How to power an electromagnet?
Is it better run an electromagnet of a bigger voltage(12V) with a smaller current(150mA) or with a smaller voltage 5V and a bigger current? Which will heat it up less? Does it even matter? The electromagnet will have to work for several hours so heat is my main problem. Also should I use thicker or thiner wire? I'm trying to build a electromagnet for a ferrofluid project.