I have a project where I would like to use an electromagnet to lift an item for a longer period of time. I was looking at a magnet like this one:
http://www.ebay.com/itm/110880874455?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649
Problem is that seller states that it should not be used for more than 5-10 minutes at a time (without severe reduced lifespan). I would like a magnet that could stay on for an hour at a time at least and lift/hold maybe 20kg. Is this possible?
I was thinking that one might be able to do this by getting a significantly larger magnet than required and powering this on a lower voltage than specified to avoid it burning out (less current going through the coil), but this is just a guess on my part.
Best Answer
Old reply, but thought it may help others Tricks for getting solonoid continuous duty (stay on) and redusing energy! (use resister(still now resister gets warm(think cooling). also create duty cycle see here: http://www.electronics-tutorials.ws/io/io_6.html