I take it that your car isn't injected, then the typical o/p voltage of a
lambda "oxy" sensor at Stoichiometry "air fuel ratio of 14.7:1" is 0.45V. I
have seen drawings for sampling this to give a graph of "working
conditions". If all you want is, running rich then use a comparator. The cct
I've seen has a 1M I/p.

>At 08:50 PM 10/8/98 -0700, you wrote:
>>I have installed an o2 sensor on my car and want to build an LED output
for
>>it. I was thinking that I could just drive the LED through a unity gain
amp,
>>maybe a small FET or bipolar? And the output of the O2 sensor would light
>>the LED at .67 Volts, showing me a rich condition? Do LEDs light at .67
>>volts? Would a small signal bipolar have enough impedance for an O2
sensor?
>>Any help on this would be welcome. I want this to be very simple and fast
to
>>build.
>>Thanks
>>John
>>
>
>http://www.bobblick.com/
>