How transformer works

What is a TRANSFORMER ?

A transformer is an electrical device that transfers electrical energy at one voltage from one circuit to other at a different voltage merely by magnetic coupling; the transfer of energy doesn’t involve any kind of motion.

Transformers are analogous to gear box (used to convert torque and hence speed). Transformers step up or step down the voltage and therefore vary the current. As the product of speed and torque remains constant, product of voltage and current also remains constant.

Transformers utilises the principle of electromagnetism given by Faraday’s law. A conductor carrying changing current carrying sets up a changing magnetic field around it. When a second conductor is placed in this varying magnetic field, voltage will be induced into it

When an AC voltage is applied to one (primary) coil, the varying magnetic field is set up around the coil. By virtue of mutual induction, it creates an AC voltage in the other (secondary) coil. A transformer can also be used with pulsating dc, but a pure dc voltage cannot be used, since only a varying voltage creates the varying magnetic field which is the basis of the mutual induction process.

An ideal transformer has infinite winding reactance, zero winding resistance, zero leakage inductance and zero winding capacitances. Voltage ratio is equal to the turns ratio under all loading conditions.

How Does a Transformer Work?

A transformer is an electrical device that takes electricity of one voltage and changes it into another voltage. You'll see transformers at the top of utility poles and even changing the voltage in a toy train set.

Basically, a transformer changes electricity from high to low voltage using two properties of electricity. In an electric circuit, there is magnetism around it. Second, whenever a magnetic field changes (by moving or by changing strength) a voltage is made. Voltage is the measure of the electric force or "pressure" that "pushes" electrons around a circuit.

If there's another wire close to an electric current that is changing strength, the current of electricity will also flow into that other wire as the magnetism changes.

A transformer takes in electricity at a higher voltage and lets it run through lots of coils wound around an iron core. Because the current is alternating, the magnetism in the core is also alternating. Also around the core is an output wire with fewer coils. The magnetism changing back and forth makes a current in the wire. Having fewer coils means less voltage. So the voltage is "stepped-down."