On Mon, 16 Jun 2008 12:08:42 -0500, 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.


Large dog.