Questions about EGOR

[Ludis Langens]

<garfield at pilgrimhouse.com> wrote:
> Since most all the devices, excepting the idea I mention below,
> can be had in surface mount, the entire EGOR board is likely gonna fit
> in something WAY shorter than a 40-pin 0.6" DIP. Yep, you heard me
> right, it's that small.

Cool!  (Thoughts of putting an EGOR inside of a GM MEMCAL - along with
the EPROM, limp-home calibration, and knock sensor filter... probably
not a good idea though.)

> My own preference would be that you'd use 12v and this
> regulator, cuz the regulator spec'd in the design is a special one for
> automotive, that has all kinds of protection, [...]
> The precision references run off this 5V, so I'd want a
> good regulator looking over them.

I'd probably be using EGOR inside of an OEM ECM which already has a
power supply with an alphabet soup of features.  Plus it turns itself on
and off as needed.  This supply is also used as the upper end reference
for the AtoD.

> It's so low, I
> didn't bother adding it up, but I'd say way below 50mA @ 5V. But again,
> I'd prefer you going off B+ like another other sensor, rather than a
> slave off the ECM, [...]

50mA?  No problem.  BTW, most of GM's sensors run off of 5V.  (CTS, MAT,
and some switches from the same supply as the CPU.  MAP and TPS from a
second 5V.)

> If the Ion pump connector gets
> shorted to gnd, you're gonna spill 13mA at most into the crapper, and
> WAY less in the case of the VsCell bias, so not to worry about EGOR
> hemorrhaging.

OK, with a 13mA short circuit current, it could safely run off the main
5V supply.

> >Is EGOR's 0 to 5V signal output range a "natural" range?
>
> "Natural"? that's a new one on me.

What I meant is this:  Is there some physical phenomena requiring the 5V
range?  For example, an old fashioned O2 sensor has a ~1V range 'cause
that's the way it works.  Whereas 74xx TTL runs on 5V because some
standards commitee decided so.  In other words, are you applying a 5V
range to the sensor?  Or is it from an intermediate node which swings
rail to rail?

> I'd say any system that
> expected ANY output to be able to drive 1K into 5V is really asking for
> disgusting jokes about their mama. That's pretty low impedance.

No kidding!  That's why I asked.

> Course, you gonna pay for that with increased supply
> load, but it's still only another 10% of budget, so no sweat.

The increased supply load comes from the other devices supply, not EGORs
supply.  (Unless EGOR uses an output transistor with a beta of 1.)

> >Can EGOR be designed with an output range of about 1 volt?  This would
> >allow EGOR to directly drive an ECM's existing O2 input(s).  (It's a
> >trivial matter to edit a PROM to handle a different O2 input voltage
> >profile.)
>
> NO, this ISN'T gonna be possible, and for an even better reason than
> just "levels" issues. If you read the previous posts, the output of
> these Ion Pump interfaces is in NO way similar to a stock O2 sensor.

So I guess I'd need to put a 5:1 resistor divider on EGORs output, run
that to the standard O2 input, and change the 4 or 5 PROM bytes needed
to deal with the different voltage profile.

> I can't take
> the space AGAIN to outline this; suggest you climb back up the thread a
> day or two's worth [...]

Well, you haven't described EGOR's internals or the exact sensor
operation yet.  (That's OK - I'd rather you post confirmed results than
educated speculation.)

> Bzzzzzzzt. I can't cite you chapterNverse of the year/model of the VX
> Civic, but I've BOUGHT sensors for our year/model range IN CALIF, and
> they ARE 5-wire and suitable. What exactly are you after here? I've
> ALREADY posted the Honda part number. You wanna argue with THAT, or
> what? I don't get yer drift, mate.

I was just repeating what the repair manual said.  I'm sure you can buy
parts for all sorts of non-California cars in California.  (The reverse
isn't always true - just try to find a California spec cat in the middle
of Wyoming.  I got to drive to Montana with an open exhaust.)  The point
is that I'm not likely to find one of these Civic's in a junk yard. 
They are at least 5 years too new - unless they got run over by an 18
wheeler.  And even then, it would have to be an out of state Victim er.
Civic.


Have you made any progress with figuring out the calibration resistor? 
Anyone changing an O2 sensor in the pits during a race would like not
having to recalibrate EGOR.  Same with anyone with an ailing BelchFire
V11 driving through Podunksville.


You've implied that the NTK box does nothing with the O2 heater.  The
Honda schematics imply that they do control the heater - perhaps to
regulate the temperature.  Any thoughts on this?


If there is ever a group purchase of sensors, it should include a group
purchase of the mating wiring harness connector.

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