What is the function of a transistor?

A transistor, also known as a transistor, is one of the core components in electronic circuits. Its main function is to control and process current and signals, playing an irreplaceable role in modern electronic devices.
Simply put, a transistor is like a current valve. It controls the on/off or change of a large current through a small current or voltage signal. This characteristic of "controlling the big with the small" enables it to have the following key uses:
Firstly, transistors are commonly used for signal amplification. In radio, audio equipment, or sensor circuits, weak electrical signals are amplified by transistors before they can drive speakers or be recognized and processed by subsequent circuits. This is one of the most classic applications of transistors.
Secondly, the transistor can serve as an electronic switch. By controlling the input signal, it can quickly connect or disconnect the circuit, achieving the on/off function of the circuit. This type of switch is widely used in digital circuits, power control, and microprocessor interfaces, with a speed much higher than mechanical switches.
In addition, transistors can also be used for impedance matching, signal modulation, and oscillation circuits. For example, in radio transmissions or oscillators, transistors help generate and stabilize high-frequency signals. In the power circuit, it can also participate in voltage regulation and current protection.
It can be said that from mobile phones, computers to industrial equipment, almost all electronic product circuit boards cannot do without transistors. It realizes signal amplification, circuit switching, and precise adjustment of various electrical quantities, laying the foundation for modern electronic technology. It is precisely with its stable and reliable control capabilities that this small component continues to drive the development of the electronics industry.