How does a switch work? How does a switch work?

A switch is an electrical component used to control the on and off of a circuit. Its working principle is mainly to control the conduction state of the conductive material to achieve the on and off of the circuit. The switch plays a very important role in the circuit, and can realize the functions of circuit switch control, circuit branch selection, circuit protection, etc.

The working principle of switches can be divided into two types: mechanical switches and electronic switches. Mechanical switches use mechanical structures to turn on and off circuits, while electronic switches use semiconductor devices to turn on and off circuits.

The working principle of a mechanical switch is to control the conduction state of a conductive material through a mechanical structure. When the mechanical switch is in a closed state, a path is formed between the conductive materials, and current can flow; when the mechanical switch is in an open state, the path between the conductive materials is disconnected, and current cannot flow. A mechanical switch is usually composed of conductive materials, contacts, springs, etc. When the mechanical switch is pressed or pulled open, the contacts connect or disconnect the conductive materials, thereby realizing the on and off of the circuit.

The working principle of an electronic switch is to realize the on and off of a circuit through a semiconductor device. Common electronic switches include transistor switches and field effect transistor switches. A transistor switch realizes the on and off of a circuit by controlling the base voltage of the transistor. When the base voltage is high, the transistor is turned on and the circuit is closed; when the base voltage is low, the transistor is turned off and the circuit is disconnected. A field effect transistor switch realizes the on and off of a circuit by controlling the gate voltage, and its working principle is similar to that of a transistor switch.

Switches are widely used in circuits. They can be used to control lights, electrical equipment, motors, etc. They can also be used to realize circuit branch selection, protection and other functions. In modern electronic devices, switches have become one of the indispensable components, and the research and application of their working principles are also constantly developing and improving. I hope that through the introduction of this article, readers will have a deeper understanding of the working principle of switches.