Learn Different Types of Resistor- Linear & Non-Linear in Detail

Have you ever thought about how the flow of current is regulated in day-to-day life? In physics, we have learned that the flow of current can be regulated using a resistor. A component or gadget with a known resistance value is called a resistor. Resistors are used to oppose or limit the flow of electric current through them. Resistors come in a variety of sizes, shapes, and materials. Read on to explore more about the types of resistors!

Types of Resistor

Resistors come in two different categories.

• Linear resistor
• Non-linear resistor

Linear Resistors

Linear resistors are those whose values fluctuate in response to temperature and applied voltage. There are typically two types of resistors with linear characteristics.

• Fixed Value Resistors.
• Variable Resistors.

Fixed Value Resistor

The resistor that is by far the most frequently used is a fixed resistor. To create the ideal circumstances in a circuit, they are utilised in electronic circuits. Their values are chosen at the circuit’s design phase, thus the circuit shouldn’t ever need to be adjusted by changing them. The various varieties of resistors that can be utilised in various situations are listed below along with more detailed descriptions.

Carbon Composition Resistor

The carbon composition resistor is a resistor that was formerly widely used. It was the primary type of resistor, but it is now rarely used because other types of resistor offer higher performance, are smaller, and are also less expensive.

Carbon granules and a binder are combined to create carbon composition resistors, which are then shaped into tiny rods. By today’s standards, this sort of resistor was huge and had a significant negative temperature coefficient. Due to heat or ageing, the resistors also experienced significant, unpredictable, permanent variations in resistance. Additionally, because the carbon and binder are granular, there is a lot of noise produced as the current flows.

Metalized Resistor

The most popular kind of resistor in use today is this kind. This resistor type uses a metal oxide layer that has been placed on a ceramic rod rather than a carbon film. Similar to carbon film, a helical groove can be sliced into the film to change the resistance. The film is once more shielded by a conformal epoxy coating.

This sort of resistor performs significantly better than any carbon-based resistor due to its temperature coefficient, which is approximately + or – 15 parts per million per degree Celsius. Additionally, this sort of resistor may be made to considerably tighter tolerances, with conventional ranges of 5% or even 2% and available variants of 1%. They also have far less noise than carbon-type resistors, but the metal film resistor has largely replaced them.

Wire Wound Resistor

High-power applications typically use this type of resistor. These resistors are created by winding resistance wire with a higher resistance than usual on a former.

The more premium varieties can have vitreous or silicone enamel applied to them, and they are coiled on ceramic formers. Although this will depend on a variety of parameters such as the former wire used, etc., this resistor type is suitable for high powers and demonstrates a good degree of reliability at high powers coupled with a relatively low level of temperature. Some variants of wire-wrapped resistors are created to be mounted onto a heatsink to guarantee that the power is dissipated into metals because they are frequently used in high-power applications.

Although the inductance can be somewhat reduced by winding various sections of the resistance wire in opposite directions, they are not appropriate for operation above low frequencies due to their wound structure.

Thin Film Resistor

Thin film resistors are of 2 types as shown below:

• Metal Film Resistor

The metal film resistor and the metal oxide film resistor are quite similar. Both the performance and the appearance are extremely similar. As the name implies, this type of resistor employs a film rather than a metal oxide film. The utilisation of metals like nickel alloy is possible. When a leaded resistor is required, the metal film resistor is the kind that is most frequently used.

• Carbon Film Resistor

During the early stages of transistor technology, when power levels tended to be lower, this kind of resistor was first developed. Resistor with carbon film displaying the body and colour-code rings.

A hydrocarbon is cracked onto a ceramic former to create the carbon film resistor. The resistance of the deposited film that resulted was set by helix the film. Due to their high inductive properties, these resistors were not very useful in many RF applications. The temperature coefficient that they displayed ranged from -100 to -900 parts per million per degree Celsius. Either a ceramic tube or a conformal epoxy covering protects the carbon film.

Thick Film Resistor

Thick film resistors are of two types as shown below:

• Metal Oxide Resistor

These are fixed and axial resistors. They are mostly made up of ceramic rods which are coated with a thin film of metal oxides, like tin oxide.

• Metal Strip Resistor

Metal strip resistors convert current into voltage that can be easily monitored. This enables the controller circuit to track current flowing through the circuit. These are low-power resistors.

• Fusible Resistor

The fusible resistor is used to safeguard the circuit against the excessive current.

• Cermet Resistor

These are the flame and heat resistant resistors. They are built to handle large amounts of power flowing through it without being damaged.

Variable Resistor

• Potentiometer

It consists of two fixed and one changeable terminal. The resistance of the potentiometer is changed if the path of the wiper is moved. If the resistance of the potentiometer is increased the current decreases. Thus they are inversely proportional to each other.

• Rheostats

The word rheostats are derived from the Greek word. It is similar to a potentiometer. In rheostat, we only use two terminals for doing the task.

• Trimmers

Trimmers are potentiometers that occasionally need to be adjusted. They frequently need a specialised instrument for adjustment and are used to calibrate a device or circuit after production.

Also, learn about Resistor Colour Codes

Non-Linear Resistors

• Photoresitor

Resistors or photoresistors that are light-dependent alter their resistance in response to the amount of light. They are employed in numerous sensor applications and frequently offer a very cost-effective option. Light-dependent resistors are inexpensive and simple to use, but they lag in their response to changes in light.

• Thermistor

The term ‘thermistor’ refers to heat-sensitive resistors. The thermistor’s resistance varies with temperature. Some thermistors, known as NTC thermistors, have a low coefficient of thermal expansion, while others, known as PTC thermistors, have a positive coefficient of temperature.

• Surface Mount Resistors (SMD resistors)

SMD resistors, often known as surface mount resistors, have a rectangular shape. Electronic parts designed for Surface Mount Technology (SMT) are known as SMDs.

• Varistor resistors

Varistors come in a variety of configurations. These electrical parts change their resistance in response to the applied voltage, which makes them useful for surge and spike protection. They are frequently referred to as Movistors, which is short for Metal Oxide Varistor.

Explore the Testbook app for more exciting physics terms! There are various practice assessments and well-curated written notes available to assist you in your studies. The Android versions of the phone support this app. Install the Testbook App right away!