"Joseph Gwinn" wrote in message
...
In article ,
Nick Hull wrote:


http://www.palmbeachpost.com/accent/...2005/08/11/a1e
_ron_col_0811.html

Inventor has a sprinkler interconnected to burglar sensors so burglar
gets wet. Apparently burglars do not like to get soaked by a sprinkler
so they go somewhere else. Sounds interesting, no worries about false
alarms.

I saw in a catalog somewhere an IR-triggered waterjet intended to keep
deer and other animals away from the shrubbery. Same idea, but
outdoors, with less precision. Seemed like something one could easily
cobble together from an IR motion detector (usually used to turn lights
on) and an electrically controlled valve controlling an ordinary lawn
sprinkler.

Works fine at night when it is cool. Passive IR sensors (your typical
"motion sensor" are blind during the day when it is warm and the
bodies are warm. And yes, many burglaries occur during the middle
of the day. You could run some IR beams around via sender/receivers
so they break the beam when they go through it -- that works any
time, but is more difficult to build (like the door entry things in many
stores).

mikey