Why do transformers have to have thicker wires when the current is higher?

Have you ever wondered why the wires used inside the transformer thicken as the current increases? There is actually a profound principle behind this. The following will analyze in detail why the larger the transformer current, the thicker the wire:

Relationship between resistance and cross-sectional area:

The resistance of the wire is proportional to the length and inversely proportional to the cross-sectional area. This means that when the length of the wire is fixed, the larger its cross-sectional area, the smaller the resistance. In a transformer, if a thinner wire is used to carry a larger current, the wire will heat up too much due to the larger resistance, and the temperature will rise, which may affect the performance and safety of the transformer.

Relationship between current and heat generation:

According to Joule's law, the heat generated by the current passing through the conductor is proportional to the square of the current and proportional to the resistance of the conductor and the power-on time. Therefore, when the current in the transformer coil increases, in order to reduce the heat generation, the resistance of the wire needs to be reduced. By using thicker wires, the resistance can be effectively reduced, thereby reducing the heat generated by the current passing through and maintaining the stable operation of the transformer.

Relationship between current and voltage drop:

When transmitting current, the voltage drop on the wire is related to the current and resistance. The larger the current, the greater the voltage drop if the resistance of the wire remains unchanged. In order to ensure that electrical equipment can work normally at rated voltage, the voltage drop needs to be reduced. By using thicker wires, the resistance can be reduced, thereby reducing the voltage drop.

In general, the reason why the transformer current is larger and the wire is thicker is to reduce resistance, reduce heat and voltage drop to ensure the performance and safety of the transformer. When selecting wires, it is necessary to comprehensively consider factors such as current size, voltage level, efficiency, etc. to select the most appropriate wire specifications.