Electromagnet contact distance

[MrOzil]

Does anyone know how to make the electromagnet attract object from further distance ?

im trying to make the electromagnet attract the object 3cm from the surface. At the moment my electromagnet can only attract at distance of 0.5 cm from the surface.

Please give me ideas thanks. really appriciate it

 

[ronv]

It is mostly about amp turns and core saturation. So a higher voltage (thus higher current) would make it more powerful, but at some point temperature will be a problem.

 

[dougy83]

The core shape is also important, e.g. a horseshoe-shaped core will have more attractive force than a bar-shaped electromagnet.

 

[unclejed613]

core shape and ampere-turns are the important variables. many turns of heavy gauge wire running amperes of current, and a horseshoe or cup core (or an E-core from a transformer). if you look at the electromagnets used for lifting cars in a scrap yard, they use many turns of big (1500MCM) wire, and feed it lots of current about 200A), and on a shallow cup core (think of a frisbee with a post in the middle).