How Transformers work explained animation

Summary

This video explains the fundamental workings of transformers, focusing on their role in altering voltage levels. A transformer consists of a primary coil connected to an AC input and a secondary coil connected to a load circuit. By inducing a changing magnetic field in the core, the primary coil generates flux that the secondary coil converts into current. The video explains step-up and step-down transformers, where the ratio of coil turns determines whether the voltage increases or decreases. A formula is provided to demonstrate how the voltage is calculated, with an example showing a step-down transformer reducing 120V to 60V.

Takeaways

• 😀 Transformers consist of an iron core ring wrapped in coils, with two coils: the primary coil (connected to AC input) and the secondary coil (connected to an output circuit).
• 😀 The primary coil is connected to an AC input voltage, while the secondary coil is connected to a load resistance, without any direct physical electrical connection between the two coils.
• 😀 This setup allows transformers to alter electricity, either stepping up or stepping down the voltage.
• 😀 In a step-down transformer, the number of turns in the primary coil is greater than in the secondary coil.
• 😀 In a step-up transformer, the secondary coil has more turns than the primary coil.
• 😀 A constantly changing current from an alternating voltage source creates a changing magnetic field in the transformer core.
• 😀 The alternating current in the primary coil generates flux in the transformer core.
• 😀 The secondary coil converts the magnetic flux back into current flow, producing voltage at the load or resistance in the secondary circuit.
• 😀 A step-down transformer results in a lower secondary voltage compared to the primary voltage when the secondary coil has fewer turns than the primary coil.
• 😀 For a step-down transformer with 20 turns on the primary coil and 10 turns on the secondary coil, the voltage is halved from 120V to 60V using a simple ratio formula.
• 😀 The formula for calculating voltage change in a transformer states that the ratio of secondary voltage to primary voltage is equal to the ratio of the secondary coil turns to primary coil turns.

Q & A

What is the primary function of a transformer?

A transformer alters the voltage of alternating current (AC) electricity by using two coils of wire wrapped around an iron core, allowing it to step up or step down the voltage.

What are the two types of coils in a transformer?

The two types of coils are the primary coil, connected to the AC input voltage, and the secondary coil, connected to the output circuit with a load resistance.

What is the key feature of transformers that allows them to change voltage levels?

The key feature is the magnetic induction between the two coils, which are electrically insulated from each other but coupled through the magnetic field generated by the AC current in the primary coil.

How does a step-up transformer differ from a step-down transformer?

In a step-up transformer, the secondary coil has more turns than the primary coil, resulting in an increase in voltage. In a step-down transformer, the secondary coil has fewer turns than the primary coil, leading to a decrease in voltage.

What role does the iron core play in a transformer?

The iron core channels the changing magnetic field generated by the primary coil, facilitating the induction of current in the secondary coil.

How does an alternating current (AC) affect the transformer?

The alternating current creates a constantly changing magnetic field, which induces a varying flux in the transformer’s core, leading to the generation of a voltage in the secondary coil.

What happens to the voltage in a step-down transformer?

In a step-down transformer, the voltage in the secondary circuit will be less than the voltage in the primary circuit, based on the ratio of coil turns between the two coils.

How can you calculate the voltage decrease in a step-down transformer?

The voltage decrease can be calculated using the formula that relates the ratio of the secondary coil turns to the primary coil turns. For example, if there are 20 turns on the primary coil and 10 turns on the secondary coil, the voltage will decrease by a factor of 0.5.

What is the formula used to determine the relationship between primary and secondary voltages in a transformer?

The formula is: (Secondary Voltage / Primary Voltage) = (Secondary Coil Turns / Primary Coil Turns). This formula helps determine how the voltage changes based on the number of turns in each coil.

If a transformer has 20 turns on the primary coil and 10 turns on the secondary coil, what is the resulting voltage in the secondary circuit?

With 20 turns on the primary coil and 10 turns on the secondary coil, the voltage in the secondary circuit is 60 volts, calculated by multiplying the primary voltage (120V) by the turn ratio (10/20).