Im trying to design a maximum strength electromagnet. I have a soft iron core that is 1.3" (33mm) round by 1.9" (50mm) long and I'm using 12 volts of input and my wire gauge is 18awg. Unfortunately I don't have the proper program to achieve this task. I was wondering if there was anyone with the know how that could help. Thanks Warren.
Assuming this is a DC application, wind as many turns as you have room for.
The reason being, magnetization is the product of the number of turns and the current through them. If you double the number of turns, however, while keeping the wire gauge constant, you double the resistance and thereby get half the current from your fixed voltage source; the turns*current product comes out being the same. What's different, though, if you double the number of turns, is that the power that the coil will draw will be half.
So if you keep adding turns, the magnetization doesn't change, but the current drawn goes down, and consequently the power required to run the coil decrease, too.
(If you're intending to use AC though, even 50Hz or 60Hz, the above argument doesn't apply since it disregards inductance issues.)
The core dimensions in one think. The other is the dimensions of the available form of the coil, and the temperature limit of the coil (state above or includes ambient). With this three plus the wire diameter and available DC voltage and current, you can calculate the maximum AmperTurns you can get from this coil. With the core that you have, the maximum coil diameter will be 66mm and 50mm long. So in this case the maximum turns with awg 18 will be around 530 turns (or about 32 m of wire) and you can apply 2,5A to have 1300At or 0,022Tesla at the core tip. And your coil will keep at 35oC plus ambient. However if you make the winding on the same form but with awg 28, then you will get about 1400 At. A question is how do you know that you have a piece of a real "soft iron"? Do you have a picture or a cut of this?