On Mon, 28 May 2012 20:00:48 +0100, Jim K wrote:

low voltage PIR? what from where?

As used with intruder alarm systems. Many to choose from...

a normal 240v PIR and some sort of a relay?

Some 240v PIRs operate relays rather than being solid state. Wether
the relay contacts are "volt free" is another matter...

On both adjust the area "seen" by the PIR with bits of sticky tape.

--
Cheers
Dave.