On Sun, 06 Sep 2009 19:49:18 +0100, Phil Addison
wrote:

In the end I opted for simplicity and used the Maplin panel mount red
neon (BK52) which cost 99p, and took the return to earth; it works fine.

Here's the details...

1 Solder flex tail to neon, insulate with heat-shrink, and fit in 6.5mm
hole http://img35.imageshack.us/img35/760...nthewiresz.jpg

2 I soldered the fine wires to the switched load and earth of the mains
cable to guarantee a lasting connection
http://img142.imageshack.us/img142/7...redthefine.jpg

3 Reconnect mains cable to switch and the earth contact of back-box
http://img36.imageshack.us/img36/484...ecttoswitc.jpg

4 The re-fitted switch with its new red neon
http://img42.imageshack.us/img42/373...ittedswitc.jpg

5 Success!! http://img178.imageshack.us/img178/3...861success.jpg

Thanks for all the input and neat LED ideas, but its hard to beat the
neon for simplicity, cost, very low current draw, no visible flicker
(100Hz), all round visibility, and ready availability in panel mount.

.... and today we realised it also provides a clear 'engaged' indication.
OK, the LED schemes would do that as well, but the PIR's would not.

Phil