module Unknown]

I had posted something like that a while back (for building a display), only it didn't quite work out as I had hoped. I did figure out the problem though.

Here's what you'll need:

Innovate LC-1, using the programmable analog narrowband simulation output
0v-2v digital panel meter that shows two decimal places.
A voltage regulator IF the digital panel meter requires less than 12v.
Program the output of the LC-1 to 1v=10:0afr, 2v=20:0afr

My original problem was that I bought a volt meter display that read from 0v-99.9v. The problem there is that when the wideband would read say 14.7, the analog output would be 1.47v, in which case my display would read 1.4. So in other words, totally useless. Now if you had a volt meter that would display two decimals places, you could see 1.47 which would actually be "14.7afr". That being said, it's also possible to find a display that reads to two decimal places and allows you to select where to place the decimal. That would be the optimal display to use. But, after realizing I bought the wrong display, I quit the project. I can still monitor using my laptop and/or dsmlink (when I install it).

 

[bojanglesracing]

Where can you get that?

 

[Elvenhome21]

ebay, $160 with o2

 

[96gsdsm]

I made my own accurate to .001 for $60 with a Blue LCD screen.

This was like 2 years ago... I'll try to find a schematic.

It's gotta be in the garage on top of one of my piles of paperwork somewhere.

 

[Eastwood95]

did you find anything yet?

 

[Eastwood95]

you never mentioned it but did you finish installing that? How did you hook everything up? Total cost of all parts? and let us know how you like it....!

 

[96gsdsm]

Ok.... here's what I used...

-3.5 digit LCD display & backlight
(www.lascarelectronics.com/PRODUCTS.CFM?STOCKNO=SP 400-BLUE&CFID=14116506&CFTOKEN=86363796)
-Enclosure www.newark.com/jsp/Enclosures,+Comp...M-22+BLACK+KIT/displayProduct.jsp?sku=93F9932)
-1% tolerance resistors.... 220k(4), 470k(2), 100k(2)
-lengths of 22 gauge wire in 3 diff. colors (about 3') each to be safe,I'll say Green Red and Black
-Circuit board (Radio Shack part # 276-148)
-Voltage Regulator (Radio Shack part # 276-1770)
-Heat Sink (Radio Shack part # 276-1368)
-4-40 screw to secure regulator to heat sink (hardware store)
-Heat Sink compound (Radio Shack part # 276-1368)
-Electrical tape.

Tools Needed

Soldering iron
60/40 rosin core solder (Radio Shack part # 64-008)
Flux (Radio Shack part # 64-021)
Wire strippers/cutters
Multimeter
Drill
Dremel w/cutting bit
Knife

WHAT YOU DO

Fit the display and heatsink into the enclosure. You have to cut the front and rear panals to get it to fit. Measure, cut, fit. Your also going to need to drill a 3/16" hole in the back panel for the wires to exit. Your gonna need the dremel to fit the display over the main enclosure body, it's gona be a tight fit.

Cut the wire
(1) 3" green
(2) 3" red
(4) 3" black
(1) 1' Black
(1) 1' Red
(1) 1' Green

Strip, flux, & solder as shown in the pic link below
The 3" wires get connected withen the enclosure and the 1' ones go through that 3/16" hole you drilled.

The long red is your switched +12v
The long black is your ground
The long green is your o2 senser wire

Use a Knife to score the circuit board into 4 equal pieces and break it apart.

Wipe Heatsink to the back of the voltage regulator and screw it to the heatsink.

Assemble the circuit boards as shown in the links below.

Wire the display, voltage regulator, and circuit toghether as shown in pic #1

BEFORE YOU SCREW IT TOGHETHER YOU MUST CALIBRATE THE GAUGE
build the divider circuit exactly like you did the gauge. This will effectively step the voltage down from +12v to around 1 volt for the A/F gauge to read. Hook up the multimeter, A/F gauge, Power supply (+12v car battery) and divider circuit as shown in pic #2

Connect the power supply and the A/F gauge should turn on. The display should show a number around .8 to 1 volt. Use a tiny screwdriver to turn the calibration screw in the back of the LDC display until it matches as close as possible to the mulitmeter. it may fluxuate +/- .001, this is normal. Get them to match withen +/- .002V.

Assemble the Enclosure, wire in accordingly, and enjoy.

The link to the pic is ... http://i91.photobucket.com/albums/k309/littleniky006/HomemadeAFRatioGauge.jpg

Have fun

..... sorry it took so long... I found it under a buncha junk when I was cleaning the garage out.

 

[96gsdsm]

Been using it, along with an EGT gauge to tune with for about a year with no complaints.

It does fluctuate up and down like a normal narrow band.... but at WOT it's dead on.

 

[Urban_S]

Very cool. I wanna try this.

 

[mattdev]

Sorry to bring this dead thread back but I have some important information to add.

This is how I did the gauge...

( 3 1/2 ) Digital Red LED DC 0~±20V Volt Panel Meter (search on eBay)
5v Voltage Regulator (Radioshack #276-1770) Here

This 20v display SHOULD fix the problem Module Unknown has with the 100v Display. It is tuned for finer voltages instead of higher voltage applications.

 

[Defiant]

Pelican Technical Article: Building an In-Dash Air-Fuel Monitor

 

[gtseviper]

Hey, I have a question about the 5v regulator. I don't want to make assumptions about it being face up in the diagram, so I was wonder which side is input and output of the regulator in your diagram
thanks