A Comprehensive Explanation to Resistor Color Code

A Comprehensive Explanation to Resistor Color Code

Resistors are a commonly used electronic component, but the public does not know much about them, especially the color codes on resistors, and non-professionals do not know how to interpret them. This article explains in detail what color codes mean and how to interpret them.

What Is The Resistor?

Resistors generally consist of three parts: resistor body, insulating skeleton and terminals. The resistor body plays a decisive role. Common materials include cement, films, metals, ceramics, semiconductors and other resistance wires. 

A resistor means to block, so it mainly plays a role in stabilizing and regulating voltage or current in a circuit, such as limiting current, dividing voltage or providing a specific voltage level, and converting electrical energy into heat energy, etc.

In some environments, using the characteristics of the resistor itself to collect the ambient temperature is also a function of the resistor. The unit of resistance value is ohms. In practical applications, resistors in series or parallel require attention to stray inductance and capacitance as well as noise.

Resistors are widely used in household appliances and electronic circuits such as push button switch led voltage application.. Its regulating circuit function is very stable, so it has a wide range of uses.

Classification of resistors

According to the volt-ampere characteristics, resistors are divided into linear resistors with constant resistance and nonlinear resistors with variable resistance.

Classification according to materials:

Wirewound resistors are made by winding alloy wires of copper, nickel and other metal materials around an insulating frame, and pouring or coating an insulating protective layer on the outside. They have high power loads and also protect the resistors from temperature effects. The resistance value can be determined based on the wound resistance wire.

figure 1 Wirewound resistors


Carbon film resistors are the earliest resistors used and are also the most common resistors. Spray a layer of carbon film on the porcelain rod and apply green epoxy resin protective paint, and cut it into a spiral pattern. The more spirals there are, the greater the resistance will be. The fewer the spirals, the lower the resistance. This is a high-temperature vacuum coating technology. Its function is equivalent to a high voltage resistor.

figure 2 Carbon film resistors


Metal film resistors use high-temperature vacuum to plate metal on the surface of a porcelain rod. They are highly accurate but more expensive than carbon film resistors. Therefore, they are often used in high-end audio, computers, defense electronics, and space equipment. Metal oxide film resistors are also one of them. Its surface is a layer of metal oxides such as tin oxide, and then sprayed with a layer of non-combustible material. 

figure 3 Metal film resistors

Special resistor:

The fuse resistor acts as a fuse and resistor, breaking the circuit when the power exceeds the rated power.

Sensitive resistors include photoresistors, humidity-sensitive resistors, varistors, force-sensitive resistors, etc., and there are many types. These resistors are very sensitive to external environmental conditions and physical characteristics. When the values of these physical properties change, the resistance value also changes. This is what we usually call a semiconductor resistor.

figure 4 Special resistor

In short, choosing the right resistor can maximize its effect and make your production more efficient.

How to read resistor color codes

Knowing what the various color codes on resistors mean can help you calculate their values faster and use them with the appropriate equipment.

The resistor has several bands of different colors, usually black, brown, red, orange, yellow, green, blue, purple, gray and other common colors. These different colors represent different numbers, and colors at different positions represent different meanings. The combination of different color bands represents different resistance values. By comparing the color codes, the resistance value and error rate can be calculated.

For example: for a four-band resistor, the values in the first and second bands represent the tens and ones values, the third band is the multiple, and the fourth band represents the error rate. First, find the color representing the error rate from the bottom end of the resistor, and then the other end is bands 1, 2, and 3. Examples are as follows:

figure 5 four-band resistor read resistor color codes

Precision resistors are represented by five bands. How to determine the color of the band represents the same meaning as the four bands. The fifth band is the error rate, and the fourth band is the multiple. If the band representing the multiple is gold, the decimal point moves one place to the left. If the band representing multiples is silver, the decimal point moves two places to the left.

figure 6 five-band resistor read resistor color codes

Each color represents a number and has different meanings in different positions. The resistance value can be calculated by matching the color of each band to the color code in the table.

figure 7 color code in the table

In short, the reading of resistor color can refer to the following formula: abc*d±e


Why should we remember the colors on resistors?

Memorizing these colors can quickly calculate the resistor value and which product it will fit into the circuit.

How else can resistors be classified?

Resistors can also be classified according to the number of bandss in their appearance. Common resistors include three-band, four-band, five-band, and six-band resistors.

What should I do if the resistor is faulty?

First observe whether there is any looseness, and then use a multimeter to test it.

Is there an easy way to remember what these colors mean?

There is a little formula: brown one, red two, orange are three, four yellow, five green and six are blue, seven purple, eight gray and nine are white, black is zero, gold five silver and ten represent errors. Remember this and you will get twice the result with half the effort at work.

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