Changing output of WB O2 setup (Autronic)

[Glenn & Debbie Woodhouse]

I e-mailed FJO with the question a couple of months ago.  Below is their
response:

"I checked the 12-14.7 range and it appears our WBO2 controller has
approximately a 0.51 volt span over this range. What sort of resolution were
you hoping for? A 0.5 volt span into a 10-bit A/D should yield a resolution
of 0.03 AFR if my math is working correctly today. This is what our WBO2
controller uses to convert the analog reading to digital for sending out the
RS232 interface. Perhaps this would be an option for your system if it has
an unused RS232 serial input? Then you would have the AFR values directly
and not need to convert the analog voltages.

Hope this helps!

Thanks,
Fred"

So, the 0.5 volts is from 12:1 to stoich, not 11:1 to stoich but a little
crude extrapolation would indicate that 11:1 to stoich would be a 0.7 volt
range.  So as Fred from FJO mentioned, you want 10 or 12 bit a/d conversion,
which the FJO controller does for its digital output.  I forgot  that their
controller provides a 10 bit digital output along with the analog output.
This is a very nice feature that the NTK controller box does not support.

Glenn.

------------------------------

Date: Tue, 7 Aug 2001 13:31:06 -0500
From: Neil.Poersch at mts.mb.ca
Subject: Re: Changing output of WB O2 setup (Autronic)

Glenn,

Looking at the spec sheet for the analog output of the FJO unit it seems to
range from 1.25V to 2.5V for AFR's of 11:1 to stoich. This gives a voltage
swing of 1.25V.   Where did you get your info from?

Neil



>
For those interested in using a WB for forced induction tuning, thus being
primarily interested in A/F ranges from stoich to ~11:1, the NTK and FJO
controller boxes' output voltage only ranges about 0.5 volts.
<


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Date: Tue, 7 Aug 2001 22:01:48 +0200
From: =?us-ascii?Q?Jorgen_Karlsson?= <jorgen.m.karlsson at home.se>
Subject: RE: Changing output of WB O2 setup (Autronic)

Arghhh,

I think that we have to talk to the guys at FJO, the diagram I recived from
them suggest that 11:1 is more like 1.8V. They seem to send different
information to everyone...

You can find the diagram in incomming now, I named it: FJO WBO2 Calibration
curve.PDF


Jorgen Karlsson
Gothenburg, Sweden.



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