Need urgent help with a weird situation – any advice?
in Computer Peripherals ·
If you don't have power, you're stuck relying on a battery... try picking up an old car alarm system and rigging it up. You could use microswitches on the doors and windows... or just set it off with an ultrasonic sensor...
Alternatively, just grab the loudest 12V piezo siren you can find at an AutoZone... wire it up with a latching relay (once it gets a signal, it stays on until the battery dies) and connect a microswitch to the doors or windows. Once it trips, that thing will scream until dawn... when you're closing the doors, just wedge a piece of cardboard or some tape to keep the switch from triggering... you could even mount some car headlights and wire them to the high beams... just make sure you mount everything—the relay, the siren, the battery—in a spot that's as high and out of reach as possible...
Alternatively, just grab the loudest 12V piezo siren you can find at an AutoZone... wire it up with a latching relay (once it gets a signal, it stays on until the battery dies) and connect a microswitch to the doors or windows. Once it trips, that thing will scream until dawn... when you're closing the doors, just wedge a piece of cardboard or some tape to keep the switch from triggering... you could even mount some car headlights and wire them to the high beams... just make sure you mount everything—the relay, the siren, the battery—in a spot that's as high and out of reach as possible...