Learn More About Resistors
When you talk about electronics, what is the first component that will pop in your mind? Most people will say, resistors. Just like any other components, resistors come in a wide range of shapes, sizes, capacities, and types. This is not just for the sake of design but each has corresponding values for resistor noise, tolerance, wattage rating, frequency response, reliability, temperature, and voltage coefficient, which means you must know what resistor to use for your specific needs. To be able to do this, you should have knowledge about resistors.
Carbon Composition Resistors
The carbon composition, also known as a carbon resistor, is used to reduce the electric current flow to a certain level. Due to its fairly low cost and dependability, carbon composition resistors used to be the most common type of resistors used in electronics. Carbon resistors consist of a solid cylindrical resistive element usually made from the mixture of carbon or graphite powder with fixed wire leads or metal end caps. The carbon powder serves as a good conductor of electric current. The resistance of the carbon composition resistor depends on the ratio of carbon to the filler materials. However, this type has disadvantages such as poor stability and carbon composition has a problem with water absorption.
Carbon Film Resistors
The carbon film resistor is a type of fixed resistor that uses carbon film to restrain the electric current to a certain level. These types are widely used in the electronic circuits. The carbon film acts as resistant material to the electric current. The resistance of the carbon film resistor has a reverse proportion to the thickness of the carbon film layer. It generates less noise than a carbon composition resistor but has a high negative temperature coefficient of resistance.
Metal Film Resistors
A resistor that uses metal film to hinder the flow of electric current to a certain level is called a metal film resistor. The metal film resistor is the same as the carbon film resistor except for the material used in constructing the film is different. From the name itself, it uses metal alloys as the resistant material instead of carbon. Metal film resistors have a low-temperature coefficient of resistance which does not change easily with the change in temperature.
A wirewound resistor is a type of passive component that uses metal wires to reduce the flow of electric current to a certain level. The wire wound resistor is made by coiling the metal wire (generally a nickel-chromium alloy) around a metal core (ceramic bobbin). Here, a metal wire is used as the resistance element and the metal core serves as the insulating material. Wirewound resistors are not suitable for high inductance and capacitance due to the nature of their construction, which limits them to low-frequency applications. Wirewound resistors can be used for various applications like telecommunication, computers, current/voltage balancing, and current sensing.
A potentiometer is a three-terminal resistor with which the resistance is manually varied to regulate the flow of electric current. Potentiometers are generally used for analog user inputs such as volume controls, televisions, and computers to control the picture contrast and brightness.
Other Resistor Types
There are even more variants of resistors such as thin film, thick film, metal foil, oxide, shunts, cermet, and grid resistors.
This article made us realize that almost all our devices use resistors. Therefore, we can say that resistors are beneficial to our life and we must be grateful that they exist.