I am working on a project, in which I have a small box, in which I need it to be locked from the inside. It will have a panel on the front to enter in a code to open it. It needs to be very small, with a small battery.
I was thinking of using a solenoid to have the pin extend, and go through a circular latch to keep it shut. I have seen that even the small solenoids draw a lot of current and am unsure if there is a better way.
I have also seen just linear actuators, driven by a servo/motor, but they seem quite weak for this.
It doesn't need to be really secure, it just needs to keep it shut and prevent easy opening of it. I also would like it to be powered by a single LiPo cell, as that makes it easier for the charging circuitry.