RE: (ET) sticky relays

["Elie, Larry (L.D.)" <lelie ford com>]

Actually, it's 42 nominal, 45 to 48 under charge.  The choice was because 
the absolute maximum without a GFI is 50V.  That I got from the head 
member 
of out team on the consortium.  The max droop voltage (due to lead
resistance) 
that they plan is 36 v at any load.  If that's not complicated enough, it
was 
originally planned with a 12/14V tap for existing devices.  Now (as of
March) 
the plan is a 5V (TTL like) tap for everything under the size of the
windshield 
wiper motors.  That choice was made because of pricing and packaging of 
power electronics, especially FET's and IGBT's.  It turns out that a 40V+
only 
system would cost MORE than a dual system because of all the little
actuators 
all over our cars; coils appropriate for 42V are so fine that displacement
type 
connecters (read cheap) can't be used.  The high voltage choice was for
wiring, 
and because we can't wind alternators beyond 120 amp at reasonable cost.  

BTW, GE has a presence on the consortium, but I have no idea why.  I have 
discussed the GE ET with our head member on the consortium (on another
matter, 
a patent for relay replacement) and he told me he actually asked about some
ET 
characteristics at a meeting.  GE doesn't remember much about the project.

Larry Elie
Ford Research


-----Original Message-----
From: MR23=Christopher Meier (Mtka, MN, USA) [mailto:mr23 worldspy net]
Sent: Tuesday, May 30, 2000 1:02 AM
To: snaugler earthlink net; Elec-trak; Neil Dennis
Subject: Re: (ET) sticky relays


That's 42 volts, not 48v.    36v nominal, 42volts under charge (via
alternator)
(compared to 12v and 14v).

Christopher M. Meier

----- Original Message -----
From: "Steven Naugler" <snaugler earthlink net>
To: "Elec-trak" <elec-trak cosmos5 phy tufts edu>; "Neil Dennis"
<wombat RealNS com>
Sent: Monday, May 29, 2000 5:00 PM
Subject: RE: (ET) sticky relays


> Neil and other GE folks,
> 36 V will only bite you if you are wet or if you puncture your skin and
> expose your internal wetness.  Internally we are all very conductive, but
> dry skin is not very conductive.
> The resistance of human skin is why Detroit is investigating 48 VDC as 
> the
> next automotive electric system voltage for internal combustion engined
> vehicles.  Road going EVs need much higher voltages to keep drive motor
> currents reasonable, so they have very dangerous voltages.
>
> Steve Naugler
>
>
> > [Original Message]
> > From: Neil Dennis <wombat RealNS com>
> > To: Elec-trak <elec-trak cosmos5 phy tufts edu>
> > Date: 5/29/00 2:36:34 PM
> > Subject: (ET) sticky relays
> >
> > I just had an hour or so debug session with my E-12.  I would drop into
> > first speed and keep going when I raised off the seat opening the 
> > safety
> > switch, also the brake would not shut down the motor.  After reading
> > about welded solenoids here I thought OK that is the problem - so after
> > much checking and reading schematic, I traced to "2RTN" not traveling
> > far enough to open the normally open contacts.  After replacing with a
> > spare that didn't close properly so I still had to do some adjusting,
> > now things work right.  Incidentally, open the disconnect when 
> > fingering
> > around in the control box, 36 volts does bite a little. (experience)
> >
> > wombat
> >
>
>
>
> --- Steven Naugler
> --- snaugler earthlink net
> --- EarthLink: It's your Internet.
>
>
>