Relay computers

From: Peter C. Wallace <pcw_at_mesanet.com>
Date: Sun Sep 26 18:47:34 2004

On Sun, 26 Sep 2004, John Lawson wrote:

>
>
> On Sun, 26 Sep 2004, Gordon JC Pearce wrote:
>
> > Tony Duell wrote:
> >>> And slugged relays, with a big metal ring in the coil. These either delay
> >>> opening or closing, but I can't remember which way round it works.
> >>
> >>
> >> I believe (without running upstairs to look in 'Telephony' [1]) that you
> >> can arrange for either a slow make or a slow release
> >
> > Yes, but I can't remember which end you put the slug at for which action
> >
>

According to the Engineering Relay Handbook, slugs at the armature end delay
both pickup and dropout, while slugs at the heel end have little effect on
pickup, but delay dropout. The slugs function as a shorted turn which will
generate an EMF on changing magnetic flux and resulting current will oppose
(Lenz's law) the applied field until the resistance in the slug cause the
current to decay.


Peter Wallace
Received on Sun Sep 26 2004 - 18:47:34 BST