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What are the Characteristics of a Carbon Composition Resistor?
A resistor is a type of passive electronic component, typically implemented within a circuit for the means of establishing electrical resistance. Depending upon the type of resistor and its characteristics, such components may reduce current flow, divide voltages, adjust signal levels, bias active elements, terminate transmission lines, and more. The carbon composition resistor (CCR) is a common type of fixed value resistor, meaning that their resistance remains steady throughout operations. As a widely used circuit element, it can be beneficial to familiarize oneself with their design, functionality, and applications.
For their construction, carbon composition resistors are produced from a solid cylindrical resistive element that is embedded with wire leads or metal end caps. To construct the resistive element, finely powered carbon and an insulating material such as ceramic is mixed together before being bound with a resin. To create a set resistance value, the ratio of powdered ceramic and carbon is controlled. With more carbon, more conductivity would be achievable. With more ceramic, meanwhile, resistance values may be bolstered. Once the component is bound and metal end caps or wires are attached, a plastic or paint coating is implemented for protection. Lastly, color-coding is then applied so that the carbon composition resistor’s value can easily be determined.
With their construction and resistive qualities, carbon composition resistors are often known for their ability to withstand high energy pulses with ease. Due to their materials, pulses are conducted by the body of the component so that current may flow through it. As the thermal mass of the resistor is high, such components exhibit a high energy capability. When compared to similar resistor types like the wirewound resistor, carbon composition resistors are advantageous due to their ability to be manufactured with higher resistance values. Despite this, they tend to lack in their temperature coefficient, voltage dependence, noise, and load.
While carbon composition resistors were once popularly used for consumer electronics, their low stability in terms of resistance values has made them unsuitable for more modern, high precision applications. This is due to the varying heat expansion properties of the materials found within the carbon composition resistor, leading to stresses as materials heat and cool down. As such, the contact between particles may adjust, which will result in changes in the resistance value. Such resistors are also affected by internal moisture content that may arise from being in a humid environment. As soldering heat creates non-reversible changes in resistance values, they can lose their accuracy over time and begin to falter in various applications. Therefore, they should always be well protected from environmental conditions such as high humidity.
Despite their compact construction, carbon composition resistors are still very optimal for taking on high energy pulses. As a result, they can be found within a variety of applications related to circuit protection for surges and discharges, high voltage power supplies, current limiting, strobe lighting, welding, and more. One major use of carbon composition resistors is within medical defibrillators, those of which feature sensitive measurement equipment that must be guarded from the high energy pulses generated by such systems. Placed in the equipment or leads, the carbon composition resistors then resist the high pulse energy that is released. While still readily available, carbon composition resistors can be more expensive than other options. While serving well in various applications, carbon composition resistors also find popular use in vintage electronic equipment where one may be concerned with authenticity.
Whether you are interested in procuring an adapter resistor, amplifier resistor, baroresister, current sense resistor, or other electronic component, there is no better alternative to NSN Gamut. NSN Gamut is a website owned and operated by ASAP Semiconductor, and we are your sourcing solution for top quality electronic components that you can steadily rely on with ease. With our strict NO CHINA SOURCING pledge, we ensure that all items come from a dependable manufacturer and ship alongside all qualifying certifications and manufacturing trace documentation as applicable. As a result of our dedication to rigorous quality control standards and export compliance initiatives, we proudly conduct operations with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation. If you are ready to initiate the purchasing process or would like to speak to one of our representatives, give us a call or email at your earliest convenience and we would be more than happy to assist you however necessary.
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