Transformer

This section covers the operation of transformers, focusing on the relationship between the primary and secondary coils and the voltage transformation ratio.

The Transformer Equation

The fundamental equation governing transformers is:

$\frac{V_p}{V_s} = \frac{N_p}{N_s}$

Where:

• $V_p$ = Voltage in the primary coil
• $V_s$ = Voltage in the secondary coil
• $N_p$ = Number of turns in the primary coil
• $N_s$ = Number of turns in the secondary coil

This equation shows that the ratio of the voltages is directly proportional to the ratio of the number of turns in the primary and secondary coils.

Step-Up Transformers

A step-up transformer has more turns in the secondary coil ($N_s > N_p$). This results in the secondary voltage being higher than the primary voltage ($V_s > V_p$). Step-up transformers are used to increase voltage for long-distance transmission of electricity, reducing current and minimizing power loss due to resistance in the wires.

Step-Down Transformers

A step-down transformer has fewer turns in the secondary coil ($N_s < N_p$). This results in the secondary voltage being lower than the primary voltage ($V_s < V_p$). Step-down transformers are used to reduce voltage for safe use in homes and appliances.

Transformer Table

Type	Number of Turns (Secondary)	Voltage (Secondary)	Use
Step-Up	> Primary	> Primary	Long-distance electricity transmission
Step-Down	< Primary	< Primary	Household appliances, safety

Applications of Transformers

Transformers are crucial components in the electrical power system, enabling efficient transmission and distribution of electricity.

Long-distance power transmission: Step-up transformers increase the voltage of electricity before it is transmitted over long distances. This reduces the current, minimizing power loss due to resistance in the wires.

Household appliances: Step-down transformers reduce the high voltage from the power lines to a safe level for use in homes and appliances.