Hi Engies, I've been bothered by this idea I've had for a while that seems too simple to work. Can somebody help me drown it in reason? I'll spare the redundancy of the whole idea, basically I need to know if there has ever been a spring made with attracting permanent or one permanent one electromagnet on either end that can lock the spring closed until the magnet is pulled away enough to release the springs energy or the electromagnet is turned off. The spring-magnet contraption would also have to be scale-able to the size and power of human spring shoes and as such would need to continue to function with the interaction of it's neighbor's fields as well. I feel like a permanent magnet would have to be too strong to hold down a human bearing spring while still being able to release it or maybe the magnetic drag on the spring would consume too much stored energy as it was being released, producing a jump too small to reset the springs. I have always been under-financed for formal education and as such have no internal repertoire of modern material properties. I considered this might be solvable by use of an electromagnet, however I know very little about their magnetic power or energy consumption. Ideally the electromagnet would not require much energy, very ideally it would self-generate from in-built kinetic generators and/or the electrical induction of the moving magnets, but like I said I don't know crap about them. TL;DR - Is there a possible tipping point of dominant forces between attracting magnets on either end of a spring? That's the basic idea, please kill it for me.