[Wbo2] Using the Bosch WB sensor with L1H1 circuit board

Fri Nov 11 02:55:03 UTC 2005

Wayne,

Here are some old posts on this subject. I think the
general conclusion was that DSP processing is needed
to get decent accuracy out of the Bosch LSU sensor.

A couple of people have mentioned that 

http://www.plxdevices.com/

makes a very good unit for this sensor.

Tim

http://thirdgen.org/techbb2/showthread.php?s=&threadid=248035

-----Original Message-----
From: wbo2-bounces at diy-efi.org
[mailto:wbo2-bounces at diy-efi.org] On
Behalf Of allen brown
Sent: Friday, March 04, 2005 5:31 PM
To: wbo2 at diy-efi.org
Subject: Re: [Wbo2] Bosch LSU4 with the DIY-WB

Considering the source not a surprising response. The
Bosch sensor has been made to work with the DIY-WB
design years ago. IIRC (it's in the archives) the
gentleman that did this lowered the heater voltage and
it worked. He was in Greece (help for a search).

Also, why not a junkyard sensor? For the price it is
well worth trying out. Absolute accuracy isn't always
a requirement. Much tuning can be accomplished with a
WB.

Al.

allen brown wrote:
> Considering the source not a surprising response.
The
> Bosch sensor has been made to work with the DIY-WB
> design years ago.

One of the first things we (Tech Edge) did when we
decided the L1H1 
was way overpriced was to connect the LSU up in much
the same DIY-WB 
circuit as the NTK. Sure, we got it to work, and it
gave some sort of 
readings that we could have worked out a new Vout Vs.
AFR table for. 
But I couldn't see the point of people spending time
and money 
building something that was going to give just an
"indication of AFR" 
- I mean, that's just what a zero-extra-cost
narrowband sensor will do 
for you - or, for a little more accuracy, a fairly
expensive NTK 
sensor and an inexpensive DIY-WB circuit.

At the time the NTK sensor jumped in price, I decided
Tech Edge had 
come to a junction, so I asked the question : do we
drop DIY-WB, or 
make AFR sensing a "proper" business? So, finding some
local people 
who had a similar interest, I put a lot of development
dollars into 
producing a professional quality microprocessor
controlled WB unit 
primarily for the LSU. And shortly after we released
that unit, we 
made it available as a DIY kit. We have sold thousands
of these 
version 2A0 kits (as kits, and many more as "prebuilt"
units). I have 
published the schematics for the 2A0 design, (but we
retain the 
unpublished firmware) and it is a very popular device.
But ...

It's important to realise that the Bosch LSU is
designed to be 
different to the Honda-NTK UEGO device. It really
needs to be 
controlled better to give similar results to the NTK.
But, if it's 
controlled properly, it has the potential to be more
accurate than the 
NTK.

>  IIRC (it's in the archives) the
> gentleman that did this lowered the heater voltage
and
> it worked. He was in Greece (help for a search).

In early 2003 I was in contact with the "Greek guy"
(Giannoulis 
Kafetzis) that did this, and provided him with a
little information to 
get him going. I can provide an email address if it's
not readily 
available in the archives.

> Also, why not a junkyard sensor? For the price it is
> well worth trying out. Absolute accuracy isn't
always
> a requirement. Much tuning can be accomplished with
a
> WB.

Sure, if you can get a junkyard part for a few tens of
dollars, but if 
we're talking around the $100 mark then I can't see
that the 
cost/benefit ratio is good. I'd stick with the NB
sensor or go with a 
field proven low cost design with a low cost sensor.
But if you want 
to go NTK ...

I'd suggest that Steve Nichols (see previous email
from Jurgen) is the 
person to get the sensor from if you really want to
use the "old" 
circuit.  I believe he sells them for US$120. (we sell
a connector kit 
for AU$9 that mates to it).

Final point: I'm not writing this in order to drum up
sales, but to 
provide an alternative view point on the cost benefit
ratio of the 
original DIY-WB design.

And, to those who, after all these years, think I did
something wrong 
in making the original OZ-DIY-WB design readily
available, and at a 
small cost - please don't put that forward as an
argument to otherwise 
unbiased people who couldn't give a damn, and are just
after honest 
accurate advice on how to get a low cost WB
instrument.

Peter.

PS. I don't intend to get into any discussions that
are otherwise 
ancient history, but I will respond to technical
questions about using 
the LSU sensor.

--- Wayne Macdonald <wmcdonal at optushome.com.au> wrote:

> Hi.
> I have one of the first DIY-WB circuit boards that
> was designed for the L1H1 wide band sensor.
> Can I adapt this circuit board to use the cheaper
> Bosch wide band sensors like the one found on the
> VW?
> 
> Thanks
> 
> Wayne
> 
> > _______________________________________________
> Wbo2 mailing list
> Wbo2 at diy-efi.org
> http://lists.diy-efi.org/mailman/listinfo/wbo2
> 

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