Resistors, principles, types, and applications

Resistance is an electronic component whose main function is to obstruct the flow of current. This article will introduce the principle, types, usage methods, and precautions of resistors in various applications

1、 The principle of resistance

The working principle of a resistor is simple, it restricts the flow of current through the resistance value of its own material. A resistor is composed of two conductor materials, usually one is a conductive metal (such as copper or aluminum) and the other is a non-conductive material (such as nickel or zinc oxide). When current passes through a resistor, electrons jump back and forth between two materials, but due to the different resistance values of different materials, some electrons are blocked from passing through, forming a resistance

2、 Types of resistors

1. Fixed resistor: The resistance value of a fixed resistor is fixed and is usually used as a voltage divider or current limiter in circuits. They come in various sizes and power levels to choose from, including common surface mount packaging (SMT) resistors such as 0402, 0603, 0805, etc

2. Variable resistor: A variable resistor (also known as a sliding resistor) is a resistor whose resistance can be adjusted. Its principle is to change its resistance by changing the number of turns in the coil connected to the circuit. This type of resistor is commonly used in control systems to adjust voltage or current as needed

3. Thermistor: The resistance of a thermistor changes with temperature. They are commonly used in temperature sensors, such as constant temperature water baths or refrigerators, to control the flow rate of refrigerants

3、 Application of resistors

There are many applications in electronic devices that use resistors. Here are just a few examples:

1. Power filter: Using resistors on the power line can reduce noise and stabilize voltage output

2. LED driver circuit: By controlling the current through appropriate resistance values, the LED bulb can emit the correct brightness and color

3. Motor control: In the motor control system, variable resistors can be used to adjust the speed and torque of the motor

Although resistors may seem simple, they have a wide range of application values. Understanding different types of resistors and their working principles can help us better select suitable components to meet specific needs when designing circuits