DDL update (was: braindrizzle)

[Bernd Felsche]

bcroe at juno.com tapped away at the keyboard with:
> All these are good thoughts deserving plenty of
> investigation and development.  The ISSUE here
> is, shall we NOW introduce something that lots of
> people need and is ready to go, or shall we put it 
> on hold for at least a year while other more exotic 
> functions needed by a minority are developed.  I
> say NOW.  

There might be parallel development going on.

> I favor this minimum WB board with bar graph display
> plus universal voltage scaling circuit, because my
> package has been in use since this summer by
> a far better engine tuner than me.  His praise of the
> setup runs for pages, but in a word, this is the way 
> to go.  I think everyone ought to have that option, now.

I've just updated the DDL (Direct Digital Lambda) web pages...
DDL is one of my low-priority (hobby) projects.
  http://bernd.felsche.org/tech/EFI/vapour/DDL.html

One could program the AVR to output a pulse-width modulated signal
according to lambda, for feeding straight into a bar-graph display
chip such as an LM3925 (I think that's the linear one) via a
capacitor and resistor network. The display could then be mounted
remotely.

The major change is in the proposed pump cell drive. Also, the
recognition of the common pin between cells on available sensors was
an issue that needed to be investigated.

I'd also ordered myself an SAE proceeding book (Electronic Engine
Controls 1999) for Christmas 2000 and when it arrived early in 2001,
I found the very first paper discussing a digital controller for NOx
sensors; which require sense currents in the nano-amps.

So there's hope it might actually work! :-)

Ref: SAE 1999-01-0202
Long Term Stable NOx Sensor with Integrated In-Connector Control Electronics
	Nobuhide Kato and Nobuyuki Kokune: NGK Insulators
	Bertrand Lemire and ime Walde: Siemens AG

The project is not quite on hold ... awaiting a sensor for testing
and a whole bunch of time! I have no firm time as to when I'll have
a running circuit.

Recent discussions about AFR simulation using various gases as well
as the NGK data sheet have been helpful.

-- 
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