New monitors on old machines

[Patrick Finnegan]

On Tuesday 07 November 2006 14:52, der Mouse wrote:
> >> 7) Three way switch at the other enough of the hall.
> >
> > It's already on a three-way switch with the bottom of the stairs...
> > do they make 4-way switches?
>
> Yes.  You need two SPDTs (which you already have) plus as many DPDTs
> as necessary to fill out the desired quota of switches (which means
> just one of them, in your case).  I've seen it done (at least for
> three switches).
>
> You need to cross-wire the DPDT, but that's no biggie (drop me a line
> if you don't know the wiring and I'll outline it for you); I think
> there even exist DPDTs pre-cross-wired to be total no-brainers for
> this application.

Yes, in fact they're called a "4-way" switch at your local hardware or 
electrical supply store (because they have 4 terminals).

There's some explanation complete with ASCII art diagrams here:
http://www.homeautomationindex.com/4waywire.html

Pat
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