Indoor and outdoor padlock is best used as a school locker lock, gym lock, and gate lock, providing protection and security from theft Set your own four-digit combination ... to open on 0-0-0-0.

Here’s a really fascinating circuit that implements a combination lock using relays and logic gates. Even with the schematic and written explanation of how it works we’re still left somewhat ...

Imgur user [Criand] has been hard at work on his own project made entirely out of paper, a combination lock that can hold a secret message (reddit post). The motivation for the project was as a ...