Re: O2 Sensor monitors

[Dave Lawson <dlawson@ball.com>]

Steve,
>You are right Scott ... there really isn't that much to making an O2 sensor
>monitor display.  I haven't checked lately, but National Semiconductor used 

>to make an IC that would drive a bar-graph display based on an analog input 

>level.  ...

We have designed one using the national chip and a 10 segment LED display. 
Never got around to using that one though. I now have an Air/Fuel LED 
bargraph which I bought from JC Whitney for around $30. It is made by 
Cyberdyne and works fairly well. Comes in a VDO size round gauge housing 
whose face is black until it is powered. It is simple to hook up, 3 
wires12V, Gnd and O2 voltage. It is designed with the high impedance input 
and it doesn't affect the O2 signal going to the ECU.

Also about a year ago there was an article in the UK magazine Fast Car(I 
think this was the title) which had a DIY article on building one of these 
LED meters. They found a 10 segment LED display which had the national chip 
built into the card. All they did was to tweek the input signal and the 
thing was working. Pretty neat.

>Glen, it sounds like you may have one of these doo-dads in your car.  What
>sort of things do you notice while you drive?

I wanted one to watch and verify that I was running on the rich side when 
the boost is cranked up. I now know I am in the rich range under boost and 
have only seen it go into the lean range while crusing and idling.
 -
Dave Lawson  dlawson@ball.com