Suction cup electromagnet, frame electromagnet, tube electromagnet is how to work?

There is a distance can reach 1-2cm electromagnet, portable bad get, the magnet will be a little big, diameter of about 5cm, DC available battery pack to solve the general iron, just in the cover with the electromagnetic coil of the panel using multiple rows and according to a certain distance from the spacing of the pit casting into the aluminum bar, in order to get the aluminum bar spacing within the iron are with the N, S magnetic poles, prompting the suction force to enhance. Suction cup electromagnet is mainly used in cranes. As for the stroke, this is related to the crane itself. Suction cup electromagnet belongs to a kind of electromagnet, the so-called electromagnet, is energized to produce a magnetic field, which also produces N, S poles, no matter which level of the iron is attracted, so the suction cup electromagnet should be gravitational force on both sides! Also called lifting electromagnet, is controlled by the current electromagnet, can suck scrap steel and other metal materials, adsorption weight according to the size of the power to determine.