Online Free Computer Course

• It is an electric device that transfers energy between two circuits using Electromagnetic Induction. 
• Operation of transformer 

1. The operation of a transformer can be explained with the help of these two laws: Electric current produces magnetic field across the conductor and a change in magnetic field induces voltage at the ends of the conductor. 

• Features of Transformer
  

1. There is no copper loss in the windings 
2. There is no inductive loss 
3. Flux is present only within the magnetic core 

• Construction of Transformer

Based on the application, a transformer consists of a core made up of ferromagnetic or ceramic material and a coil made up of some insulating magnetic material or copper wires. Transformer oil is used for cooling transformer

• Losses in a Transformer 

• These are the losses in a transformer: 

1. Winding loss 
2. Hysteresis loss 
3. Eddy current loss 
4. Hum Stray loss 

• Winding losses: Current flowing through windings causes heating and losses due to heating. 
• Hysteresis losses: Each time the magnetic field is reversed, some energy is lost. It is hysteresis loss. 
• Eddy current losses: Eddy currents are present in the ferromagnetic core and cause resistive heating in the core. 
• Hum: Magnetic flux causes the core to physically expand slightly and it results in a humming noise. 
• Stray losses: Inductive leakage and radiation losses are all stray losses in an inductor.

                   Types of Transformers

• Based on the purpose of transformers, they are classified into Power transformers, Instrument transformers, RF transformers, Audio Transformers.

1. Power Transformer: Used for high voltage transmission purposes. 
2. Instrument Transformer: They are used to operate instruments at high voltage, high current cicuits and safely isolate the control circuit. 
3. RF Transformer: Transformers used in Radio Frequency applications. 
4. Audio Transformer: They block radio frequency signals, split and combine audio signals.