In this tutotrail, we are going to learn about Basic of Transformer.
It is a device or a machine that transfers electrical energy from one electrical circuit to another electrical circuit through the medium of magnetic field & without a change in the frequency.
The electric circuit which receives energy from the supply mains is called primary winding & the other circuit which delivers electric energy to the load is called the secondary dg. So it is an electromagnetic energy conversion device (Energy received by primary is first converted to magnetic energy & it is then converted to useful electrical energy in other circuits like secondary & tertiary.
· If N1 = Primary winding turns
N2= Secondary winding turns
N1>N2 = Step down
N1<N2 = Step up
Note that a step up transformer can be used as the step down transformer, if supply is changed from one side to other side, so from this we can say that. It is better to use terms like low voltage winding & high voltage winding for the referring to the winding of particular transformer.
Transformers are widely used in both low & high current circuits:
Example- Electronic, measurements & control circuits = Low circuits
Power circuits = high circuits. High possible efficiency: (no moving parts)
Negligible amount of maintenance & supervision.
How transformers are used?
Generally insulation considerations limit the generation voltage of alternator to 11 to 22 kV. So to reduce the losses on transmission line, this voltage is stepped up to higher voltage. As power is same to be transferred is same ; P = vi As voltage increases , current decreases, so I2R losses decreases around 400kv or even higher. Whatever the electrical energy is required. t/f‘s are installed to step down the voltages suitable for its utilization purposes etc. So with this we can understand that A.C. system is more popular than D.C. system.
Important tasks performed by transformer are:
It is use for Step Up & Step down voltage & current level in low & high current circuits.
For matching the impedance a source its load for maximum power transfer in electronic control circuits.
For isolating D.C. while the flow of A.C. between two circuits for isolating from one circuit to other.