Re: "Magnet tamper" for surface mount contact?

["Bill" <bill190nospam@xxxxxxxxx>]

"Matt Ion"wrote in message
>
> What's the possibility of replacing the current contact and magnet with
> recesssed button-style units?
>

Very possible for most situations except one. But also I like the added
security of a 3 wire contact with tamper covers.

With the concealed contact, the wires are not accessible - so not to worry
about anyone messing with the wiring.

And there are other tricks which can be used on an exposed 2 wire contact -
like soldering the end of line resistor inside the contact, then anyone
attempting to short the two wires would trip the alarm. If you have several
doors and say a 1K EOL, I suppose you could use two 500 ohm resistors which
would cover two doors or use a panel with a lot of zones.

What I have seen mostly so far as an intruder defeating a door contact is
either to add an additional magnet, unscrew magnet from door and attach to
contact, or short the wires. And this is only with your more "educated"
intruders, which is quite rare (the educated part that is). So although it
is unlikely you would ever have a visit from such a pro, I do think it is
best to go beyond just using two wire surface mount contacts on doors which
open out.

Using a 3 wire contact (N/O *and* N/C) will make it quite difficult even for
the "educated" types to figure out what to do. But then there is still the
problem with the magnet. I suppose if the contact is very close to the
magnet (tight fitting door), you could remove the back cover from the
magnet, glue the magnet to the door, then screw the cover over that. Then
they unscrew the magnet, tape it to the contact above, but when they open
the door, the magnet glued to the door would open out with the door. So they
would just be taping the plastic case to the contact and not the magnet.