'Driveway Patrol'
is a wireless beeper with remote sensor, (range maybe even 600'.)
Dirt cheap on Amazon -- $15ish at time I + neighbor bought a couple sets.
I needed to monitor In/Out to garage re. Outdoor Cat, Petra and especially.. ^%#@%$@^$! raccoons!
enroute to check if any food is left over.
(And yess, after being busted/rousted maybe 10X-in-a-row ... raccoons Can Learn to fuck off!)
It helps to toss a few small rocks at them as they waddle away, to emphasize that it is Not a game for their amusement.
These are nasty creatures, known/seen to mutilate chickens wholesale, even through fence wire -- for no reason associated with food / just Repo-grade blood lust.
Reliable, decent battery life: 3 C-cells in base monitor + a 9V in sensor/xmitter ... lasted many months. (9V must have been drawing only μamps in wait-mode.)
False alarms arise only if foliage is in scan field + wind-motion or.. early morning sun direct (you make a toilet paper tube collimator for more directionality.)
All-in-all, I thought these a bargain which did exactly as claimed. A lot of well-designed techno for a pittance.
As to bathtub matter: 2 loudnesses of monitor alarm means that, with receiver in tub with sensor -- cat would exit in-haste, I wot.
Lots of other applications come to mind, not least of which -- as it is IR and invisible with easy camouflage of sensor
-- prowler confirmation, cheaper than CCTV if not quite as amusing or evidence-creating.
Bon appetit
Ed: 3 C-cells, not 4.
Edited by
Ashton
May 7, 2011, 04:00:50 PM EDT