<<previous : next >>

From billbolto–(at)–cslink.net.au Sat Aug 23 23:31:25 CDT 1997
Article: 38764 of rec.audio.tubes
From: billbolto–(at)–cslink.net.au (Bill Bolton)
Newsgroups: alt.guitar.amps,rec.audio.tubes
Subject: Re: Standby switches (was Homemade Deluxe)
Date: Sun, 24 Aug 1997 04:14:37 GMT
Reply-To: billbolto–(at)–cslink.net.au (Bill Bolton)
Message-ID: <3403a288.548350--(at)--ews.onaustralia.com.au>
References: <33FB6DD1.7BC--(at)--orldnet.att.net.nospam> <33FC2F64.652--(at)--ivanet.com> <33FC941C.A--(at)--rols.com.nospam> <33FCC57D.1CE--(at)--PICED-HAM.Unisys.com>
X-Newsreader: Forte Agent 1.5/32.451
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Lines: 23
Path: geraldo.cc.utexas.edu!cs.utexas.edu!howland.erols.net!infeed1.internetmci.com!newsfeed.internetmci.com!!news.telstra.net!!
Xref: geraldo.cc.utexas.edu alt.guitar.amps:61285 rec.audio.tubes:38764

Andrew McWhirter wrote:

> I have often wondered about standby switch ratings. Seems whenever I’ve
> bothered to check, the switches were *not* rated for anything like the
> B+ present.

In standby switch applications (not necessarily in other DC switching
applications), you can generally count on the switch being able to
handle DC voltage to at least twice the rated AC voltage. For
instance, a switch rated to 250V AC should be capable of switching up
to 500V DC in a standby switch application (not necessarily in other
DC switching applications).

> I’m just wondering if the reason why is something like this: The switch
> (voltage) ratings are determined by the voltage that they can safely
> interrupt without arcing.

Many switches are simply rated for “AC” and show little or no
information as to the DC rating. Basically, the AC rating is for an
RMS AC voltage. The peak to peak AC voltage rating is actually much
higher and it is this peak to peak AC rating which is the governing
factor for DC standby switch applications (not necessarily in other DC
switching applications).



Bill Bolton
Sydney, Australia