# Inductor question

#### Kari

Apr 2, 2014
10
So I was curious, what would be the result of winding an inductor around itself multiple times? As in at the end of the first coil, you wind the enameled wire back up around the coil and then down again several times? I don't really expect it to do anything out of the ordinary, just curious for a more seasoned hobbyist/professional's opinion.

#### BobK

Jan 5, 2010
7,682
Inductors are normally wound that way. The inductance is proportional to the square of the number of turns, so adding 1 layer to a 1 layer winding gives you about 4X the inductance.

Bob

#### Kari

Apr 2, 2014
10
Neat! So could you essentially create a supermagnet with a 9 volt battery?

#### BobK

Jan 5, 2010
7,682
Magnetic field is proportional to the number of windings and the current.

More windings = more resistance = less current, so it is not that simple.

Bob

#### Kari

Apr 2, 2014
10
So then the only way to make the magnet more powerful would be to increase voltage assuming resistance is constant?

Or are there other ways to increase current

#### BobK

Jan 5, 2010
7,682
More windings will increase the magnetic field if the same current is used, more current will increase the magnetic field if the same number of windings are used. The voltage needed to supply a given current depend on the resistance, which depends on the length (and inversely on the diameter) of the wire. More windings means more length, means more resistance. You can play with all of these things to increase the magnetic field.

Bob

#### Kari

Apr 2, 2014
10
was assuming there was already a multi layer inductor with a fixed number of windings, so constant resistance

#### duke37

Jan 9, 2011
5,364
You can play with the wire thicknes and number of turns but to get the same magnetic field, you will need the same power.
Get as much copper in there as is possible, if this is not good enough, use silver or a superconductor.

#### Kari

Apr 2, 2014
10
Perhaps someday i'll attempt something just for fun, like a big hollow inductor filled with metallic hydrogen.

Replies
16
Views
1K
Replies
4
Views
847
Replies
3
Views
1K
A
Replies
3
Views
4K
Michael Black
M
H
Replies
10
Views
1K
jasen
J