If you are stepping in the world of Electronics, you need to have knowledge of reading components value through their codes. One such Coding is used in Resistor that is “color coding “.
This System was developed by Radio Manufacturers Association to Read the Value of resistance from the strip of colors printed on it. This system carries an advantage that if we are not having a multimeter or any kind of meter than we can still find the value of Resistance. As everything carries advantages and disadvantages in parallel, the problem with it is that when the component is overheated, it becomes difficult to read the value of Resistance. Although it is a minute issue which can be ignored.
The Resistors which we commonly use come with 4 colors printed on it. Although there are various kinds of Resistors which come with 5 or 6 colors printed on it. There is separate method to calculate the resistance for each type of resistor. I will be dealing with all of those Step by Step.
4 Band Colour Code Resistor
This is the Resistor with a band of 4 colors. For calculating the resistance of the resistor you need to look at the chart first and then follow the below-mentioned procedure:
- See the first color and write the digit corresponding to that color.
- Now, see the color second the color and write the digit corresponding to that color.
- These digits form a no and write that no aside.
- For the third color, write corresponding to it.
- Now multiply the no formed after the 3rd Step with digit formed after4th Step.
- Congrats! You have got the Resistance.
- The fourth color represents the tolerance value which means how much you resistor can go beyond or below the theoretical value.
Suppose the resistor has colors like Black-Brown-Red-Silver.
- Now Corresponding to Black: 0
- For Colour Brown: 1
- Digit Formed is: 10
- For red color, multiplier is 10^2 = 100
So theoretical value is: 10*100 = 1 000 ohms
And for tolerance of silver color, it is: 10%
Now the complete answer is: 1000 ± 10%
You might be wondering you have to carry the list of all values with you every time? But you can Remember this all by: "Black Brown Rodes Of Your Gate Became Very Good When Given Silver Colour".
5 Band Colour Code Resistor
You might not find 5 band resistors in daily use but they exist. These are used in the military or for high accuracy purposes. If you know how to find the resistance of the 4 band resistor then it is easy for you. For military purposes, the fifth band represents the component failure rate.
Let us consider the color code for the resistors with the bands ”YELLOW-VIOLET-BLACK-BROWN-GREY“. Yellow corresponds to the value ‘4’ in the color chart. Violet represents ‘7’ and Black represents the value ‘0’. Brown represents the multiplier ‘10’. Thus the value of the resistance to the corresponding color code is:
470*10 = 4700 ohms
Or 4.7 kilo ohm.
With the tolerance band being grey which represents a tolerance of +/- 0.05%.
6 Band Resistor Colour Coding
The 6 band resistors represent the change in their resistance with respect to temperature that is what we call temperature coefficient. We can consider the same color code used for the 5-band, with an additional temperature coefficient band with a blue color. This shows that the resistor has a value of 4.7 kilo-ohms, with tolerance +/- 0.05% and with a temperature coefficient of 10 ppm/K.