Carbon Resistors and Their Common Types

When managing an electrical circuit, resistors are components that serve to reduce current flow and adjust signal levels in order to further the safe and efficient distribution of power. Depending on the application that needs a resistor and its presented electrical ratings, a variety of resistor types and materials may be used in order to achieve varying operations and resistances. As one of the primary materials for manufacturing, carbon can allow for a number of robust resistors to efficiently manage the current loads of many different electrical systems.

The carbon composition resistor is a type of fixed resistor component, and it consists of a cylindrical element that has wires attached to it through leads or end caps. To best protect the resistor’s body without affecting its capabilities, a layer of paint or plastic may be implemented. In order to denote the values or ratings that specific carbon composition resistors can handle, color-coding may be placed on the painted or plastic body of the component. To manufacture a carbon composition resistor, powdered carbon is mixed together with an insulating material such as ceramic and then held together with a resin. By adjusting the ratio of carbon powder and ceramic, the resistance of the resistor can be adjusted as needed. If a particular circuit requires a carbon composition resistor with less resistance, one should choose a component that has been mixed with a higher ratio of powdered carbon.

As one of the early resistor types, carbon composition resistors still serve a variety of general applications. With newer resistor types often superseding the carbon composition resistor in regard to tolerance, stress, and voltage dependence, however, the electronic component is not implemented in systems as much as it used to be. Nevertheless, such resistors may still prove much use for power supplies and welding controls. They are also high in demand for many vintage appliances and electronics when there is a desire for authentic parts to carry out repairs.

With carbon film resistors, a ceramic carrier is encapsulated within a thin film of pure carbon. To adjust the resistivity of the component, the film may be made thicker or thinner as desired. As compared to the more conventional carbon composition resistor type, carbon film resistors are much lower in price, have a low tolerance, and produce less noise during their operation. With their various capabilities, carbon film resistors are often used for radar equipment, x-rays, and power supplies. To produce carbon film resistors, a ceramic carrier is placed within hydrocarbon gas at high temperatures and pressures. By utilizing a deposition process with crystalline carbon, the distribution is very precise across the substrate. As a result, the carbon film resistor is capable of operating with low noise.

The last primary type of carbon resistor is the carbon pile resistor, that of which is manufactured by compressing carbon disks together between metal contact plates. By adjusting the pressure of the contact plates, the resistivity of the carbon pile resistor can be raised or lowered. Carbon pile resistors often serve well for applications that require an adjustable load, such as being implemented within automotive battery testers. Such resistors can also serve well as a speed control for small motors.

By implementing resistors within an electronic circuit, current can efficiently be distributed to appliances and components for reliable operation. At AFR Enterprises, we offer our customers access to a wide variety of resistors and electronic components that have been sourced from top global manufacturers. As a leader among online parts distributors, we ensure that every item is subject to rigorous quality assurance testing, inspection, and cross-referencing before being sent out. Get started today with a personalized quote on the parts that you are interested in when you fill out and submit an Instant RFQ form as provided through our website.