On 25 Jun, 15:20, "N Cook" wrote:
Seán O'Leathlóbhair wrote in message

ups.com...
I am not sure if this is an appropriate group for this question. If
not, please suggest a better one.

I have a light in the house which I have wanted to switch to a low
energy bulb for a long time. The hold up was that I needed a very
small bulb. At last, I have found a small enough bulb but something
odd occurred as soon as I put it in.

When it is switched on, it works as expected.

When it is switched off, it blinks every few seconds. So, I guess
that there must be a problem with the switch If it is passing nothing
then it would seem impossible for the bulb to do anything. I did not
notice any problem with the previous incandescent bulb but I guess
that if the switch is leaking a tiny amount, the filament would glow
too little to be seen.

I have a few questions:

What is going on? Is a tiny current leaking, building up a charge in
a capacitor somewhere until a sufficient voltage builds up to spark in
the bulb and discharge the capacitor, and then the cycle repeats.

Is it safe?

Will it wear out the bulb very fast?

Is it likely to be enough to replace the switch? (Actually three
switches can turn this bulb on and off).

Might I have to replace the wiring? (Much harder than just replacing
the switches)

--
Seán Ó Leathlóbhair

It may not be a switch problem but more seriously an animal , usually
squirrel or mouse or rat has chewed the insulation along the wires going to
the switch, now with charred insulation, so passing a bit of current - so
get the wiring leakage/visually checked. Especially if you've had any
unexplained fuses blowing or history of animal noises in loft or floor
spaces.


Thanks for the advice.

We had some fuse problems many years ago but not on the lighting
circuits. The problem was traced (by a proper electrician) to the
ancient (bakelite) fuse box. It was replaced with a modern fuse box.
The wiring was tested (but not completely inspected) at the time.
Since then, we have not had any fuse problems. That was about 10
years ago.

I am not aware of any animal problems in the loft but, of course, that
does not mean that there have not been any. Access to the loft is
difficult since it is very small but not quite impossible. I will
squeeze myself in and have a look.

--
Seán Ó Leathlóbhair