Transformers

Transformers

1. How They Work

   • (BASIC) A transformer needs an alternating current to create a changing magnetic field This changing magnetic field causes a changing voltage in a coil.
   • Primary coil attached to AC supply
     • Alternating current pases through the coil which is wrapped around an iron core
       • This changing current produces a magnetic field
         • This causes a changing voltage in the secondary coil
           • In turn causing an AC in the circuit attached to the secondary coil

2. These change the voltage of an AC supply if the transformer increases voltage its a "step up" if it decreases voltage its a "step down". They cannot work with a DC supply.

3. IMPORTANT INFORMATION

   • There is no electrical connection between primary and secondary coils.
     • Transformers only work if AC is provided to there primary coil if DC was supplied there would be no current in the secondary coil
       • As current in the primary coil increases or decreases steadily there is a constant voltage caused in the secondary coil
         • As voltage in the primary coil reaches its maximum the voltage in the secondary coil is at its weakest (zero)