CHEAP Wideband kits!

I know of several who use these with great success. I'll be getting one as soon as they're available with displays.
 
One of Jaycar's air fuel readout is numerical, does anyone know the type of O2 sensor that would work with this? Is it specifically a wideband O2 sensor?
 
I'm definately interested in one and possibly two, so lets see if we can get anybody else in.

"JAW is the lowest priced wideband oxygen sensor reader ever.
Product Features:

$45 DIY Kit: Without Display
$70 DIY Kit: With Display
$60 Assembled: Without Display
$90 Assembled: With Display
Uses the inexpensive Bosch LSU Wideband Sensor.
Accuracy to 0.01 Lambda.
2 programmable outputs
Free Air Calibration
Real-time datalogging
User selectable refresh rate of 8-255 [hz] for digital display
Reads from 0.69 [Lambda] to 2.33 [Lambda]
Reads from 10.18 [AFR] - 34.28 [AFR] "

http://14point7.com/JAW/JAW.htm

"Shipping is a flat rate of $10 for orders up to $100, $20 for orders upto $200, and $30 for orders upto $300.

For group buys of 10 of more JAW units there will be a $5 discount. For 10 or more Display units there is a $2.50 USD discount. Shipping will be $30 for the entire order, I am no longer doing individual shipping for group buys. Please email me "toalan@14point7.com" for group buys."
 
Hodgie1013":35hxpwqa said:
...
"Shipping is a flat rate of $10 for orders up to $100, $20 for orders upto $200, and $30 for orders upto $300.

For group buys of 10 of more JAW units there will be a $5 discount. For 10 or more Display units there is a $2.50 USD discount. Shipping will be $30 for the entire order, I am no longer doing individual shipping for group buys. Please email me "toalan@14point7.com" for group buys."
Click to expand...
Looking at the group buy info, it looks like it wouldn't a good deal unless everybody involved lived close enough to avoid shipping them again, since he'll only ship to one location.

Or am I missing something?
 
Just got through downloading their software and info, and checking it all out. I am WAY impressed with this!

Get: Non-display DIY kit = $45
Get: Shipping for the above = $10
Get: Bosch sensor via Amazon = $44.39 (free shipping!)
Get: Wiring to connect the sensor to the JAW kit = already have laying around
Get: 8-18 Volt Voltmeter = already have one laying around

Do: Solder and wire it all together
Do: Enter the A/F ratios as straight voltage outputs, ie: 14.7 AFR = 14.7 volts. Want to compress the upper and lower ends so as not to over-run the gauge, as in: AFRs greater than 18 are all = 18 volts, and AFRs less than 8 are all = 8 volts. Or, I can go get a volt gauge with a wider range, like 24V, or I can program the output to whatever I want.

So...for 61 cents under $100, I can have a wideband gauge in my car that matches the existing oil, temp, and volt gauges. (It's marked "volts", but so what? Or, it's easy to open up a gauge and relabel the face.)

Am I missing anything here?
 
jamyers":35m38e9d said:
Get: 8-18 Volt Voltmeter = already have one laying around

Do: Solder and wire it all together
Do: Enter the A/F ratios as straight voltage outputs, ie: 14.7 AFR = 14.7 volts. Want to compress the upper and lower ends so as not to over-run the gauge, as in: AFRs greater than 18 are all = 18 volts, and AFRs less than 8 are all = 8 volts. Or, I can go get a volt gauge with a wider range, like 24V, or I can program the output to whatever I want.

So...for 61 cents under $100, I can have a wideband gauge in my car that matches the existing oil, temp, and volt gauges. (It's marked "volts", but so what? Or, it's easy to open up a gauge and relabel the face.)

Am I missing anything here?
Click to expand...


Am I missing anything here?

Unfortunately, yes.

Electric instruments used in very old cars had a movement similar to that used in a handheld analogue multimeter. The meter responds very quickly to input change and depending on the quality can have an accuracy of a few percent.

Later OEM gauges and most aftermarket gauges have a movement that comprises of a fine wire wrapped around a bimetallic strip which bends when heated and moves the needle.

The higher the input voltage
the larger current through the coil
the larger the heat generated in the coil
the hotter the bimetallic strip
the more the bimetallic strip bends
the further the needle moves.

