Introduction to Transformers

Definition

• Transformer: A static device that transfers electrical energy from one circuit to another without changing frequency and magnitude of power.
• Constant Frequency Device: Frequency remains constant in a transformer.
• Constant Power Device: Power magnitude does not change in a transformer.

Energy Conversion

• Electromagnetic Energy Conversion:
  • Externally: Not an energy conversion device.
  • Internally: Converts electrical energy into magnetic energy and back to electrical energy.

Basic Structure of Transformer

• Magnetic Core: Central part of the transformer.
• Windings:
  • Primary Winding: Connected to the source.
  • Secondary Winding: Connected to the load.

Operation

• When voltage flows through the conductor, flux is produced.
• The produced flux links with the secondary winding.

Phase Shift

• Phase Shifting Device:
  • The phase shift between input and output is 180 degrees.
  • Example: Input voltage (V1) and output EMF (E1) are 180 degrees apart.
• Similar phase shift in transistors.

Characteristics of Transformers

• Singly Excited Device: Requires only a single source for excitation.
• Constant Flux Device:
  • Flux depends on magnetic flux density and cross-sectional area.
  • Magnetic flux density depends on the material used.
  • Cross-sectional area remains constant once in operation.

Summary

• Transformers are important devices in electrical engineering with specific characteristics that include constant frequency, constant power, energy conversion, phase shifting, and constant flux.