electro magnet

[balachandran.001]

holla people.

i trying to make a 9volt elecromagnet.can any one help.
a part of my project.

i details in how many coil and windings would help.
a chart would help.
cause i totally forgot the theory, now i have to do the research all again.
i never thought that this be asked this irretates


thanks in advance

 

[flat5]

Maxwell's equations - Wikipedia, the free encyclopedia

 

[Mike_2545]

If you plan on using a 9 volt battery, it will be one short lived electromagnet.

 

[crutschow]

You may be able to get a 9V battery to power the electromagnet for a reasonable period of time but it would require many turns of fine wire. The magnetic field of an electromagnet is determined by it's ampere-turns, so the more turns, the higher field for a given current.

For example 36AWG copper wire has a resistance of about 0.415Ω/ft. For 100mA of current, the needed wire coil resistance would be 9V/0.1 = 90Ω. This would require 90/0.415 = 216ft. of wire, giving 21.6 ampere-turns. Of course winding that much fine wire (36AWG is 5mil, about the size of a thick human hair) on a core without breaking it may require a coil winding machine.

 

[Roff]

You may be able to get a 9V battery to power the electromagnet for a reasonable period of time but it would require many turns of fine wire. The magnetic field of an electromagnet is determined by it's ampere-turns, so the more turns, the higher field for a given current.

For example 36AWG copper wire has a resistance of about 0.415Ω/ft. For 100mA of current, the needed wire coil resistance would be 9V/0.1 = 90Ω. This would require 90/0.415 = 216ft. of wire, giving 21.6 ampere-turns. Of course winding that much fine wire (36AWG is 5mil, about the size of a thick human hair) on a core without breaking it may require a coil winding machine.

Wouldn't that be 21.6 ampere-feet?
The number of turns would be dependent on the diameter of the coil.

 

[Sceadwian]

And the actual strength of the magnet will depend highly on the core.