What is a Transformer

A transformer is an electrical device which is used to transfer electrical energy between two or more circuits. Transformers are used to increase or decrease alternating voltage according to our need. Transformers are widely used for transmission of AC current. It consists of two or more coils of wire which are used to transfer electrical energy by means of changing the magnetic field. A transformer operates by the principals of electromagnetic induction which is in the form of mutual induction. Transformers can increase or decrease the voltage or current levels without changing its frequency or the electrical power being transferred. A transformer size can vary from small to really big one.



it is designed to convert high voltage low current to low voltage high current


It is designed to convert low voltage high current to high voltage low current


  • Autotransformer – transformer in which part of windings is common in primary and secondary due to that efficiency increases size decreases and higher voltage regulation

  • Capacitor voltage transformer – capacitor divider is used in this to reduce high voltage before application to the primary winding

  • Scott T transformer – it is used for phase transformation from two phases to three phases and vice versa

  • Polyphase transformer – a transformer which has more than one phase

  • Resonant transformer – it uses resonance to generate a high secondary voltage

  • Audio transformer – it is used in audio equipment

  • Output transformer – it is used to match the output of a valve amplifier to its load

  • Instrument transformer – it is used to represent voltage, current, or phase position of high voltage or high power circuits accurately


• Transformers are used widely in electronic products to decrease the supply voltage to a level suitable for low voltage circuits they have

• It isolates end user from contact with supply voltage electrically

• Long distance transmission of electrical energy is done by transformers

• A transformer is used to decrease power loss by transforming power to a higher voltage

• Signal and audio transformer are used to couple stages of amplifiers and it would match to devices such as microphones and record players

• By the help of an audio transformer, a two-way conversation can be done in a single wire during a telephone conversation

• Transformers are used in medical equipment to isolate the user from a direct current

• It is used for impedance matching

• It is used in voltage regulators and power supplies…