Working principle of power transformer
A power transformer is composed of an iron core (or magnetic core) and two or more coils, which are divided into primary and secondary coils. When an alternating current passes through the primary coil, it generates a changing magnetic field in the iron core. The changing magnetic field will pass through the secondary coil, inducing voltage in the secondary coil.
The magnitude of the induced voltage is related to the turns ratio of the primary and secondary coils. If the secondary coil has more turns than the primary coil, the output voltage will be higher than the input voltage, and this type of transformer is called a step-up transformer. On the contrary, if the secondary coil has fewer turns than the primary coil, the output voltage will be lower than the input voltage, and this type of transformer is called a step-down transformer. The working principle of a power transformer can be explained by Faraday's law of electromagnetic induction, which states that a changing magnetic field will induce an electromotive force in a closed circuit. In a power transformer, changes in current in the primary coil generate a changing magnetic field, which in turn induces voltage in the secondary coil.
Power transformers play an important role in power systems and electronic devices. They can change the voltage level, enabling efficient and safe transmission and distribution of electricity. At the same time, power transformers can also achieve current regulation and impedance matching, thereby meeting the needs of various electrical equipment.