On Mon, 18 Feb 2008 18:46:22 +0000, James Salisbury
wrote:

Sounds like a suitable project for a PIC, give me more details and I
will see about programming a 12F or similar.

Hi James, Thanks you for the sugestion. I've decided that what would
work best for my application would be a clap switch (one that is
activated by the sound of a hand-clap or two hand-claps). I would like
the light to stay of for a while after the hand-clap (I'd like the
duration to be able to adjustjustable, via a potentiometer - from 10
minutes to 10 hours would be ideal). The switch would ideally be
powerd by 12v dc: same as the light. The power source is a 12v gel
cell battery. There are clap-switch kits around (for about £10) but
not with the timer feature, as far as I know.

There is a timer circuit on this page (designed for use with a PIR
switch) (the last circuit on the page):
http://www.reuk.co.uk/PIR-Sensor-Circuits.htm

Perhpas that circuit could be used with a clap switch circuit? The
ideal switch could also be reset to 'off' with another hand-clap (or
double-handclap).

I'm afraid my understanding of circuits is rather feeble. I have built
circuits from kits, but understanding how they work, when they involve
transistors or ICs is beyond me at present. I'm working on it though!

He's a c/d for a simple clap switch:
http://tinyurl.com/25zhrm
And another:
http://tinyurl.com/2fd4st
And another, more complicated one:
http://tinyurl.com/23ztbs
And an even more elaborate one:
http://tinyurl.com/2ebgfy

Regards,

JD