Carbon film resistors are a type of resistor made of a carbon film deposited on an insulating substrate. They have been widely used in electronics due to their low cost, stability, and accuracy.
Carbon film resistors are created by electrochemically etching the substrate and then depositing a thin film of carbon onto the surface. The resistive value of the resistor is determined by the thickness of the deposited film. This film can be applied in various thicknesses to create different resistive values and tolerances.
Carbon film resistors provide several benefits due in part to their construction. For example, they are more vibration resistant than most other types of resistors, as the carbon film adds additional durability. The resistive coefficient of the carbon film resistors is also higher, leading to a more stable resistance value over a range of temperatures. In addition, carbon film resistors are relatively smaller than most other types of resistors, making them ideal for applications with limited space.
Carbon film resistors also have their drawbacks. For example, they are not as reliable as metal film resistors, as they have a lower temperature cycle rating and are not able to handle as much power. In addition, the accuracy of carbon film resistors can be affected by temperature changes, aging, and corrosion.
Overall, carbon film resistors are an economical and effective resistor solution for electronics. While they are not as reliable as metal film resistors, their low cost, small size, and higher resistive coefficient make them a good choice for many applications. They are also relatively easy to manufacture, making them widely available and often the first choice for cost-conscious designers.
