Randy wrote:

My shop has no windows so on nice days I like to keep the overhead
door open. Well some kid watched me welding for awhile then decided
it was safe - snuck in and stole my laptop computer that was connected
to my CNC mill.

Got him on video, filed a police report.

I need some kind of photocell and beam across the doorway to alert me
if anyone walks in. Can garage door safety beams be used? I have a
couple of friends that can wire up or build me a circuit to make them
work, I just don't know how the work, is there a NO or NC output on
those? I was told you cannot just jumper them out, so I'm thinking
it's more like a signal output rather than a switch closure output.

Thank You,
Randy

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I have the exact same problem, being in downtown Nashville a few blocks from
the homeless mission. I call my alarm "bum alert". I have an infrared
beam with a NO output sending power to a VERY audible chime. The beams are
placed just inside the overhead door at 24" high. I have a bypass switch
so I can kill it while backing in a trailer or other such blockage. The
trick is placing the chime far enough away from the beams that the average
person can't tell where the trigger is.

Before I had mine installed, I would turn around and have a bum three feet
behind me wanting a handout. More than a few times. I have had people try
to jump it, but most of the time they trip it.

Here are the beams I use:
http://tinyurl.com/5rnnty

I had a set left over from a gate operator job. A security buddy flowed me
the chime and a power supply & I was set. Less hassle than a pooch.

Good luck.

John L. Weatherly

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