# Transformers

by sp00ky
Tags: transformers
 P: 22 I was just wondering how transformers actually operates. And I hear they need to use alternating current and I was just wondering why they need to do so.
P: 1,116
 Quote by sp00ky I was just wondering how transformers actually operates. And I hear they need to use alternating current and I was just wondering why they need to do so.
Transformers are large, ringed, pieces of metal that have two sets of coils around opposite sides. An AC current is used because this induces a magnetic field, that a DC does not. A different in the number of coils in the different sets means that the voltage changes from low to high or high to low (high and low not set values).

 PF Patron Sci Advisor Emeritus P: 10,400 To clarify Bob's post a little: Transformers require AC because passing AC through a coil creates a changing magnetic field around that coil. DC certainly does produce magnetic field, but it does not change with time. When an AC current is passed through one of the transformer's two coils (usually called the primary winding), its changing magnetic field also engulfs the other coil (usually called the secondary winding). The electrons in the secondary winding react to the changing magnetic field by continuously moving. (If you applied a DC current instead, the electrons in the secondary winding would only move for a split second, then settle down -- you'd get no continuous current.) In other words: a changing current in the primary winding induces a changing current in the secondary winding. Transformers thus allow the movement of electrical energy from one wire to another, without the wires ever having to touch -- the energy moves from one wire to the other through the changing magnetic field. As The Bob says, the ratio of the number of turns on one coil to the other also determines the ratio of the potential differences (voltages) through the two coils. - Warren
P: 22

## Transformers

okay...and is there only 2 types of transformers? A step up and a step down is basically the types of transformers there are right?
P: 1,116
 Quote by sp00ky okay...and is there only 2 types of transformers? A step up and a step down is basically the types of transformers there are right?
I can't see there being any others. You can step up the potential difference and step down the potential difference but what is the point in havong a transformer to keep the potential difference the same???

Chroot might say different and he will, therefore, be right but I think there can only be two.