9 Nov
2006
9 Nov
'06
2:47 p.m.
der Mouse <mouse at Rodents.Montreal.QC.CA> said:
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).
House 4-way switches DO exist. They have 4 terminals (thus the [USA/NEMA]
"4-way" designation). They preform the
"normal"/"cris-cross" switching
function. A quicky web search <"4-way" switches> got lots of answers, and
you
can buy these (new, sorry not 10 year old) devices. The first return from a
yahoo search has a nifty animation on how this all works. The technology has
been in use for quite some time (the house I grew up in used a 4-way switch in
the 50's). The problem is that not many places stock the things (I looked on
Home Depot's site to no avail). Basically the switch train is a bunch of
exclusive-or's so that any switch can make the "sum" 1 (on), or 0 (off).
I had to get a computer reference in there somewhere!
If you do decide to do some wiring, be careful. There are lots of references
on the web on the "how-to" aspects.
Ob antique stuff: Yes, the house also (the part built in 1946) had knob & tube
wiring. The other part (built in 1952) where the 4-way switch was had
something resembling romex.
--
Tom Watson
tsw at johana.com
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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?