Welcome to the PF. The traditional way to do that function is with a solenoid, which attracts a ferrous bolt into a soltnoid with the current flows through the solenoid (Quiz Question -- why does it attract the bolt?).I am making a locking mechanism with a very powerful magnet. The electromagnet in the diagram is held in place. Basically when the electromagnet turns on it will push the permanent magnet out. Here is a picture of what I want to do.
Just as a magnetic field in one direction is used to magnetize the magnet, a magnetic field in the opposite direction will serve to demagnetize it (or even magnetize it in the opposite direction, if the field is stong enough).Another question. Why will the coil field demagnetize the permanent magnet?
Those are internal doors, obviously. Our elevators are also designed to drop to Floor 1 and open their doors in emergencies. We test those things pretty regularly.Ie, many commercial buildings use purely magnetic locks (a magnet literally holds the door closed). They release when power is lost, which can be advantageous for an emergency.
Yes. And ironically, the opposite also exists (didn't think of it when I wrote that last post). Fire doors can be propped open normally if they are held open by a magnet, closing (but not locking) in the event of a fire to stop it from spreading.Those are internal doors, obviously. Our elevators are also designed to drop to Floor 1 and open their doors in emergencies. We test those things pretty regularly.