A carbon resistor is a type of fixed resistor. The resistor has been in existence for more than a century. Initially, resistors were manufactured without any coating. The only resistors available were wire wrapped and carbon composition. Carbon resistors are constructed of tiny carbon fragments with a binder in a cylindrical shape and baked with terminal lead at the other end.
Carbon composition resistors are commonly used in electrical circuits, and the vast majority of resistors are composed of metal or carbon films over a ceramic carrier. The carbon resistor's most important function is its capacity to withstand high energy pulses. The whole system of the carbon resistor carries the energy for the current running through it. Carbon resistors are available in a variety of physical sizes, with power dissipation limits ranging from 1 watt to 1/8 watt.
Many metals and alloys, including nichrome, brass, platinum, and tungsten, are utilised to provide resistance. However, when compared to resistors, most of the metals have low electrical resistance. This is because it is difficult to create high resistance without making the resistor bulky. Resistance is previously known to be exactly proportional to the product of the resistor's length and resistivity. Because a carbon resistor can give a high precision resistance value, it is commonly used to calibrate resistance.
Carbon resistors are inexpensive, small, and maybe directly inserted into circuit boards such as those used in tablets, mobile phones, and laptop CPUs. Because of all of these practical applications, they are favoured over metal wires, which are more expensive to make compared to carbon, which is abundant. The resistance is replicated by carbon resistors within the practical requirement.
Though carbon resistors may be made from a number of materials, some of the carbon resistor's components are listed below:
Carbon resistors are created using the deposition technique. The carbon layer is deposited on the ceramic body of the resistor during this procedure. Because the carbon film inhibits the flow of current, it is an essential component of the resistor. Hydrocarbons such as methane or benzene are cracked at a high temperature of 1000°C. The ceramic mould acts as an insulator against high temperatures or electrical current, and pure graphite is used for distribution over the ceramic body. Because of the existence of the carbon coating, the resistor can tolerate electricity without being damaged. The schematic construction of a carbon resistor is shown below.
As previously stated, resistance is exactly proportional to distance; the value of the resistor may also be manipulated by changing the length of the spiral carbon film. An epoxy coating is also supplied to protect the resistor. The terminal section, as indicated in the diagram, is made of metal, and the connecting leads, which are linked to the metallic ends, are made of copper.
When building an electric circuit for a certain purpose, the exact amount of resistance in the circuit board must be induced. It is accomplished by including the carbon resistor, which is a small component. These components are a small packet of resistance connected to the circuit to limit the flow of current by a specific amount.
The most common symbol for a resistor in most circuit designs is a zig-zag line with the value of its resistance represented by the Ohms. Fixed resistors typically have only one resistance value. Nonetheless, variable resistors can be supplied with an unlimited number of resistances ranging from zero to their maximum value.