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Colored stripes are used in radio electronics to determine the resistance of fixed resistors. Most electronic components, particularly resistors, are very small in size, making it difficult to print markings directly onto the housing. Therefore, in 1920, a standard was developed to identify the values ​​of electronic components by color coding them.

How to determine the resistance of a resistor by colored stripes

The figure below shows the location of the value bars, multiplier and tolerance for a fixed resistor. When marked with 6 colored stripes, an additional stripe indicates the temperature coefficient.

The gap between the multiplier and tolerance colored bars defines the left and right side of the resistor. Key points for determining resistor resistance by color stripes:

4 band resistor- has 3 color stripes on the left side and one color stripe on the right side. The first two bars on the left represent the resistance value, and the third is the multiplier. The bar on the far right determines the permissible deviation in percentage.

5 band resistor- has 4 color stripes on the left side and one color stripe on the right side. The first 3 colored bars determine the resistance value of the resistor, the fourth represents the multiplier, and the fifth bar is the permissible deviation from the nominal value in percent.

6 band resistor- has 4 color stripes on the left side and 2 color stripes on the right side. The first 3 color bars indicate the value of the resistor resistance itself, the 4th bar is a multiplier, the 5th percentage of deviation from the nominal resistance value and the 6th bar is a designation of the temperature coefficient of resistance, which increases the accuracy of the resistor resistance.

The temperature coefficient tells us about the behavior of the resistor in different temperature conditions operation.

Examples of determining resistor markings using colored stripes

Resistor marking with 4 colored stripes

Consider the color code of a resistor that has 4 color stripes: brown-black-red-gold. Brown corresponds to the value "1" in the color chart. Black represents "0", Red represents the multiplier "100". Thus, the resistance value will be:

10 * 100 = 1000 ohms or 1k ohms with 5% tolerance since the gold strip represents a +/- 5% tolerance. So the actual value of 1 kΩ could be between 950 Ω and 1050 Ω.

Resistor marking with 5 colored stripes

Consider the color code for a 5 strip resistor: yellow-purple-black-brown-gray. Yellow corresponds to value "4" in the color chart. Purple represents "7" and black represents "0". The brown bar determines the value of the “10” multiplier. Thus, the resistance value will be:

470 * 10 = 4700 ohms or 4.7 kohms with 0.05% deviation because grey colour deviation is +/- 0.05%.

Resistor marking with 6 colored stripes

In this case, the marking is similar to that of a resistor with 5 stripes, in addition there is only a sixth color stripe of the temperature coefficient, for example, this is a blue stripe.

The result is that the resistor has a resistance of 4.7 kOhm, with a tolerance of +/- 0.05% and a temperature coefficient of 10 ppm/K.

The main purpose resistors– converting current into voltage or performing the reverse process, limiting the current indicator, absorption electrical energy. Used in almost all complex electrical diagrams, so you should pay attention to the color coding.

Due to their small size, resistors are rarely marked with a numerical or letter value. Most often, colors are applied, which determine all the basic qualities. In order to choose the right resistor, you should know the features of applying colored dots or lines.

Standard color coding

In order to correctly mark and tables have become widely used, international standards have been adopted, according to which from 3 to 6 stripes can be applied to a resistor, each of which has a specific purpose.

Let's consider the features of standard color marking:

1. Marking with 3 stripes is carried out as follows: The first 2 rings indicate numbers, 3 – the multiplier. There is no 4 ring, since for all such resistors the accepted deviation is 20%.
2. 4 rings– marking, which is slightly different from the previous case. The last ring means deviation. All values ​​are selected using a special table. In this case, the deviation is 5%, 10%.
3. 5 rings means the minimum deviation rate, up to 0.005%. In this case, the first 3 rings represent numbers, which then need to be multiplied by a factor. You can find the multiplier using the same table; you need to look for the color value of 4 rings.
4. There are resistor options that have 6 rings. Their decoding is carried out in the same way as with 5 rings, only the last of them means the temperature coefficient of change. This value determines how much the resistance indicator changes when the temperature of the resistor body increases.

Not all tables have a column for decoding the 6th ring, which is worth considering.

What is it for?

Low power resistors are very small in size, their power is about 0.125 W. The diametric size of this version is about a millimeter, and the length is several millimeters.

Reading the parameters, which often have several numbers, is quite difficult, as is plotting them. When indicating the denomination, if the dimensions allow, a letter is often used to determine the fractional value of the value.

An example is 4K7, which means 4.7 kOhm. However, this method is also not applicable in some cases.

The color scheme of the marking has the following features:

1. Easy to read.
2. Easier to apply.
3. Can convey all the necessary information about denominations.
4. With time the information is not erased.

