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Kablooie

(19,032 posts) Fri Feb 21, 2025, 11:34 PM Feb 2025

I was thinking of a burglar alarm.

You put a key underneath a flowerpot next to the front door.
The key fits the front door but won't turn.
When you put the key in, it completes a circuit.
a deafening diesel air horn goes off right next to the front door,
Blinding floodlights turn on, aiming at the porch,
a red light starts spinning on the front fence next to the street,
and a very loud recording announces that house number 236 is being burglarized.

Assuming you always enter from another entrance, would this work?

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I was thinking of a burglar alarm. (Original Post) Kablooie Feb 2025 OP

If it weren't for family and friends many people would be worry free. taxi Feb 2025 #1

taxi

(2,672 posts)

1. If it weren't for family and friends many people would be worry free.

Reply to Kablooie (Original post)

Sat Feb 22, 2025, 12:15 AM

Feb 2025

It has to be asked, why would a burglar look for a key? And except for family and friends who else would know about a key?
To answer your question though, it would be fairly easy to hook up if the door wasn't used. A contact could be paired to either the knob or the latch and any movement would trip a relay. On the other hand, if you wanted to use the door and have a false key that would trip an alarm, then a key that is slightly longer would work. That key would either make or break a contact, but would require some disassembly and modifications.

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