# How do you build a transformer?

Please be specific when describing how to build it and please make sure the materials aren't too hard to get/buy.

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• Anonymous

You need a square magnet with a hole in the middle if you get me?

Then wrap wire around one side (the primary side) and connect it to an a.c source (it is very important that it is a.c (alternation current) ! ! !)

Then wrap wire around the other side (the secondary side) but have more or less coils.

Less coils around secondary side makes a step down transformer (reduces voltage) and more coils around secondary side makes a step up transformer (increases voltage).

Then connect the secondary wire to whatever you want, a voltmetre for example, to see if your calculations are correct.

You can calculate the change in voltage by using the formula:

Np / Vp = Ns / Vs

Np is number of coils on the primary side

Vp is the voltage on the primary side (the applied)

Ns is the number of coils on the secondary side

Vs is the voltage on the secondary side (the induced)

It is proportional so if the Np is 10 and Vp is 5 v, and Ns is 20 then

10 / 5 = 20 / Vs

Vs = 20 / 2

Vs = 10 v.

This picture is quite good http://upload.wikimedia.org/wikipedia/en/thumb/b/b...

Hope this helps.

• Anonymous