Resistor Colour Codes

Introduction

The resistor is a tiny electric body having printed with many colours on the body to denote the different values of electrical resistance. The colour band of the resistor is called resistor colour code. The electric designers print the rate of tolerance, resistance value as well as wattage rating on the body of a resistor in numerical or alphabetical form. This can be seen in a large power resistor. The number bands of the resistor body presented with the variation of three to six numbers. Among the three numbers, the first two numbers stand for the resistance value rate and the last colour band is denoted as a multiplier.

The identification process of Resistor Colour Codes

There are different types of resistors used in electric circuit construction. 3-Band Resistors comprises a lower resistance value and in this resistor, the colour of the three bands is brown, black as well as gold. The value of the resistor differs from 1.2 to 0.8 ohms. 4-Band Resistors is another type of resistor in which three bands are located on the left side and the other one is in the right side (Chowdhury & Kumar, 2020). In this type of resistor, the first two bands of colour defined the resistance value, the third colour band represents the rate of multipliers, and the last band of colour stands for the rate of electricity tolerance. The tolerance power of this resistor is below 20%.

Figure 1: Resistor Colour Codes

5-Band Resistors includes five different colour bands. Among them, the first three bands represent the digits of the resistance power. The last fourth band of colour denotes the rate of multiplier and the last colour band of the resistance signifies the rate of voltage tolerance (Chowdhury & Kumar, 2020).

This resistor denotes the temperature coefficient that generally indicates the reliability of the electric flow. The 6-Band Resistors is made with six different colour codes (Ashok, 2021). The first three bands represent the digits of the resistance power, the fourth colour band signifies the multiplication factor, the fifth colour band represents the rate of tolerance power and the last colour band stands for the temperature coefficient.

Resistor Colour Code calculator

Figure 2: Resistor Colour Code calculator

This chart describes the value and the rate of tolerance of different colours in the different types of resistance bands. The calculator of the resistor colour band is very helpful to identify the rate of tolerance, temperature coefficient as well as the resistance value of a colour by selecting the colour bands. The calculator also guides the calculation of the minimum and maximum value of the tolerance ratio (Morsin & Ali, 2021). In order to calculate the value of the colour just selects the colour from the colour band. The resistance value can also be calculated by measuring the minimum and maximum values from the table.

The formula of Resistor Colour Codes

In order to calculate the resistance power with the help of a colour code calculator, the knowledge of the value group plays an important role. In the resistor, the initial two or three numbers from the left side entirely depend on the total band numbers. Then the multiplier to get the exact resistance value of the resistors (JELTEN, SHUAIBU & DAJAB, 2021) should multiply the value. The initial two colours of the four-band resistor violet and green denote a significant digit that is 75, so the multiplication process will be 75 x 10000 = 750000 $\Omega$ and the least value will be 750 K.

Figure 3: Difference between Resistance colour code and Tolerance value

In order to calculate the minimum as well as the maximum value of resistance according to the resistor colour code calculator proceed with Minimum = 750000 - (750000 * 5/100) which is equivalent to 712.5k$\Omega$ (JELTEN, SHUAIBU & DAJAB, 2021). The calculation process of the maximum value is Maximum = 750000 + (750000 * 5/100) so the maximum value will be 787.5k $\Omega$.

Conclusion

According to the resistor colour code calculator, the tolerance of the colour band can be calculated with the formula Tolerance = Value of resistor × value of tolerance band. In the four-band resistor, the first two red bands represent the digit of the colour and the digital representation of these two colours is 2. The third colour band is black and the digital representation of this colour is 1. The final colour band of the resistor is gold and the digital representation of this colour is ±5%. All the values of the colour band can be presented in the numerical form of 22 Ω ±5 %.

FAQs

Q1. What is the working process of resistor colour code?

Ans. The resistor colour code is made with several colour bands that help to specify the rate of the resistance value, tolerance rate and the electrical resistance power. Sometimes reliability rate is also measured through this code. The high precision of registers has five different bands that denote five different aspects

Q2. What is the specification of the resistor colour code?

Ans. The colour code of the resistor helps to specify the different electrical perspectives of the colour band like the value of resistance and tolerance. The temperature coefficient is also calculated with this colour code.

Q3. By whom the resistor colour code was invented?

Ans. Radio Manufacturers Association invented the resistor colour code in the early 1920s. This colour code is very much applicable for calculating the value of resistance and tolerance.

Q4. What is the importance of resistor colour code?

Ans. The importance of the resistor colour code in the electrical device is very high. This colour code is applicable for measuring the resistance and tolerance value along with temperature coefficient according to the resistor colour code calculator.