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A transformer is an essential electrical device used to transfer electrical energy from one circuit to another through electromagnetic induction. It consists of two or more coils of wire, known as the primary and secondary windings, wound around a core made of ferromagnetic material, such as iron.


  1. Voltage Transformation: The primary function of a transformer is to change the voltage level of an alternating current (AC) electrical signal. Depending on the winding ratio between the primary and secondary coils, a transformer can step up (increase) or step down (decrease) the voltage.
  2. Electromagnetic Induction: When an alternating current flows through the primary winding, it generates a changing magnetic field in the core. This magnetic field induces a voltage in the secondary winding through electromagnetic induction, resulting in electrical energy transfer from the primary to the secondary circuit.

Components and Operation:

  • Primary Coil: The primary coil receives the input electrical signal and is connected to the power source. When current flows through the primary coil, it generates a magnetic field in the core.
  • Secondary Coil: The secondary coil is connected to the load or the circuit requiring the transformed voltage. The induced voltage in the secondary coil depends on the turns ratio between the primary and secondary windings.
  • Core: The core provides a path for magnetic flux generated by the current in the windings. It is typically made of laminated iron or other ferromagnetic materials to enhance magnetic coupling and reduce energy losses.


  1. Power Distribution: Transformers are widely used in electrical power distribution systems to step up the voltage for efficient long-distance transmission and step down the voltage for safe distribution to homes, businesses, and industrial facilities.
  2. Electronics: Transformers are used in various electronic devices, such as power adapters, voltage regulators, and audio equipment, to adapt voltage levels and isolate circuits.
  3. Ignition Systems: In vehicles, ignition coils are a type of transformer used to step up the voltage from the battery’s low voltage (typically 12 volts) to a much higher voltage (e.g., 20,000 volts or more) required to produce the high-energy sparks needed for combustion in the engine’s cylinders.


  • Voltage Regulation: Transformers provide efficient and reliable voltage regulation, allowing for the safe and efficient transfer of electrical energy across different voltage levels.
  • Isolation: Transformers provide electrical isolation between the primary and secondary circuits, protecting sensitive equipment and users from electrical hazards and interference.

Transformers are essential electrical devices that enable efficient voltage transformation and electrical energy transfer through electromagnetic induction. They play a crucial role in power distribution, electronics, and various industrial and automotive applications, providing voltage regulation, isolation, and efficient energy transfer.

See Related Terms:

  • AC Transformer
  • Air transformer
  • Audio-frequency Transformer
  • Balancer Transformer
  • Bar-type Current Transformer
  • Biasing Transformer
  • Booster Transformer
  • Buck Transformer
  • Carbon Pile Voltage Transformer
  • Delta Transformer
  • Ignition transformer
  • Quadrature Transformer
  • Voltage transformer
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