# Thread: Building an Electromagnet

1. So I'm building an electromagnet using a nail and coiled wire. From doing research I've found that you can increase the power by adding more turns to the wire or inputting more current. My question is does "double wrapping" the wire make it more powerful? That is, once the nail is covered in coils will coiling the wire over the coils have any more effect? Thanks to anyone who can help.

Tyler

2.

3. Yes. If you have ever looked at an electromagnet, such as a speaker coil, you will notice that there are many layers of wire coils.

4. Hint: if you can, do open an (old and expendable) speaker, or transformer, or electric motor (e.g. from a broken toy), and have a look at the coil(s) inside. You will notice they are usually made of thin wire with only enamel for insulation, so lots and lots of turns of wire can fit into the available space.

5. More turns you can only reach the same power with less rotations per sec or minute for the driving machine.

Just a view turns can be compared with trying to drive fast with a bike that has only a very low gear. The power outcome is limited by ergonomic limitation. In the case of the coil it is limited by the "ergonomics" of the driving device.

But with high power input and a view turns the wires will melt or the wire must be much thicker so that,s another limitation.

6. Originally Posted by Tyler
So I'm building an electromagnet using a nail and coiled wire. From doing research I've found that you can increase the power by adding more turns to the wire or inputting more current. My question is does "double wrapping" the wire make it more powerful? That is, once the nail is covered in coils will coiling the wire over the coils have any more effect? Thanks to anyone who can help.

Tyler
Please ignore Ghrasp. As usual, he doesn't understand what he is talking about, or the nature of your question.

Increasing the number of turns in a coil will increase the magnetic flux density proportionally. In that sense it controls the "power" of the magnet that is manufactured.

What is true is that lectric power (volsts times amps) through a coild has little to do with the magnetic flux density. What controls the magnetic flux is the amperage (current) and the number of turns. In fact, sometimes in engineering applications the flux is measured in "amp-turns".

It makes little difference whether the coil is single wrapped, double wrapped, or more. There are some fringe effects but they can often be ignored. It is the total number of turns that counts the most.

The effect of the nail, which is made of a magnetic material, is just to concentrate the magnetic flux. The electromagnet would be formed without it, but would not be as efficient.

7. I understand power is here the magnetic strength not the energy outcome in that case dr rocket is right offcourse (for once) and you can ignore my post mostly.

8. I have no much knowledge about elctromagnet coil. So please share more information and uses of elctromagnet coil and who can i used in security system equipment.

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