Door Contact With Wide Operating Distance?

[Guest damian_taylor]

Hi.

I have a surface mounted reed switch on my uPVC door but because the operating distance of the switch is 14mm max I have to have the magnet half of the switch sat on top of the door (the switch half is buried nicely in a groove in the frame).

I would like to bury the magnet half in a similar groove on the door but would need a switch with a wide operating distance.

Does anyone know if there is such a switch available and where I can get one from?

Thanks a lot,

Damian

[antinode]

It sounds like you require a heavy duty surface contact, though they are pretty cumbersome (they are about the same size as a 6 way junction box) so it might not fit on your door! The ones I've used are made by a company called Maximal, and to be honest, I've never seen them for sale except in proper intruder alarm wholesalers so you may have a problem obtaining a pair. If you do manage to get one, you could probably get away with just replacing the magent, which is twice the size of the one in a regular surface contact. They have an operating gap of 25mm.

Edit: Maplin have some here but I can't vouch for the quality.

[norman]

I have some small neodymium (sp) magnet's I use in cases like this. about 5mm dia. x 8mm in length and slip nicely into a 4.5mm hole. I got them from e-bay about 50p each and have got me out of some holes with existing internal doors where the door has become warped and the old magnet wont pull.