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How to: Time lock safe (unlocks after several months) Answered

Hi all, I have a client asking for a quote on creating a "time lock safe". It is a 6" x 13" x 15" portable safe (the ref pic they sent looks like a Pelican case). They would like to hand these out to their clients as a "brand-building experience " (or something like that lol). The box unlocks after a month or so and the client gets to keep whatever gift is inside. I have been looking into it and the longest delay I can find on commercial time locks is about 10 days. I imagine this is because the battery could die after that time? Anyway, just wanted to reach out to the community and see if anyone has attempted anything like this or has any suggestions about how to approach the build. I'm currently looking into builds like this: https://www.viralsciencecreativity.com/post/arduino-rfid-solenoid-lock But with the capability to stay activated for several months. Ok, thanks a bunch! Damian


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Onat Bulut
Onat Bulut

1 year ago

You can use DS3231 module and check the date using an arduino to open the lock at the given time. Opening date could be set in the code. Or you can go further by adding an lcd and some buttons to change the date (After thinking a bit, this one might not work if arduino powers off, deleting the unlock date setting. If you can not find a solution for that, use the first one.). Making it more user friendly. But the problem here is powering up the arduino. Considering it would be stationary, arduino could be powered up using a simple phone charger. Even the electricity cuts off, DS3231 will continue to work. Well, a backup power source might be handy too because if there is no power on the arduino and the lock at given date, you need to find another way to open up the safe Thats all I can suggest to you. It is not that much but I hope that helps.


1 year ago

You could simple add a clock and additional power supply.
There is programmable timers that go a month or even a full year.
Once the timer runs out use the output to sound a loud buzzer or have the time known to the customer.
Output stays on until the customer opens the safe and disconnects the circuit.
All you need to do is to wire the output into the magnet that unlocks the safe.
Of course that won't help for high security models with additional blocking mechanisms.