There is an appreciable time lag between a change in meter terminal voltage and the corresponding movement of the needle. Also they are not particularly accurate and should be viewed as indicators rather than precision instruments.

More senior (read older) drivers will remember the days when the fuel gauge jumped immediately after the ignition was switched on, and the needle responded to fuel sloshing in the tank during braking and spirited cornering. Modern fuel gauges with a thermal movement take some seconds to respond to input changes.

A voltmeter with thermal type movement would not respond quickly enough to changes in the AF ratio as the engine load changes, at the best it would be an average value. They just are not accurate enough for this purpose.

There are a few aftermarket suppliers of magnetic movement gauges (Classic are one I know of), but these will be expensive and quite likely not match the face style of your existing gauges.

If you already have a voltmeter available, the first step is for you to test the type of movement it has. Connect wires to the terminals then touch them to the battery terminals for a couple of seconds. The thermal type will creep up and slowly return to zero while a magnetic type will respond immediately.

Although it would not match your existing gauges, a display made from a bunch of suitably coloured LEDs arranged in a bar formation would be inexpensive, accurate and easy to read without having to peer at small numbers.
 
Well, it's a bit more complicated than I first thought, but I still think it's very do-able once I learn a little about electronic stuff.

Two Issues:

FIRST: The problem with my original 8-18V Voltmeter/Gauge idea is that the JAW outputs only range from 0-5 volts, which is apparently the new standard for computer/automotive electronics, including Air/Fuel gauges. This would be fine, except I can't find a 0-5V Air/Fuel gauge for less than $80, which defeats the whole purpose. What most guys are doing with the JAW is using a digital readout and programming the output to divide by 10, which gives the AFR with the decimal off one place to the left - so you ignore the decimal.

But I don't want a digital readout, I want a gauge with an honest-to-gawd needle.

So...I asked Alan To (the JAW guy) about it, and here's what he said:
Hi, You could use an op amp to make an amplifier for the signal, however you will have to supply the op amp with atleast 18v for power, unless you have an 18v source you would need to use a step up regulator.
Regards, Alan To
Click to expand...
Cool.

SECOND: The software that comes with the JAW allows datalogging the AFR, RPM, and two other inputs (like a MAP and TPS). Way cool, however: it wants (again) 0-5 volt inputs for the RPM, and both my old cars have tach drive outputs that are based on 12 volts. Again, I asked on the JAW forums, and got this reply:
Hi, why not use a simple voltage divider? Works fine with my JAW!
Carsten
Click to expand...

OK, I'm glad for the direction, but I'm also a complete electronics-newbie, and have only a vauge idea what an "op amp," "voltage divider," and "step up regulator" are, much less which parts to go buy or how to hook them together.

Anybody here who knows electronics willing/able to help a complete electronics-newbie out with this?
 
Here's a schematic that Carsten posted for a voltage divider.

Revs_Signal.JPG


Looks like a trip to radio shack... (?)
 
jamyers":20k51kzy said:
Well, it's a bit more complicated than I first thought, but I still think it's very do-able once I learn a little about electronic stuff.
Click to expand...

All the info you have been given is correct, but not particularly helpful unless you are a person who regularly wields a soldering iron.

It is quite easy to generate 24V from 12V with a step up invertor, then use that to power an op amp which will rescale the 0-5V JAW output to 0-18V for the gauge……provided you have the necessary skills, time, and equipment at your disposal.

Imagine for a moment that the roles were reversed.

An electronics wizard with very limited mechanical knowledge comes to you with his classic car and says something like, I want a larger engine that looks exactly the same as the standard engine, is that possible?

You respond, that is real easy, bore it out to the limit, offset grind the crank, then fit shorter rods or custom slugs! The electro-wizard smiles politely but is utterly confounded.

If you want to delve into the world of electronics as a learning experience then go for it, but if you are really only interested in this particular item it would be better to find a tinkerer who likes playing with these one off projects, the type of person who likes the smell of solder in the morning!
 
Trivial to do, for someone who knows what they are doing (like me).

If you aren't familiar with electronics, it will be a steep learning curve. I am perfectly willing to coach you on how to do it however.
 
I am extremely challenged when it comes to electronics so the question: How does this device wire up to a carbed vehicle? (Like the one in my signature).
 
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