How transformer works

Generated DC current is constant therefore induced magnetic field stays constant.

AC current generated by AC Generator increase and decrease in strength. and changes polarities.

Magnetic field changes.

 

The current on second coil will be created by fluctuating magnetic field induced by first coil. 

: The key component here is that the magnetic field is changing polarity as well as intensity. This change in intensity and direction of the magnetic field constantly disturbs the free electrons in a secondary coil and this forces them to move. This movement is known as electromotive force or EMF.

 

 

 

Electromotive force does not occur when we pass the DC currnet through the primary coil, and that's because the magnetic field is constant. Only occurs when the primary circuit is opened and closed or when the voltage is increasted or decreased.

 

>>Arc, when inductor is found in the circuit, when open the circuit if there is significant voltage change, arc works as a conductor to open the circuit linearly. 

 

 

 

The magnetic field is wasted because it's not reaching the range of secondary coil.

To prevent this, a core of ferromagnetic material such as iron, in a loop between the primary and secondary coils. Now this loop guides the magnetic field along a path to the secondary coil so that they will share the magnetic field and this makes the transformer much more efficient.

 

Some energy will be lost with Eddy Currents where the current swirls around the core and this heats up the transformer which means that the energy is lost as heat.

To reduce the Eddy currents, laminated sheets of iron is used to form the core.

 

 

 

Step up transformer:

The number of turns within the primary coil is less than that within the secondary's.

zB. A power station will use the step up transformer to increase the voltage to reduce the current as this reduce the losses for the long transmission cables. 

 

Step down transformer:

The number of turns within the primary coil is more than that within the secondary's

zB. In the city, the voltage needs to be dropped down to make it safe and usable by buildings and homes.

 

 

One of the most commonly used commercial transformers are three phase transformer.

Outer coils are Higher voltage coils and inner coils are lower voltage coils.

 

There are many different configuration to connect the two sides.

<Commonly used>

Primary-Delta

Secondary-Wye(Star)

 

The centre point of the Wye connection is often grounded, which allows for a neutral line to also be connected.

 

 

 

Studied from

The Engineering Mindset

(theengineeringmindset.com)