TRANSFORMERS- INTRODUCTION AND WORKING PRINCIPLE

TRANSFORMER IS A STATIC DEVICE IN WHICH IT DOES NOT CONTAIN ANY ROTATORY OR MOVING PART.

IT IS USED TO TRANSFER ELECTRICAL ENERGY FROM ONE CIRCUIT TO ANOTHER CIRCUIT WITHOUT ANY CHANGE IN FREQUENCY AND POWER.

WE CANNOT GENERATE ELECTRICAL ENERGY EVERYWHERE,SO GENERATING ELECTRICITY AT SPECIFIC LOCATIONS REQUIRE TRANSMISSION AT LONG DISTANCES. THUS DURING TRANSMISSION, LOSSES OCCUR.

TRANSFORMERS CAN CHANGE THE VOLTAGE AND CURRENT LEVEL
IT CAN BOTH INCREASE AND DECREASE, DEPENDING ON ITS CONNECTIONS.

ON THE BASIS OF LEVEL, TRANSFORMERS ARE  GENERALLY CLASSIFIED INTO TWO TYPES:

• STEP UP TRANSFORMER (FOR INCREASING VOLTAGE LEVEL)
• STEP DOWN TRANSFORMER (FOR DECREASING VOLTAGE LEVEL)

WORKING PRINCIPLE OF TRANSFORMER

• TRANSFORMER IS BASED ON THE PRINCIPLE OF FARADAY LAW OF ELECTROMAGNETIC INDUCTION.

• WHEN THE PRIMARY WINDING IS CONNECTED TO AN AC SUPPLY, A CURRENT STARTS FLOWING THROUGH IT.

• THIS AC PRIMARY CURRENT PRODUCES AN ALTERNATING FLUX IN THE CORE
• SINCE THIS FLUX IS ALTERNATING AND LINKS WITH THE SECONDARY WINDING ALSO, SO INDUCES AN EMF IN THE SECONDARY WINDING, ACCORDING TO LAW OF ELECTROMAGNETIC INDUCTION.

• THUS DUE TO PRIMARY CURRENT, THERE IS AN INDUCED VOLTAGE IN THE SECONDARY WINDING DUE TO MUTUAL INDUCTION.

• HENCE THE EMF INDUCED IN SECONDARY WINDING IS CALLED MUTUALLY INDUCED EMF

• THUS ENERGY IS TRANSFERRED FROM PRIMARY WINDING TO SECONDARY WINDING WITHOUT ANY CHANGE IN FREQUENCY AND POWER.

• SINCE INDUCED EMF IS DIRECTLY PROPORTIONAL TO THE NUMBER OF TURNS IN THAT WINDING.

• HENCE MORE THE NUMBER OF TURNS MORE THE EMF WILL BE INDUCED.

THUS IN STEP UP TRANSFORMER,

                      PRIMARY WINDING TURNS <  SECONDARY WINDING TURNS

AND IN STEP DOWN TRANSFORMER,

                       PRIMARY WINDING TURNS >  SECONDARY WINDING TURNS

For understanding more clearly watch the video: