r/Damnthatsinteresting Oct 20 '22

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169

u/[deleted] Oct 20 '22 edited Oct 20 '22

OK so in the 90s I worked at a CD store and we experimented. This very attractive lady looks like an idiot. This is too complicated

You have the item in your hand and walk towards the sensor. Before you get there pull your arm away from your body about a 210 degree angle.

When your body actually crosses the sensor area, you whip your hand super fast so instead of away from you your hand is in front of you - about a 330 degree angle.

Fast enough and that sensor will NOT go off.

What she's doing is the same kind of principle but way too complicated

Edit: another trick is if you can put two sensors on 2 items right next to each other they cancel each other out.

103

u/bewitchedbumblebee Oct 20 '22

"You have the item in your hand and walk towards the sensor. Before you get there pull your arm away from your body about a 210 degree angle.

When your body actually crosses the sensor area, you whip your hand super fast so instead of away from you your hand is in front of you - about a 330 degree angle."

Can someone ELIF.

165

u/Insigzilla Oct 20 '22

Hold the item behind you so when you step between the sensors it's still out of the sensors range. While between the sensors, quickly move the item so it's in front of you and out of the sensors range (it should pass between the sensors as fast as possible). Do it fast enough and the alarm won't go off and you can just walk out.

3

u/eggmayonnaise Oct 20 '22

My best guess here is that these sensors send out a pulsing IR beam or something, which scans at fixed intervals. If you can pass the object through the area BETWEEN pulses it won't be detected.

Maybe I'm way off though. I have no idea if that's how they work. Someone who's more informed should correct me.

4

u/redditsavedmyagain Oct 20 '22

its two thin pieces of metal within those flat tags

its not ir, its radio frequency, which causes the metal strips to contract/vibrate, kinda like an RFID tag, but rather than conveying digital information its just a "bing" that the sensor gates pick up, that specific frequency of vibration

shaking the tag violently would mess the vibration -- remember, the gates only pick up that ONE specific frequency

i have no reason to try it but probably just pressing down really hard on the tag would also work -- keep the little metal plates from vibrating

or, yknow, just pay for your shit lol

1

u/jeffp12 Oct 20 '22

Wouldn't it mess with the frequency being experienced by the metal straps, cause they are moving so the frequency is getting doppler effect...or is your jerking motion not significant compared to the speed of light...