Here is a link about the use of hall effect sensors for linear positioning
systems:
http://mariottim.interfree.it/doc11_e.htm
A Hall effect sensors output varies with the strength of the magnetic field
- in other words if you change the magnetic field you change the output. In
this case depending on the design it is probably designed as a pair of
sensors designed to screen out spurious magnetic fields BUT I wonder what
happens when you get a strong external magnetic field in the vicinity of the
sensors such as a magnetized steel strip as in a shoe arch support, stiletto
heel core, steel toecap etc.
Bob send me that system diagram soonest please before I have to do some real
work.
I have two Toyotas and was seriously thinking of wiring a kill switch into
the dashboard to break the feed from the fuel pump (which is generally easy
to get to since it is normally wired through the oil pressure switch (the
rational being that no oil pressure - you don't want the engine to run)
John Burke
(408) 515 4992
-----Original Message-----
From: John Burke [mailto:[log in to unmask]]
Sent: Thursday, March 18, 2010 2:54 PM
To: 'TechNet E-Mail Forum'; 'Bob Landman'
Subject: RE: [TN] More on Toyota
Importance: High
You have GOT to be kidding - they use hall effect sensors and magnets to
detect where the pedal shold be!!!!!!!!
Does any one here know if the people experiencing these issues happen to be
wearing steel toe cap boots?
Best regards,
John Burke
(408) 515 4992
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Landman
Sent: Thursday, March 18, 2010 2:43 PM
To: [log in to unmask]
Subject: Re: [TN] More on Toyota
Yes, it's a whitewash job, IMHO. I invited Dr Gilbert to our weekly tin
whiskers telecon last week. He was very humble and forthcoming on what he
knew and what he did not know.
He shared pictures of the APP (accelerator pedal module) which has SMT
resistors and caps and a small SOIC package that converts two redundant Hall
sensors that the magnets attached to the pedals move by. That results in a
1-4Vdc signal. Tin plated connector soldered to the board. Plenty of
locations for whisker shorts to do what Toyota's so-called expert said
"can't possibly happen".
If you would like to see the pictures and his technical report I'd be happy
to share them with you.
Bob Landman
H&L Instruments, LLC
Sent from my iPhone
On Mar 18, 2010, at 12:48 PM, Chris Mahanna <[log in to unmask]>
wrote:
> Has anyone else reviewed the Toyota slideshow and related PR on the
> Dr. Gilbert debunking?
>
> http://pressroom.toyota.com/pr/tms/document/Exponent_ProfGilbert_8Mar1
> 0.pdf
>
> As part of their "defense" they have totally laid-out the fault tree
> and required sequencing.
> Assuming that it is an under-hood box, with a little material and
> process information (like finish, solder, laminate, compliant pin?) it
> appears to me to likely be a quick FA.
> The fact that there is complete silence about any (IMO obvious) FA
> hypothesis is very intriguing.
>
> Although I have no specific information!, I think it highly unlikely
> that Toyota doesn't know the root (electronic) cause for at least some
> of them.
> If Michael Pecht or one of my competitors has their hands on a faulty
> unit the public should know the answer soon enough. If not, it
> probably means tort beat quality one more time (aren't they supposed
> to work in consort!?)
>
> I think it will be very interesting to see how the legislators and
> regulators handle such a situation.
>
> Chris
>
> ______________________________________________________________________
> This email has been scanned by the MessageLabs Email Security System.
> For more information please contact helpdesk at x2960 or
> [log in to unmask]
> ______________________________________________________________________
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 15.0 To
> unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt
> or (re-start) delivery of Technet send e-mail to [log in to unmask]
> : SET Technet NOMAIL or (MAIL)
> To receive ONE mailing per day of all the posts: send e-mail to
> [log in to unmask]
> : SET Technet Digest
> Search the archives of previous posts at:
> http://listserv.ipc.org/archives Please visit IPC web site
> http://www.ipc.org/contentpage.asp?Pageid=4.3.16
> for additional information, or contact Keach Sasamori at
> [log in to unmask] or 847-615-7100 ext.2815
> -----------------------------------------------------
>
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0 To
unsubscribe, send a message to [log in to unmask] with following text in the
BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or
(re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet
NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send
e-mail to [log in to unmask]: SET Technet Digest Search the archives of
previous posts at: http://listserv.ipc.org/archives Please visit IPC web
site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
ext.2815
-----------------------------------------------------
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask]
______________________________________________________________________
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
|
