O2 sensor Voltage

[Mike (Perth, Western Australia)]

At 05:40 AM 8/03/2000 PST, "mike mager" <mikemager at hotmail.com> wrote:
>"Steve Leonard" <gsxr1300 at hotmail.com> asked:

>A simple single-supply operational amplifier could add an offset Voltage to 
>the EGO Voltage, or could effect the EGO Voltage by a ratio.  "How lean can 
>you go", we wonder?

Correct me if I'm wrong (can't recall rich/lean direction) but if the
output voltage goes low(er) to indicate richer, then all you need is
a voltage divider or even (if the o/p impedance of the sensor is high)
a series resistor.

If its the other way around - higher voltage = richer then all you need
is a small pullup resistor to a convenient supply rail to 'lift' the
sensor voltage - a series resistor to the sensor would be a small protection
and it also depends on the O2 output impedance.

In essence with a bit of investigation easier then an opamp, though
admittedly an opamp does have a nice high i/p impedance and a single trim pot
can make the offset go +ve/-ve from span to span with some cal for checks.


Rgds ~`:o)

Mike Massen         Trading as "Network Power Systems" and "Network Computers"
Perth, Western Australia  Ph +61 8 9444 8961  Fx +618 9264 8229 (fax -> email)
Products/Personal/Client web area at http://www.wantree.com.au/~erazmus
 (Current pics - trip to Malaysia to install equipment in jungle power site)

Some say there is no magic but, all things begin with thought then it becomes
academic, then some poor slob works out a practical way to implement all that
theory, this is called Engineering - for most people another form of magic.

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