Electronic components sources

From: David V. Corbin <dvcorbin_at_optonline.net>
Date: Mon Mar 22 19:18:03 2004

>>> However, a DPST (breaks both live and neutral) is safer IMHO

NO,NO,NO!!!!!!!!!!!!!!

This can potentially leave a circuit floating, wich can be much more
dangerous. Try to HI_POT test a device in this configuration, and you may
very well let the "magic-smoke" out. If you are switching on the raw power
side, the neutral should always remain connected. In fact this is code for
many (most/all) CE/UL approval stamps!

 

>>> -----Original Message-----
>>> From: cctalk-bounces_at_classiccmp.org
>>> [mailto:cctalk-bounces_at_classiccmp.org] On Behalf Of Tony Duell
>>> Sent: Monday, March 22, 2004 7:38 PM
>>> To: cctalk_at_classiccmp.org
>>> Subject: Re: Electronic components sources
>>>
>>> >
>>> > >>>>> "Mark" == Mark Tapley <mtapley_at_swri.edu> writes:
>>> >
>>> > Mark> Erik Klein wrote:
>>> > >> ...The other item I have is a DEC Rainbow with a
>>> busted power >>
>>> > switch. The switch a fairly typical wide rocker style in
>>> gray >>
>>> > plastic with a 1 and a 0 printed on it. Again, I can
>>> replace it >>
>>> > but I'd like a "correct" part if anyone has a source,
>>> part number >>
>>> > or spare.
>>> >
>>> > Mark> This is a reasonably common failure - mine has the
>>> same problem
>>> > Mark> (replaced by two SPST's side-by-side which I take pains to
>>> > Mark> throw simultaneously) and I've read of at least one other
>>>
>>> Has anybody tried taking the original switch apart and
>>> cleaning the contacts (if that's the failure mode)? I'vc
>>> repaired switches in other equipment that way.
>>>
>>> > Mark> (years ago, on this list). When/if they are found,
>>> please post
>>> > Mark> on the list - I'll definitely want one too.
>>> >
>>> > In the US, just one SPST should suffice, if it's in the live wire.
>>> > You need DPST switches in much of Europe because there you find
>>> > unpolarized outlets.
>>>
>>> However, a DPST (breaks both live and neutral) is safer
>>> IMHO. In the UK we have poilarised mains sockets, but I
>>> still always fit double-pole switches in stuff I've
>>> designed myself, just in case the socket is wired
>>> backwards, or whatever.
>>>
>>> I am also looking for a rocker switch, but a much smaller
>>> one. It's the type used in the HP98x0 calculators (and also
>>> the 9885 disk drive, 9877 tape drive, 9866 printer, and
>>> doubtless many other devices). It's DPDT and has 2 miunting
>>> lugs for 4-40 screws. I can provide dimensions if anyone
>>> thinks they know a supplier.
>>>
>>> -tony
Received on Mon Mar 22 2004 - 19:18:03 GMT

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