A transformer is an electrical device that works on the principles of electromagnetic induction to transfer electrical energy from one circuit to another. It allows for the change of voltage levels in an alternating current (AC) electrical system, either stepping up (increasing) or stepping down (decreasing) the voltage while maintaining the frequency of the electrical energy.
Here's how a transformer works:
Basic Components:
A transformer consists of two coils or wire windings . The coil connected to the AC power source is called the "primary winding," while the coil connected to the load is called the "secondary winding."
These coils are wound around a core, typically made of a magnetic material, such as iron. The core helps concentrate and guide the magnetic field produced by the current flowing through the primary winding.
Principle of Electromagnetic Induction:
When an alternating current (AC) flows through the primary winding, it creates a changing magnetic field around the primary coil.
According to Faraday's law of electromagnetic induction, this changing magnetic field induces a voltage (electromotive force or EMF) in the secondary winding, even if they are not electrically connected.
Voltage Transformation:
The voltage induced in the secondary winding depends on the turns ratio between the primary and secondary windings. The turns ratio is the number of turns of wire in the secondary winding compared to the primary winding.
If the secondary winding has more turns than the primary, the voltage is stepped up (increased). If the secondary winding has fewer turns, the voltage is stepped down (decreased).
Current Transformation:
Since electrical power must be conserved, there is an inverse relationship between voltage and current. When voltage is stepped up, the current is reduced, and when voltage is stepped down, the current is increased to maintain power balance.
Load Connection:
The load, such as electrical appliances or machinery, is connected to the secondary winding of the transformer. The secondary winding provides the transformed voltage to power the load.
Isolation and Galvanic Separation:
Transformers provide electrical isolation and galvanic separation between the primary and secondary circuits. This means that there is no direct electrical connection between the primary and secondary windings, enhancing safety and preventing unwanted current flow between them.
In summary, a transformer operates on the principle of electromagnetic induction, where a changing magnetic field created by the primary winding induces a voltage in the secondary winding. By varying the number of turns in the windings, transformers can step up or step down voltage levels while maintaining the power balance between the primary and secondary circuits. Transformers are essential devices in power distribution and transmission systems, enabling efficient and safe transfer of electrical energy.