In article ,
Bob Minchin writes:
Paul G wrote:
My garage is attached to the house with a 3-way lighting circuit.
Sometimes the family leave these lights on and this is only discovered
when someone goes outside and notices the fact. One of the light
switches is inside the house (next to an internal door into the garage)
while the remainder are at either ends of the garage. I'd like to add an
indicator to the indoor switch to show when the lights are on. Because
it's a 3-way circuit, I think I need a new cable from the lights to this
switch. It's a single gang box but I am struggling to find a switch with
neon indicator that is fed separately. I'm sure this is all achievable
using a modular faceplate but frankly I'm hoping to avoid the expense
(of modular).

I am hoping someone can confirm I need to add a new cable for this, and
suggestions for a switch+(separate) neon indicator faceplate ?

Thanks Paul

Find a miniature mains transformer - secondary voltage irrelevant. Wind
a turn or so of insulated wire through the odd gaps in the core and use
this as a current transformer with a neon across the 240v winding.
You might have to play with the number of turns but the neon will strike
when the lighting circuit draws current.

If you're going to play with current transformers, bare in mind
that if you leave the windings open-circuit so no current can
flow, the voltage output will go very high. You may break down
the insulation, and/or give yourself a belt. Not sure how a
neon as the burden (current transformer load) would cope with
a filament lamp switch-on surge or a short circuit, but I
wouldn't be surprised if it blew up.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]