24 May
2009
24 May
'09
2:41 a.m.
----- Original Message -----
From: "Charles H Dickman" <chd_1 at nktelco.net>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Saturday, May 23, 2009 3:19 PM
Subject: Re: Anyone heard of a North Plug or IBM wire relays ... Re:
Jonesplugs, or similar sorts of plugs
William Donzelli wrote:
Hi Chuck,
Yes, pictures please.
--
Will
http://www.chdickman.com/IBM/490-0056/
My recollection was a little fuzzy on some details. The wiring is made up
of wires with crimp terminal plugs on the ends and each relay socket
terminal has two receptacles for the wires. The relay moving contacts are
actuated in a group by a plastic piece connected to the armature. The each
moving contact consists of two fine (#30) gold wires. The narrow relays
have 4 Form-C contact, the intermediates 6 and the wide ones 12.
The plug and terminal strip are not part of the base socket frame, but
were likely made by us and then added to the frame.
The date code on the chassis says 1976, so this is probably the last one
built and then cannibalized for relays to send to customers.
After looking at it, I wish that it still had the full compliment of
relays. It might be interesting to make something out of it.
-chuck
From your img_4676.jpg I would say those are exactly
what I was trying to
describe, including the crimp terminal plugs. And yes, they
did come in
different widths depending on how many poles were required at that point in
the logic. My experience with them was in the early 60's and most of the
ones I encountered were silver rather than gold though. You should be able
to easily slide the wires out for inspection and just as easily slide them
back into place. With the silver ones we sometimes slid all the contact
wires out just enough to clear the contact posts and them ran a little flat
burnishing tool between all the posts to "clean" them. Some thought this
was counter-productive, and I can't really recall ever fixing a problem that
way. Unless a short occurs somewhere and actually destroys the wires and/or
contacts due to too much current, they seemed very reliable.
There was also a variant with two coils. When the main coil pulled the
relay in the armature became mechanically latched in that position. Then
some time later the smaller coil could be activated momentarily to unlatch
and allow the contacts to return to the normally closed position. Nice if
you needed it activated for long periods and didn't want to have to keep
current flowing through the main coil. Greener as well, before we even knew
what green was. :)
Later,
Charlie Carothers
--
My email address is csquared3 at tx dot rr dot com