Oh, like I said, I'm sure there are plenty of electromechanical solutions and all of them will work for their owner preferences. But my preference (only for me) would be for the fusible plug or link and spring. I just meant that if you went electromechanical, I thought Andrew's design was one I liked.
But I'm a mechanical guy by preference, not an electronic guy, which is why I like this forum. I take joy in mechanical solutions to things, and the simpler, and the more they use common or recycled materials, the better (for me, only).
Not saying I don't use and like electronics (I own 2 cnc machines, built one). But my heart is in devices made of scrap metal and put together using hand tools, if I can manage it. If I had iron ore on my property, I'd probably be starting with that!