The transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. The main components are the primary coil, the secondary coil, and the iron core (magnetic core). The main functions are: voltage conversion, current conversion, impedance conversion, isolation, voltage regulator (magnetic saturation transformer) and so on. According to the use, it can be divided into: power transformers and special transformers (electrical furnace transformers, rectifier transformers, power frequency test transformers, voltage regulators, mining transformers, audio transformers, intermediate frequency transformers, high frequency transformers, impact transformers, instrument transformers, electronic transformers , reactors, transformers, etc.). Circuit symbols are often used as the beginning of a number. Examples: T01, T201, etc.
The transformer is used to change the voltage of the AC and is formed by the iron core and the coil wire. It can not only change the voltage of the alternating current, but also change the impedance and change the current when the power is not exceeded.
The use of transformers is different in different environments, such as:
1, remote input electrical lines, in order to reduce the loss of the line, from the power plant out of power, must first boost to tens of thousands of volts (such as 11KV), reach the destination, and then step down (220V).
2, in the electronic amplifier circuit, in order to achieve the least energy transfer between the two-wire amplification, impedance matching, with the transformer connection, can play a role in changing the impedance.
3. When welding, the current required between the electrode and the weldment is large (tens to hundreds of amps), and the voltage is very small (few volts). A welder is a transformer that turns a high voltage (such as 220V) into a low voltage. And without changing the power, a large current is generated at the output.
4. Sometimes, different voltages are needed in an environment, and the transformer can be made into multi-winding or mid-tap type. And then produce a variety of voltages.
5. In the AC voltage regulator, the number of turns of the output coil is immediately changed to achieve the purpose of adjusting the output voltage.