Hi, I need to create an electromagnet that can lift a 1 KG Iron block that is kept at 30 cm away from the electromagnet. I have a DC power supply(RXN 305 D) that can provide a voltage of 0-30 Volt and current of 0-5 A. I need to limit the current used to maximum of 3 Ampere. Please help to design the core of the electromagnet, the number of turns and other factors to consider to achieve the goal above. The inspiration behind this is that- I had seen a youtube video recently where a person produce a strong magnet which could lift 50Lbs using the current from a simple 1.5 volt battery. I tried to wind the insulated copper wire in a normal iron nail we find in house ( 3 rounds one above the other cover complete needle) and passed up to 3 A current through it, but the magnet was not powerful like I found in the video. So I am trying to understand what could be done to make a powerful magnet like the one found in the video.