What is a Transformer? Transformers Explained - Working Principle (Transformer Tutorial)

Summary

This lesson explains the working principle of transformers, essential electrical machines that increase or decrease voltage without changing frequency. Used in various applications, from power plants to household devices, transformers operate through electromagnetic induction. The video details the process of stepping up and down voltage for efficient long-distance transmission, minimizing energy loss. It covers Ampere's Law, the structure of transformers, and the importance of winding ratios. Additionally, the use of oil for cooling in large transformers is discussed, highlighting their efficiency and operational safety.

Takeaways

• 😀 Transformers are essential electrical devices used to increase or decrease voltage and current levels without changing frequency.
• 😀 They operate on the principle of electromagnetic induction, transferring energy between circuits efficiently.
• 😀 Electricity generated at power plants is first stepped up to high voltage for long-distance transmission to reduce heat losses.
• 😀 The power formula P=VxI indicates that increasing voltage reduces current, minimizing energy losses in transmission.
• 😀 Transformers consist of primary and secondary windings, with their voltage transformation based on the number of turns in each winding.
• 😀 Only alternating current (AC) can be transformed by transformers due to the changing magnetic field, while direct current (DC) cannot.
• 😀 Step-up transformers increase voltage from primary to secondary, while step-down transformers decrease it.
• 😀 The efficiency of transformers can exceed 90% by using laminated iron cores to reduce energy losses.
• 😀 Large transformers use oil for cooling and insulation, helping to manage heat during voltage transformation.
• 😀 Understanding the structure and operation of transformers is crucial for their effective application in power distribution.

Q & A

What is the primary function of a transformer?

The primary function of a transformer is to reduce or increase the voltage and current levels of alternating current (AC) without changing its frequency.

How do transformers improve energy efficiency during transmission?

Transformers increase the voltage for long-distance transmission to reduce power loss due to heat in the wires, as higher voltage allows for lower current.

What is the principle behind the operation of transformers?

Transformers operate based on the principle of electromagnetic induction, where a changing magnetic field induces voltage in the secondary coil from the primary coil.

What happens to the voltage when AC is transformed?

When AC is transformed, the voltage can either be stepped up or stepped down depending on the number of windings in the primary and secondary coils.

Why can't direct current (DC) be transformed like AC?

DC cannot be transformed because it produces a constant magnetic field, which does not change and therefore cannot induce voltage in the secondary windings.

What does the conversion ratio in a transformer represent?

The conversion ratio, expressed as 'n', represents the ratio of the number of turns in the primary and secondary windings, which directly correlates to the voltage change.

How is the iron core of a transformer designed to improve efficiency?

The iron core is made of thin plates stacked together to reduce energy losses due to eddy currents, enhancing the transformer's efficiency.

What role does oil play in large transformers used in power plants?

Oil in large transformers helps to dissipate heat generated during operation and provides insulation to the internal components.

What is the difference between a step-up and a step-down transformer?

A step-up transformer has more turns in the secondary coil than in the primary coil, increasing voltage, while a step-down transformer has more turns in the primary coil, decreasing voltage.

How does the number of windings affect the voltage in a transformer?

The voltage in a transformer is directly proportional to the number of windings: more primary windings increase the input voltage, while more secondary windings decrease it.