Lucas magnetic sensor

[Bruce Plecan]

-----Original Message-----
From: Stowe, Ted-SEA <StowT at PerkinsCoie.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Sunday, November 15, 1998 4:27 PM
Subject: RE: Lucas magnetic sensor


>Bruce, I checked it with a DVM, it is a coil, with a tap, I get about 22
>ohms in either direction. So when the magnet passes by it, I would >guess
that the impedance changes, I am trying to find something >simple to make
this put out .5 ?

That low of resistance is beyond anything I've done, that question is
for one of the EE here.

> or whatever the gm hall effect sensor did. I also have an
>Allison optical pickup for that distributor. that is pretty simple, I
>could probably just have a transistor driver for the GM ignition >module,
it would appear that the optical guy, (which has a slotted >wheel for the
rotating part), would switch on +12, that would >probably be bad for the
module. or I suppose a simple resistor >network would drop that down.
>
>I would rather have the magnetic sensor rather the optical guy, but I
>won't argue with getting it running.

If it was me, I'd use the Allison Optical.  Cause they last, and rarely
go bad.  I'd reverse engineer the module to see what the + is to the
"head", ground, and see what the return signal is.  Then all you
have to do is figure out the power supply, and how to light a LED.
Once you can light a LED (using like a 1K resistor) you have your
dissy signal.

Just for instance if it runs on 5v then a 7805 for a power supply.
HTH Bruce
>thanks,
>Ted.
>
>-----Original Message-----
>From: Bruce Plecan [mailto:nacelp at bright.net]
>Sent: Wednesday, November 11, 1998 11:26 AM
>To: diy_efi at efi332.eng.ohio-state.edu
>Subject: Re: Lucas magnetic sensor
>
>
>
>-----Original Message-----
>From: Stowe, Ted-SEA <StowT at PerkinsCoie.com>
>To: 'diy_efi at efi332.eng.ohio-state.edu' <diy_efi at efi332.eng.ohio-state.edu>
>Date: Wednesday, November 11, 1998 2:15 PM
>Subject: Lucas magnetic sensor
>
>Hello,
>using an ohmmeter trying reading the pickup if you get the same readings
>when you switch meter leads then, I'd assume it is just a coil.  If the
>resistance is like 800-1K, then just wire it as is to the gm ignition
>module.
>Again with no wiring to look at this is justa guess, so no warranty implied
>or expressed.
>Bruce
>
>
>>Hi, I need a bit of help this morning.
>>
>>I have a Lucas distributor with what I thought was a hall effect sensor,
>but
>>it appears that it is a coil with a center tap, (3 leads).
>>
>>I need to trigger a gm ignition module with this, so I imagine I need some
>>type of buffer for this. I have no idea if hall sensors were edge
triggered
>>or not, or if this Lucas sensor is or not. I suppose I could just have a
>>simple pull-up to a stabilized voltage source of ? and generate a pulse. I
>>also have a Lucas optical sensor if that would make a difference, but I
>>don't think so. has anyone ever done this or does anyone have any good
>ideas
>>?
>>
>>thanks, Ted Stowe
>>
>>-----Original Message-----
>>From: Albert Grippo [mailto:grippo at jlab.org]
>>Sent: Wednesday, November 11, 1998 4:57 AM
>>To: diy_efi at efi332.eng.ohio-state.edu
>>Subject: Re: ? on Mr Hall Effect
>>
>>
>>  The Hall sensor I am using has 3 pins: VDD(+5 or +9 V), OUT,
>>  and GND. I connected a 5K pullup resistor between VDD and OUT,
>>  and a .1 uF decoupling cap beteween VDD and GND. To use it
>>  I glued a ceramic button magnet to a distributor, mounted
>>  the Hall sensor over the magnet, and put a slotted steel wheel
>>  in between the two.  When the solid part of the wheel is
>>  over the magnet, it shields the field from the sensor and
>>  you read VDD volts on the OUT pin.  When the wheel is
>>  turned so the slot exposes the magnet, you read 0 volts. It
>>  is not sensitive to motion, just to whether the magnetic field
>>  is exposed or shielded. I am using it to determine the no. 1
>>  cylinder. One last thing, the magnet south pole goes toward
>>  the sensor.
>>
>>   -Al Grippo
>>
>