Re: Metal Plate

[Jim <alarminex@xxxxxxx>]

On Dec 15, 6:53=EF=BF=BDpm, "RockyTSquirrel" <gafa@/nospam/usa.com> wrote:
> ademco =EF=BF=BDmade one back in the 70's =EF=BF=BDthat had a complete sw=
itch/magnet =EF=BF=BDin the
> jam =EF=BF=BDand a metal plate on the moving part..
> (no magnet under the metal plate..)
> the units could be used =EF=BF=BDon a metal door without =EF=BF=BDthe met=
al plate..
> the unit =EF=BF=BDworked best if the switch/maget =EF=BF=BDwas placed in =
a wooden jam,
> cause if a metal jam =EF=BF=BDthe magnet would over time magnetize the ja=
m =EF=BF=BDand the
> switch would become questionable at best....
> we used hundreds of them up till around 1981.
> RTS


I'm pretty sure it was the Ademco # 56 magnetic contact. Cloudy white
plastic case with switch and magnet inside. Brassy colored plate came
with two little nails so  you could attach it to the edge of the door.
I've got a couple down in the alarm dungeon. They were supposed to
take the place of the #116 push button switches.

They were quite the innovation until they were out in the field for a
few years. Then the sliding magnets inside the case started to hang-up
after prolonged use or if they were used on a very busy door.  As you
said, they didn't do too well on metal doors either.