Transformers?

Would anyone be able to explain step up and step down transformers to me? Only need the basics as its for GCSE physics. Thankyou.|||There's more than meets the eye. Optimus prime transforms into this truck and megatron transforms into a gun.





Ohhh.... transformers?





Okay, you run AC current through a coil. The sinusoidal current induces a sinusoidal B-field in the middle of the coil. So you have changing magnetic flux in the coil. Now put another coil in the same place as the first (but not connected). The changing magnetic flux induces an EMF in this second coil. If you put in lots and lots of turns in the secondary, you will have a large EMF (and smaller current). If you put in fewer turns (and more in the primary), you will have less EMF and more current in the secondary. So depending on how you build it, you can use this device to step up or step down the voltage between the primary and secondary.|||Electrons flowing in a coil generate an elctromagnetic field. This field can cause the electrons in another coil to strart flowing. It can step down or step up, depending on the number of wraps of wire in each coil.|||As others have pointed out, voltage (electric pressure) applied to a coil of wire causes a current flow which creates a magnetic field (the same thing that magnetics creat to attract iron). In a transformer this field is channeled thru a iron bar about which is coiled another wrap of wire and the field of magnetism will create a voltage in the second coil.





If the second coil has fewer windings than the first, then the voltage in the second coil will be less. This would be a "step-down" transformer.


If the second coil has more windings, the the voltage in the second would be more. This would be a "step-up" transformer.





Transmitting power over long distances (the power plant to your home) is more economical at very high voltages (pressures) because less current flows %26amp; there is less loss thru heating the transmission wiring. But your home appliances use low voltages. So the pole outside will have a "step-down" transformer to give you what you need.