A resistor is considered one of the most commonly utilized components in electronics. This is a passive element of electrical circuits with a specific or variable value of electrical resistance. Resistors are designed to linearly convert current strength into voltage into current power, current limitation, and absorption of electrical energy. It is a widely used component in almost all electrical and electronic devices. Due to resistors, it is possible to limit and measure the current, divide the voltage, and create feedback loops.
Various types of resistors are used in electronics. The first is fixed resistors; their primary purpose is to limit the current flow amount (Federal Aviation Administration [FAA], 2018). Several properties, including resistance value, precision, and the capability to dissipate heat, are controlled by resistors (FAA, 2018). Moreover, it can be used in generating heat; for instance, as heat is perceived as undesirable energy loss, resistors can be applied in propeller anti-ice boots (FAA, 2018). One of the kinds of fixed resistors is carbon composition. It is a mixture of carbon particles, graphite, and ceramic dust combined with a binding substance (FAA, 2018). This composition is processed under high pressure and temperature. It is molded into the case; the wires are fixed (FAA, 2018). The thermal mass of the carbon resistor is higher to withstand high-energy pulses (FAA, 2018). The disadvantage of such registers is that they have low stability and increased noise.
Despite fixed resistors, there are also variable ones; their resistance value can be changed from zero to nominal.
To simplify the readability of the designation of the resistors, Color Code was introduced. Color coding eliminates the lack of readability; it also allows to determine the resistor’s value in any of its positions without resorting to turning it over or soldering it (FAA, 2018). Resistor color-coding uses a standard color gamut, each color of which is assigned its numerical unit (FAA, 2018). The resistor is usually marked by three or four bands. The first signifies the numerical resistance value (FAA, 2018). The second indicates the ohmic value; the third means the number of zeros added to the first and second bands’ digits (FAA, 2018). Thus, the colors cannot be the same as the resistor’s body to prevent confusion.
The second Kirchhoff’s and Ohm’s law means that when current flows across the resistor, the voltage drops, and its value equals the flowing current multiplied by the resistance value (FAA, 2018). Each electrical conductor has a specific internal structure (FAA, 2018). At the same time, current flow electrons collide with various inhomogeneities in the construction of a substance and lose energy, released in the form of heat (FAA, 2018). Protection of aircraft electrical systems is performed through the installation of some protective devices (FAA, 2018). These are circuit breakers, fuses, arc fault circuit breakers, and thermal protectors (FAA, 2018). Circuit protective devices are intended principally for the protection of the wiring. They also open the circuit, preventing the current flow when the latter becomes greater than the wires can reliably sustain.
To sum up, resistors are crucial elements in electrical engineering. Ohm’s law and active power are used for circuit design; reactive parameters are also considered, such as stay capacitance and inductance. There are multiple types of resistors; they relate to the group of passive elements resulting from its operation; the current can only decrease. Unlike active elements, passive ones by themselves cannot amplify the signal.
References
Federal Aviation Administration (FAA). (2018). Aviation Maintenance Technician Handbook-General: FAA-H-8083-30. Aviation Supplies & Academics, Incorporated.