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trigger retail door alarm Answered

i know most people that think of retail exit door alarms want to avoid setting them off, but is there a way to purposely trigger them, especially from a distance? i am reasonably good with a soldering iron, ok using a ohm-meter and beginning on using oscilloscope. and i have lots of junk PC/PC parts and various other electronics around to strip for parts... (if that helps any). thank you for reading --rex

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rexifelis (author)2009-08-04

i appreciate your replies! im mostly wanting to hassle my friends... haha. but this has the potential of not being nice to them... now that i think about it. well, thanks for reading! --rex

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Kiteman (author)2009-07-28

If you get an un-cancelled RFID (the chip thing that sets off the door alarms), you can drop it in your sock, or somebody else's hood, and it will set off every door alarm it goes through. Kitewife ordered my headphones by post and we had to pick the parcel up from the sorting office, then every alarm we went though after that went off because there was an uncancelled RFID in the package.

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lemonie (author)Kiteman2009-07-28

Yes, that's the other system. But as RFIDs transmit data, I'm thinking that the ones that went off weren't configured in a particularly sophisticated way, unless they operate on the same frequency as the crude big-tags? L

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lemonie (author)2009-07-28

Yes, depending on the door-devices. A device like the receiver in this (without LEDs)
https://www.instructables.com/id/Wireless-Power-Transmission-Over-Short-Distances-U/
- will trigger some of them. I have hacked one out of a security-tag not removed in error, and it worked (in a wallet).
You'd need to do some research, but it's just a simple resonant circuit.
For remote usage, I think you're unlikely to succeed as these things do a local "hand shake". Maybe you could beam them a signal at the same frequency, but I'm not convinced it would work without knowing more about 'em.

L

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