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Subject: Re: cards with fingers

From: "Steve" <alienrelics@...>
Date: 2006-06-16

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:
>
> On Fri, 16 Jun 2006 00:56:34 +0200, Steve <alienrelics@...> wrote:
>
> > Yes, to both. However, I'm thinking there are reasons it isn't used on
> > edge connectors, which all seem to be either true tin plated, or gold
> > plated. While silver oxide is a conductor, I seem to recall that it is
> > not a very good one.
> > Steve Greenfield
>
>
> I think i may have seen some, in TVs. Certainly rotary switches that
have
> the same sliding/wiping action.

Doh! I should have remembered that.

The difference: those are self-cleaning because they get turned
constantly. There is grease/oil on them that tends to keep oxygen away
from the silver, plus rotating it scrapes off the relatively soft
silver oxide.

I've seen TVs get bad reception when left on one channel for a long
time, the fix is to change channels a few times.

Steve Greenfield