At the same time, we can note the main difference in this marking:

1. At 20% accuracy a marking containing 3 stripes is used.
2. If the accuracy is 10% or 5%, then 4 strips are applied.
3. More accurate options versions have 5 or 6 stripes.

To summarize, we can say that applying colors allows you to find out the accuracy and nominal values ​​of the resistor, for which you need to use special tables or online services.

Online calculators

The most popular include:

1. http://www.chipdip.ru/info/rescalc – a service that allows you to carry out calculations for design options that have 4 or 5 marking strips. The service works as follows: the table has columns that correspond to one color band or another, and rows contain colors. In order to carry out the calculation, it is enough to mark the color in the corresponding line. The calculator in question allows you to calculate resistance and tolerance, which are measured in megohms and percentages, respectively. The advantage of this online calculator is the presence of not only the name of the color, but also its sample. This feature allows you to quickly make comparisons to perform calculations. Unlike other similar calculators, in this case there is a visual picture that changes when you select certain colors. That is why it is very easy to use, since a clear example allows you to understand which resistor was chosen for the calculations.
2. http://www.radiant.su/rus/articles/?action=show&id=335 – a service that also allows you to quickly calculate the nominal values ​​for a version with 4 bands. This version of the calculator has simple diagram work: there are 5 fields, when opened, the name of the color and its sample are displayed. After selection, the resistance indicator is calculated, which is displayed in Ohms, as well as the maximum deviation in percentage. The service in question has not only a calculator, but also visual examples of calculations performed, tables with the necessary information, and much more.
3. http://www.qrz.ru/shareware/contribute/decoder.shtml - one of the few services that allows you to carry out calculations for 3 lines, as well as 4 and 5. Unlike other versions, this one does not have a visual picture of , what one or another version of the resistor looks like when the line color changes. We can also say that this version of the calculator is one of the most complex. If the resistor has 3 strips, enter the designations in fields 1, 2, 4, if 4 - in 1, 2, 4, 5, if 5 - you need to fill in all fields. The result is displayed as a resistance value in KOhm; there is also a field indicating the error as a percentage.

All calculations are carried out exclusively when marking is carried out in accordance with accepted rules GOST 175-72. Line reading is always done from left to right. It is worth noting that according to accepted rules, the first stripe is always located closer to the output.

If this cannot be done, the first stripe is made wider than the rest. These rules should be taken into account when deciphering the resistor using a calculator.

Universal color chart

There is a universal color table that allows you to quickly calculate the values ​​of each resistor if necessary.

When creating such a table, the following fields are selected:

1. The color of the ring or dot applied. In this case, both the name and an example are given.
2. Depending on, what a color is worth, it is possible to convert the color coding into a numerical value. This is necessary when creating a schema for symbol denominations.
3. Factor allows you to make a mathematical calculation of what resistance the considered design option has.
4. Also, for almost every color there is a field that indicates the maximum deviation from the nominal value.

It is worth remembering that each color can indicate a number in the marking, a multiplier value, or a maximum deviation.

Examples

Example 1:

Let us consider the use of such a table using the following example: brown, black, red, silver. We read the rings from left to right, the resulting value is always encoded in Ohms.

According to the data from the table, we carry out the following decoding:

1. Brown color in the first position denotes both a digit and a multiplier. In this case, the number will be “1” and the multiplier “10”. It is worth noting that the following colors cannot be used in the first position: black, gold or white.
2. Second color means the number of the second digit. Black means "0" and is not used in calculations. Having such data, we can conclude that the resistor has the alphanumeric marking 1K0.
3. Third color determines the multiplier. In our case, it is red, the multiplier of this color is “100”.
4. Last color means the maximum tolerance for deviation, and the silver color corresponds to 10%.

Using the table, we can say that the resistor in question is marked 1K0 and has a resistance value of 1000 Ohms (10*100) or 1 kOhm, as well as a tolerance of 10%.

Example 2:

One more complex example let's call the calculation of the nominal values ​​of the following resistor: red, blue, purple, green, brown, brown. This marking consists of 6 rings.

When decrypting, we note the following:

1. 1 ring, red– number “2”.
2. 2 ring, blue– number “6”.
3. 3 ring, purple– number “7”.
4. We select all numbers from the table. When they are combined, we get the number “267”.
5. 4 ring It has green color. In this case, we pay attention not to the numerical value, but to the multiplier. Green color corresponds to a multiplier of 10 5 . We carry out the calculation: 267 * 10 5 = 2.67 MOhm.
6. 5 ring It has Brown color and it corresponds to a maximum deviation in both directions of 1%.
7. 6 line brown, which corresponds to a temperature coefficient of 100 ppm/°C.

