Mutual induction is the phenomenon where a changing current in one coil induces a voltage in a neighboring coil due to the shared magnetic field, demonstrating the transfer of electromagnetic influence between the coils.
\[ E_s \rightarrow \infty \frac{\Delta I_p}{\Delta t} \]
\begin{equation} E_s = – M \frac{\Delta I_p}{\Delta t} \end{equation}
Where M is a constant, called Mutual Inductance of the two coils.
Hence:
\[ M_s = \frac{E_s}{\frac{\Delta I_p}{\Delta t}} \]
A transformer is an electrical device that uses mutual induction to transfer electrical energy between two coils, typically the primary and secondary coils, by changing the voltage and current levels while maintaining the frequency.
The basic transformer formula relates the voltages and turns of the primary (Vprimary) and secondary (Vsecondary) coils as:
\[ \frac{{\text{V}_{\text{secondary}}}}{{\text{V}_{\text{primary}}}} = \frac{{\text{N}_{\text{secondary}}}}{{\text{N}_{\text{primary}}}} \]
where (Nsecondary) and (Nprimary) are the number of turns in the secondary and primary coils, respectively.
Transformers play vital roles in daily life, including:
They step up voltage for efficient long-distance transmission and step down voltage for safe local distribution in electrical grids.
Transformers in chargers for smartphones, laptops, and other devices convert the high-voltage AC power from outlets to lower-voltage DC suitable for charging.
Many household appliances, like refrigerators and air conditioners, use transformers to adapt voltages for their internal components.
Fluorescent and LED lights often have transformers to adjust voltage and current to levels suitable for lighting elements.
Amplifiers, audio systems, and musical instruments use transformers to match impedance and isolate circuits.
Transformers provide the high currents needed for welding by stepping down the grid’s high voltage.
Medical devices require different voltage levels, and transformers help ensure safe and precise electrical supply.
Transformers provide different voltage levels for trains, supporting their various functions and needs.