A transformer is a static device that transforms power from one circuit to another without changing the frequency. It uses a primary coil connected to a power supply and a secondary coil connected to a load to induce a voltage in the secondary coil through electromagnetic induction from the primary coil. There are two main types of transformers: step-up transformers which have fewer turns in the primary coil to increase voltage, and step-down transformers which have fewer turns in the secondary coil to decrease voltage.

2. Transformer: A Transformer is a device that transforms power from one circuit to other circuit without change in frequency. It is a static device and all currents and voltages are AC

3. Transformers - used to supply the different voltage requirements of the appliances we use from the mains supply. Door Bell (6V) Step-Up Transformer Step-Down Transformer Main Supply (230V) Example: Television Set (>1k V)

4. 06/15/11 Primary Coil - Connected to electrical supply Secondary Coil - Connected to electrical load (eg. Lamp, door bell, television set) The structure of transformer: ~ Supply ~ Electrical Load Primary Coil Secondary Coil Soft Iron Core

5. Transformers Types: Step-Up Transformer - Lesser turns in primary Step-Down Transformer - Lesser turns in Secondary Primary Coil Secondary Coil Load Supply Secondary Coil Primary Coil Load Supply

6. Working principle When the switch is closed: Current in primary coil increases Creates increasing magnetic field in primary coil Induces voltage in secondary coil Lamp lights up Primary Coil Secondary Coil Soft Iron Core ac supply

7. There are two general types of transformers Core type transformer Shell type transformer These two differ by the manner in which the windings are wound around the magnetic core. In order to reduce the eddy current losses, the core is laminated. In order to reduce the core losses, transformers have their magnetic core made from cold-rolled grain-oriented sheet steel (C.R.G.O). Transformer Construction:

8. Transformer Construction: Core Type Transformer:

9. Transformer Construction: Shell Type Transformer:

10. There are two types of windings employed for transformers. concentric coils. Interleaved coils. The concentric coils are used for core-type transformers and interleaved coils for shell-type transformers Transformer Construction: