Transformers

1. Definition

1.1 Transformer

A transformer is an electrical device that transfers AC electrical energy between two or more circuits using electromagnetic induction.
It can increase (step up) or decrease (step down) AC voltage, while keeping the same frequency.

Transformer example

Transformer Symbol

Transformer symbol

1.2 Types of Transformers

  • Step-down : Converts high voltage AC to lower voltage AC (e.g., 230V → 12V).
  • Step-up : Converts low voltage AC to higher voltage AC.
  • Isolation : Same input and output voltage, but provides galvanic isolation for safety.

2. Features

  • Primary and secondary winding ratio : determines output voltage.
  • Power rating : in VA or watts (how much load it can supply).
  • Core material : laminated steel (low-frequency) or ferrite (high-frequency).
  • Frequency range : usually 50–60Hz for mains, higher for specialized transformers.

4. How to Use

Safety Note

Mains-voltage transformers can cause electric shock. Always disconnect power before wiring, and follow proper insulation and grounding practices.

4.1 Identify Windings

  • Primary winding : connects to the input source (e.g., mains AC).
  • Secondary winding : provides the output voltage.
  • Winding labels or datasheet will specify voltage ratings.

Transformer pinout

4.2 Typical Applications

  • Power supplies , converting mains AC to lower AC before rectification.
  • Audio coupling, matching impedance between audio equipment.
  • Electrical isolation, protecting sensitive circuits from dangerous voltages.
  • Signal transmission, in networking and communication systems.

5. Video Explanation

video coming soon