Christian McArdle wrote:

Ah!, its not as simple as that, as consider where would the sensor be?,
somewhere near the light I'll wager, so when the light comes on how's it
going to tell when its dark again?.

When it turns on, it does so only for a period, such as 15 minutes. Then
it turns off again. If it is still dark, it will relight. This appears to
the user as a very brief flicker.

OK, thanks - that is probably why my device turns off at regular intervals.
I thought it was just a slightly bizarre scheme to scare off burglars.
So maybe I already have what I want!


--
Timothy Murphy
e-mail (80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland