This article is about color coded resistor.
Color Coded Resistors
What is Resistor?
A resistor is a device which regulate or limit the flow of current in the electrical circuit.it is the important components of the electronic circuits. The resistor has two terminals which are connected by trace or wire to the electrical circuit. The resistance is measured in ohm (Ω), which Is the ratio of voltage across the resistor to the current. The higher the resistance of the resistor the lower the voltage will be.
Types of Resistors
There are different types of resistors which are used in different places for different purposes in electronic circuits. These resistors have different properties depending upon their construction. These resistors are available in different shapes, sizes, and made from different materials but normally resistors are classified into two types which are linear resistors and nonlinear resistors.
the other two types of resistors which is widely used in electronic circuits and many other applications is fixed resistors and variable resistors.
Fixed resistors:
Fixed resistors are those resistors which have fixed value that the value cannot be changed. It Is the most widely used resistors. These resistors are used in the electronic circuit.
the following are the application of fixed resistors.
Application of fixed resistor
- Fixed resistors are used in high frequency instruments.
- Fixed resistors are used in power control circuits.
- Fixed resistors are used in DC power supply.
- Fixed resistors are used in filter circuits.
- Fixed resistors are used in amplifiers.
- Fixed resistors are used in oscillation.
- Fixed resistors are used in telecommunication.
- Fixed resistors are used in electronic measurements equipment.
Variable resistor
Variable resistors are the resistors of which the value can be changed or can be adjusted either mechanically or electrically. It is an electromechanical transducer which works by sliding contact over the resistive elements. When variable resistor is used as a potential divider then is use three terminal and known as potentiometer while when use two terminals then known as variable resistor and called as rheostat. Electrically controlled variable resistors exist and are controlled electrically.
the following are the application of variable resistors.
Application of Variable Resistors
- Variable resistors are used to control volume in audio devices.
- It controls the brightness in the lighting system.
- It controls the speed of the fan in electronic devices.
- It is used in calibration of measuring equipment.
- It controls the speed of the motor.
- It controls temperature in the heating system.
- It is used to control frequency in electronic devices.
- Is used to control the contrast in displays
Linear resistor:
Linear resistors are those resistors whose value changes with the temperature and applied voltage. Most of the resistors are linear because when the current flows in it the voltage drops occur. Linear resistors are divided into two types which are fixed resistor and variable resistors.
the following are the application of Linear resistors.
Application of Linear Resistors
- Linear resistors are widely used in electronic circuits.
- It is used in voltage division, current limiting, signal attenuation.
- These resistors are applicable and very useful to ensure stability and performance of the circuit.
Nonlinear resistor:
In nonlinear resistor the electric current flowing in the resistor changes if the applied voltage change, changes come in temperature. There are different types of nonlinear resistors. Nonlinear resistance can be defined as the resistors which does not obey the ohm law these are the un ohmic devices and its I-V characteristics curve is nonlinear that as not a straight line.
the following are the application of non-linear resistors.
Application of Non-Linear resistors
- It is used in voltage regulation in power supplies.
- It is used to protect electronic devices from over voltage.
- It is used for current limiting in electronic circuits.
- It is used for surge suppression in electronic circuits.
- It is used in signal processing.
- It is used in voltage clamping.
Application of Resistors
Resistors are used for different purposes in electronic devices such as adjusting signal level, reducing current flow, dividing voltages, biasing active elements, terminating transmission line, etc. Resistors are used to create simple circuit e.g., voltage divider, pull up and pull-down resistors, RC filters and current limiter.
Color coded resistors
Band 1 | Band 2 | Band 3 | Band4 | Band 5 | Band 6 | |
Color | 1st | 2nd | 3rd | Multiplier | Tolerance | TCR (10-6/k) |
Black | 0 | 0 | ×100 | ±250 | ||
Brown | 1 | 1 | 1 | ×101 | ±1% | ±100 |
Red | 2 | 2 | 2 | ×102 | ±2% | ±50 |
Orang | 3 | 3 | 3 | ×103 | ±0.05% | ±15 |
Yellow | 4 | 4 | 4 | ×104 | ±0.02% | ±25 |
Green | 5 | 5 | 5 | ×105 | ±0.5% | ±20 |
Blue | 6 | 6 | 6 | ×106 | ±0.25% | ±10 |
Violet | 7 | 7 | 7 | ×107 | ±0.1% | ±5 |
Grey | 8 | 8 | 8 | ×108 | ±0.01% | ±1 |
White | 9 | 9 | 9 | ×109 | ||
Gold | ×10-1 | ±5% | ||||
Silver | ×10-2 | ±10% | ||||
Pink | ×10-3 |
This resistor calculator will help you to find the value, tolerance, and temperature coefficient of the color-coded resistor of any bands simply select the bands colors. It can calculate the maximum and minimum values which is based on tolerance ratio.
How to use it?
To use this calculator to find resistance value follow the following steps.
- Select the numbers of a bands on the resistor.
- Select the matching color in the table for each band.
- The resistance value will calculate along with minimum and maximum values.
Resistor color coding
Resistor color coding is a way to find the resistance, tolerance, and temperature coefficient of the resistor with low voltage rating due to its small size. Color band is a very easy method to find the resistance value and it is very cheaply printed on the resistor.
If the body of the resistor is large or large wattage resistor, then the resistance value, tolerance and wattage are printed on the body of resistor. E.g., surface mounted resistors (SMD) use alphanumeric codes printed on the body of the resistor.
This coding is defined in the international standard IEC. It describes the coding standard for both the resistor and capacitors.
Reading color coded resistors
In the case of the resistor there are 3 to 6 bands which indicate their resistance value, tolerance and sometimes it indicates the temperature coefficient of the resistance (TCR). The resistor bands are read from left to right. Sometimes the direction is not clear therefore the width of the tolerance is printed larger than the other bands about 1.5 to 2 times of the width of the others band. If gold and silver are present on the resistor body, it will always be on the right side. It is better to use a multiplier to get the exact resistance value.
In the case of the three-band resistor the first two bands represent the first two digits followed by one band for multiplier. There is no band for the tolerance so the tolerance will always be ±20%.
In the case of four band resistors, which are very commonly used resistors, the first band represents the first two significant digits. The third band represents the multiplier, and the fourth band represents tolerance.
In five band resistor the first three bands represent the significant digits, the fourth band represent the multiplier and the fifth band represent tolerance.
In the case of six bands resistor the first five bands have the same representation as a five-band resistor followed by one extra band that represents the TCR.
Tolerance of color coded resistors
Tolerance is the error percentage between the actual and the stated measured value. This error is due to manufacturing processes.
Calculating By color coded resistors
To calculate the resistance value, you need to group the significant digits value group. The value of the two or three bands depends upon the total number of bands. Then multiply the value to the multiplier to get the resistive value.
Let’s take an example of four band resistor!
For example, we have a resistor of four band the colors are follow.
Violet Green Yellow Gold
Because it is four band resistor the first two band represent the significant digits which is 75 according to the above table
Then multiply the number to the multiplier which is yellow in the third band and its value is ×104 =10000
The multiplication result is: 75 × 10000 = 750000Ω = 750kΩ
The fourth band indicate the tolerance which is gold, and its value is ±5%
Now
To calculate the minimum and maximum value of the resistance value, multiply the resistance value by the tolerance percentage.
Minimum = 750000 – (750000 × 5/100) = 750000-37500 = 712500 = 712.5kΩ
Maximum = 750000 + (750000 × 5/100) = 750000 + 37500 = 787500 = 787.5kΩ
Let’s take another example.
Suppose we have a resistor of four band.
The colors are followed.
Yellow, green, green, silver
Because it is four bands resistor the first two band represent the significant digit which is 45
The third band represent the multiplier which is ×105 = 100000
45 + 100000 = 4500000 = 450k ohm
Now to calculate the minimum and maximum value of the resistor, multiply the resistance value with the tolerance percentage.
Minimum value = 4500000 – (4500000 *10/100) = 4500000 – 450000 = 405000 =
405k ohm
Maximum value = 4500000 + (4500000 * 10/100) = 4950000 = 4950k ohm
Exceptions
A 0-ohm resistor is a resistor having one black band. Its resistor is zero and it is used to connect the two traces on a printed circuit board. It is also used in a PCB assembly.
Resistors which are used in the military include an additional band which indicates the failure rate.
Frequently Asked Questions FAQs
Q 1: what is resistor color code?
Ans: Resistor color code show the tolerance, resistance value and tolerance of the resistors.
Q 2: How to read the resistor color code?
Ans: hold the resistor and read from left to right and select the colors from the resistor bands. and select the tolerance from the 3rd or 4th band.