O2 sensor led meter-K&N ref.

[Zublin, Bryan (SD-MS)]

It's incredible how much the aftermarket suppliers can charge for simple 
electronics.  I made one of these devices (also using the LM3914) for a 
friend after I saw similar products in catalogs.  It took me about a day.

So why hasn't someone come out with an inexpensive (around $300) generic EFI 
computer?  The price for existing aftermarket EFI computers is around $1000. 
 What's the parts cost for the EFI332?  Maybe someone could take it to 
market when all of the bugs are worked out.  This would be a great step for 
those of us looking for more performance.

Bryan Zublin
bzublin at gi.com
 ----------
From: owner-diy_efi-outgoing
To: DIY_EFI
Subject: Re:  O2 sensor led meter-K&N ref.
Date: Thursday, August 17, 1995 2:53PM

        You hit the jackpot with that one Robert!  K&N has marketed  an
air/fuel ratio monitor for several years that uses that very chip.  I
actually purchased one a couple of years ago for my 1986 FJ1200 motorcycle
@ almost $200, decided to take it apart, and found that they tried to
scrape the IC number off the chip.  Using a simple dissecting microscope
and some vegetable oil to clarify the number, I was able to identify the
chip as good ol' LM 3914.  Needless to say I was ticked-off at the fact
that I was able to reproduce the exact circuit for less than $6, including
all electronics except the 02 sensor (add an extra $30 for a single lead
sensor).  I thought of marketing the same product myself, since they
apparently don't have any patent or license protection on the circuit ( I
checked ), but "pirate" versions have been popping-up all over the place,
so I decided against it.  If you want to make your own 10 segment led meter
or larger, all you need to do is follow the info. in the spec sheet from
Digikey and pot it in colored epoxy or polyurethane for an attractive,
weatherproof, completely functional unit.  Total price ~$40 (including 02
sensor).


Sean Magnuson

Cornell University

Motorcycle Performance Nut