|
Resistors are considered to be the most fundamental and commonly used electronic component. There are two types of resistors – fixed and variable. Fixed resistors have a defined ohmic resistance that cannot be adjusted. The primary job of a resistor is to resist or regulate the flow of electrons by using specific types of conductive material. This material not only defines their level of resistance but is also how fixed resistors are separated into broad categories. The first group of fixed resistors is carbon resistors. Carbon resistors are extremely inexpensive to product which is why they are a preferred general purpose option. Their resistive elements are created from a mixture of carbon or graphite that is finely ground and ceramic powder. The ceramic or clay is used to bind all of the carbon dust together. Carbon resistors are a low type resistor which makes them good for high frequency applications. Unfortunately, they also suffer from noise and instability when they get too hot. They also do not offer a high level of current precision. The second group is film fixed resistors. This is a generic term which covers metal, carbon, and metal oxide film resistors. The thickness and type of the film largely determines the resistive value of the resistor. The method of manufacture allows for more precise tolerances than basic carbon resistors. The ability to alter the thickness also makes it easier to achieve a higher maximum ohmic value compared to other resistors. The third group is wirewound resistors. They are manufactured by winding a thin metal alloy wire onto an insulating ceramic in a spiral helix. Normally the wire is Nichrome. This type of fixed resistor is primarily used for extremely low ohmic currents but offer the unique value of being highly precise. This is because the gauge of the wire and number of turns makes it ideal for measuring circuits. Additionally, wirewound resistors are able to handle much higher currents than other resistors with the same ohmic value. This is because they can be pressed into an aluminum heat sink body to increase the overall surface area. A greater surface area allows for greater heat loss and cooling. This specific type of wirewound resistor is typically called Chassis Mounted Resistors. There are a variety of different types of fixed resistors available ranging from extremely low cost, general purpose options to more expensive, high precision options. The key similarity is all fixed resistors have the same resistance value regardless of the current supply frequency. About the Author: My name is Rosario Berry, a professional freelance writer, like to introduce Rara Electronics Corp. . There are a variety of different types of Fixed Resistors available ranging from extremely low cost, general purpose options to more expensive, high precision options.
Related Articles -
fixed resistors, wirewound resistors, film fixed resistors, carbon resistors, electronic component,
| 
