This is a question about transformer and how it works I need some help please. Thanks?!!
1 Answer
A transformer is an a.c. (alternating current) device which converts electrical energy to magnetic energy and back again. In doing so the voltage can be altered.
Explanation:
A transformer is built from an iron core (details below) with two coils of (copper) wire wrapped around either side. An alternating current in the first coil (called the primary) induces an alternating magnetic field in the core (iron is very good at containing and transmitting magnetic fields.)
The alternating magnetic field then induces an alternating current in the secondary coil. The ratio of the voltages across the ends of the two wire coils is in proportion to the number of “turns” (the number of loops of wire) and the equation is simply:
If there are more coils on the secondary than the primary the voltage will rise (called a step up transformer) and if there are fewer the output voltage will be lower (termed a step down transformer.)
The formula above assumes perfect efficiency, but is normally good enough at this level. The loses that do occur are largely due to the alternating magnetic field setting up “eddy” currents within the conducting iron. These are at right angles to the magnetic field and so designers have sought to reduce them by “laminating” the core i.e. making it from strips of iron, insulated electrically from each other.
A diagram is traditionally helpful at this point:
