Re: Re: Dual O2 sensor ideas...

From: jon@dakota-truck.net
Date: Sat Dec 14 2002 - 19:31:44 EST


"Mike Meyerhoff" <mike@mypants.org> wrote:

: I don't think it'd work by averaging :( . The 02 voltages jump all over the
: place. An averaged value would jump all over too, but have a diferent
: range.

: For instance (roughly)... if one sensor can read from 0.0 - 1.0 volts.
: When you average two sensors together you probably would not have many 0 -
: 0.2 and 0.8 - 1.0 readings so your range would be 0.2 - 0.8. That change in
: range might not work well with the computer.

   Hmmm, that's a good point Mike. If both banks of the engine were at
the same A/F ratio, averaging should work just fine, since the reason the
sensors jump around is the computer's constant adjustment of the ratio.
However, the whole idea of having 2 sensors is so that one side of the engine
doesn't lean out, so the very theory behind that kinda negates the whole
idea. (If we knew both sides of the engine were the same all the time
there would be no reason to use 2 sensors in the first place.)

  However, I suppose the argument cold be made that you're probably not going
to see .1 too often anyway, and under closed loop, the same could be said
for .9. Hmmm, I'd have to think about that some more I guess. :-)
(Anybody else have any opinions on it?)

: What might work better would be a setup where each sensor was read every
: other time, alternating. How you build that bit of electronics I have no
: idea, wrong engineering degree :)

  
   PIC project! (inside joke) ;-) I haven't given it a lot of thought
but I know I can do it easily with a microprocessor. Probably overkill;
it could probably be done a lot more simply with a 555 chip or something
along those lines, though I suppose using a microprocessor would make
changes to the circuit a lot easier (allowing you to program in software
instead of solder).

-- 

-Jon-

.---- Jon Steiger ------ jon@dakota-truck.net or jon@jonsteiger.com ------. | I'm the: AOPA, DoD, EAA, NMA, NRA, SPA, USUA. Rec & UL Pilot - SEL | | 70 Cuda, 90 Dak 'vert, 92 Ram 4x4, 96 Dak, 96 Intruder 1400, 96 FireFly | `------------------------------------------ http://www.jonsteiger.com ----'



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