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Extremely simple question

Recently some1 i know challenged me to get a circuit. This is for those safes with an electronic lock in them. Now when someone opens the lock, he/she always forgets to close it. Can someone suggest a simple circuit for an alarm which would beep when the door is open. Cant use any photo sensitive stuff coz unlike a fridge this doesnt have any light when it is open. You close it by just turning a knob, and a metal rod rolls into place. So some circuit in which maybe i can attach one lead to the metal rod and the other end to the metal rod lock..so that when it locks, the circuit gets completed and the alarm shuts down?? The reason I want to build one instead of buying is coz I did my electronics engg course in college ages back. Dont remember any darn thing as my field of work is entirely different. Thanks for ur help

Reply to
Keyser Soze
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A 'proximity switch' would do the job for open/closed detection. As used in burglar alarms etc.

Graham

Reply to
Eeyore

Nest time your friend neglects to close his safe door, sneak into his house while he's asleep and take everything out of it.

He will learn to lock his safe. ;-)

Good Luck! Rich

PS: Be sure and give his stuff back before he calls the gendarmes. ;-)

Reply to
Richard The Dreaded Libertaria

Well theres a small problem...that pers> >

Reply to
Keyser Soze

light when it

Unless he is in a habit of opening the safe in pitch dark the is bound to be enough light OUTSIDE the safe to affect a LDR.

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

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void _-void-_ in the obvious place

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Reply to
Boris Mohar

Sometimes the solution is less sophisticated. Glue a light spring in there so when the door is closed and the knob not turned, the door is immediately forced open. To keep it shut, the lock will need to be engaged.

Reply to
Brian

Who is she the rest of the time?

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Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

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