Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Security sensors



To get the ball rolling, I'll make a stab at it. (Since every-one else has had
a couple of days to answer.)

I've assumed the spiral is an inductor -- and disassemble it carefully and I
think you'll find it's two rectangles forming a cap., therefore, a parallel
resonant (L-C) circuit. The detector is like a metal detector -- radio xmitter
and receiver. The resonant circuit absorbs pwr., the the received sig. is
reduced, and voilla!

This is a "Cleyet" plausibility explanation.

bc


P.s. Tanks much for your riposte to the nasty can, do .. xxx teach.

Tony Wayne wrote:

I *faintly* remember a discussion once regarding how store security stickers
work. I'm looking at 2 types of sensors in my hand. One is a rectangle with
a spiraling wire on the back of a sticker. The other looks like 2 pieces of
metal in a plastic container. Could anyone explain to me how these work?
-tony
==========================================================
Tony Wayne Those that can,do.
wayne@pen.k12.va.us Those that understand, teach.