RE: Alarm Sensors - building into double glazed units

["Des Gibbons" <des@xxxxxxx>]

Hi Mick,


> lots of questions.....

:)

>
> what kind of windows are these (sash,side openers etc)?

14 top hung openers, 1 side hung opener.

>
> I thought the magnets would need to go on the moving part of the
> window not
> the static?

Indeed you would be correct ;) The switch goes in the static part.

>
> In my case the windows will have a very shallow channel (estimate
> 3-5mm) in
> both the frame and the window, however these are offset so the
> inner edge of
> the window channel is in line with the outer edge of the frame
channel. I
> dont have a problem with drilling the frame but dont really want
> to hack the
> windows about.

Thats exactly what I decided, frame, no problem, bit with glass, ooooeerrrr
missus.

If it is a rehau profile, I may have a section here I can send to you?
>
> I assume you are using the the flush mount circular contacts from
screwfix
> do you have any measurements (diameter and depth)?

Yup, thats the boys, measurements 20mm holesaw for cutting the frame, depth
of contacts, I'll have to measure tomorrow,can't find anything to measure
with! ( less than 20mm using the diamater as a rule :)

Any ideas on
> the distance
> these will actuate over?.

Hmmm, quick play with a multimeter, and they operate from quite a distance,
although the magnet may reduce in strength over time?

..in my case they will probably be mounted so the
> edges of the circles just touch when the windows are closed.

The edges don't have to overlap, so you will be fine, circles 10mm apart
would seem to be the limit.

>
> As the non wired part of these is just a magnet how about using
> some of that
> sticky backed magnetised strip stuff? I seem to recall it being used
for
> holding secondary glazing in place. Does that seem possible?

I have been looking at the magnets from the surface mount contacts as they
seem a better shape, but I am sure any magnet will do if you can get a high
enough strength field for your application.

I can send you a set of contacts if you aren't getting a big order from
screwfix. Are you in the south now, or am I getting you mixed up with
someone else? :)

Cheers, Des.