How does a transformer work?

Transformer Operation Principle

A transformer is an electrical device that operates on the principle of electromagnetic induction to transfer electrical energy from one circuit to another. It enables the adjustment of voltage levels within an alternating current (AC) system, either stepping up (increasing) or stepping down (decreasing) voltage while maintaining the same frequency.

Working Principle:

Basic Components
A transformer consists of two coils, known as windings—the "primary winding" connected to the AC power source, and the "secondary winding" connected to the load. These windings are wound around a core typically made of magnetic material (such as iron). The core serves to concentrate and guide the magnetic field generated by the current flowing through the primary winding.

Principle of Electromagnetic Induction
When AC current flows through the primary winding, it produces a continuously changing magnetic field. According to Faraday's Law of Electromagnetic Induction, this changing magnetic field induces a voltage (electromotive force, or EMF) in the secondary winding, even though the two windings are not electrically connected.

Voltage Transformation
The voltage induced in the secondary winding depends on the turns ratio—the ratio of the number of turns in the secondary winding to that in the primary winding. If the secondary has more turns than the primary, the voltage is stepped up; if it has fewer turns, the voltage is stepped down.

Current Transformation
Due to the conservation of power, there is an inverse relationship between voltage and current. When voltage is stepped up, current decreases, and when voltage is stepped down, current increases, thereby maintaining power balance.

Load Connection
The load (such as appliances or machinery) is connected to the secondary winding, which supplies 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 there is no direct electrical connection between the windings, enhancing safety and preventing unwanted current flow between circuits.

In summary, transformers operate on electromagnetic induction, where a changing magnetic field from 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 while maintaining power balance between the primary and secondary circuits. Transformers are essential components in power distribution and transmission systems, enabling efficient and safe electricity delivery.