In article ,
wrote:
We have two switches (on top of stairs, one bottom) for a light.
(It was set up in 1965, so I don't think there's fancy chipwork.) How
was this set up? I'm thinking of replacing one switch with an infrared
motion detector switch, but I have had some problems with these IR
detectors if the lightwork is too fancy (eg, one LED bulb would never
switch off in IR mode, but would manually switch on/off).



L1 L1
0===========0 0===========0============= Line
| \ / |
C 0================================O C
\ / \ /
0===========0 0===========0============= Switch return
L2 Optional L2
Intermediate


If you wanted to replace a two way switch with an IR operated one it would
need to have a Single Pole Double Throw relay etc. Ie, three switch
^ ^ ^ ^
terminals.

If you wanted to *add* it to an existing two way switched circuit it would
need a Double PDT relay wired as per the intermediate above, or the wiring
altered to take a discrete intermediate switch in one of the original
positions and the IR one as a two-way at the end of the altered circuit.

--
*Taxation WITH representation ain't much fun, either.

Dave Plowman London SW
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