HI all, my first post here so please be gentle with me. So that you can pitch any advice at the right level, I'm a retired electrical engineer.
I have an old alarm that we inherited when we moved into this house 20 years ago - the box is marked ADE OPTIMA COMPACT - see attached pics (I've managed to find instruction and installer manuals for it online).
Quite a while ago a couple of the PIR sensors started going off for no apparent reason so for years I've just been omitting the zones when I set it, but I've finally decided to try replacing them. Started by googling to see if I could find something that looked like the ones I have, but they seem a little tricky to find (see attached pics of the old ones). The voltage supply to the PIR is 13.5V or so, which I'm assuming is approx 12V, which most of the available PIRs seem to be rated at.
I'm really looking for guidance as to what PIRs would work with this system. So far I've found these, which look as if they might be OK, but technical info is very sketchy. - https://www.shg-uk.co.uk/Pyronix--PIR-DUALTECH-15m-FPKX15ED?PPCT=1663776703&gclid=CjwKCAiA9NGfBhBvEiwAq5vSy8eVwt9-sZeluJ9W2qdE6WgxESZz5G8u9W9-Jr2tQlXxuF7x4hIouBoC-awQAvD_BwE
I'd also like to install one of these in the garage to replace the old reed switch on the door (I've just had a new door fitted, forcing me to get round to this job). The only drawback might be getting the 12v into there as currently the appropriate cores of the alarm cable going in there don't seem to be connected in the alarm box.
Thanks in advance for any help.