From the above example, we can say that deciphering the markings is not difficult, and the number of rings has virtually no effect on how complex the calculations will be. In this case, the resistor has a resistance of 2.67 MΩ with a deviation in both directions of 1% at a temperature coefficient of 100 ppm/°C.

The procedure can be simplified by using special calculators. However, not many people do the 6 ring calculation, which is worth considering.

The nominal series of resistors can be called the result of standardization of nominal values. Fixed resistors have 6 similar rows. Also, one row for variable denominations and a special row E3 have been introduced.

Using the example given denomination, let's decipher it:

1. Letter "E" means that marking is carried out according to a series of denominations. This beech is always included in the designation.
2. Numbers after letters means the number of nominal resistance values ​​in each decimal interval.

There are special tables displaying nominal series.

To identify standard series, GOST 2825-67 was adopted. At the same time, we can highlight several of the most popular standard series:

1. Row E6 has a deviation in both directions of 20%.
2. Row E 12 has a permissible deviation of 10%.
3. Series E24 has a maximum permissible deviation in both directions of 5%.

The subsequent rows E48 and E96, E192 have a deviation rate of 2%, 1%, 0.5%, respectively.

Summary table of resistor color coding

For everyday use, you can use a color-coded summary table that combines the following information:

1. Color matching certain values.
2. Numbers nominal series.
3. Magnitude multiplier
4. Magnitude admission.
5. Index temperature change coefficient.
6. Rejection rate.

Such a table will allow you to quickly decipher the markings.

Features of marking wirewound resistors

The rules adopted for the color marking of resistors apply to all types, including wire-wound versions.

In this case, there are only a few distinctive features things to consider:

1. 1 strip, which is wider than others and usually white, is not part of the marking, but only indicates the type of resistor.
2. Decimal exponents more than 4 cannot be used for marking.
3. Last strip may indicate special properties, for example, fire resistance.

The table used in this case is slightly different. The difference lies in the size of the multiplier.

Non-standard marking of imported resistors

Despite accepted rules color marking, some companies use their own standards. These include:

1. Philips is a manufacturer of consumer and industrial electronics that has introduced some of its standards in the field of resistor marking. Thus, it can be noted that the company uses colors not only to indicate the main characteristics, but also to display production technology and the properties of components. To do this, the body itself is painted a certain color, and the rings are arranged in a certain order relative to each other.
2. CGW and Panasonic also introduced their own labeling rules. This is how these manufacturers apply information about the special properties of the resistor.

Almost all manufacturers in the world have adopted established rules, which simplifies the procedure for identifying denominations.

In conclusion, we note that in addition to color markings, alphanumeric designations may be present. They are applied to the surface of fairly large resistor designs and can also be used to reveal performance characteristics.

First of all, let's deal with Soviet resistors.

No matter what you do, you cannot escape from Soviet electronics. Therefore, a little theory will not harm you.

At first glance, we must estimate what maximum power the resistor can dissipate. From top to bottom, below in the photo, resistors by power: 2 Watt, 1 Watt, 0.5 Watt, 0.25 Watt, 0.125 Watt. On resistors with a power of 1 and 2 Watts they write MLT-1 and MLT-2, respectively.

MLT is a type of the most common Soviet resistors, from abbreviated names M metal film, L lacquered, T heat resistant. For other resistors, the power can be estimated based on their dimensions. The larger the resistor, the more power it can dissipate into the surrounding space.

Units of measurement in MLTs - Ohms - are designated as R or E. Kilo-ohms - with the letter “K”, Mega-ohms with the letter “M”. Everything is simple here. For example, 33E (33 Ohms); 33R (33 Ohm); 47K (47 kOhm); 510K (510 kOhm); 1.0M (1 MOhm). There is also a trick that letters can precede numbers, for example, K47 means that the resistance is 470 Ohms, M56 - 560 Kilohms. And sometimes, in order not to bother with commas, they stupidly push a letter there, for example. 4K3 = 4.3 Kilohm, 1M2 – 1.2 Megaohm.

Let's look at our hero. Let's look immediately at the designation. 1K0 or in the words “one and zero”. This means that its resistance should be 1.0 Kilohm.

Let's see if this is really true?

Well, yes, everything agrees with a small error.

Color coding of resistors

To determine the resistance value of a color-coded resistor, you first need to rotate it so that its silver or gold stripes are on the right and a group of other strips are on the left. If you cannot find a silver or gold strip, then you need to rotate the resistor so that the group of strips is on the left side.

The color of the strip is a coded number:
Black – 0
Brown – 1
Red – 2
Orange – 3
Yellow – 4
Green – 5
Blue – 6
Purple – 7
Gray – 8
White – 9

The third bar has a different meaning: it indicates the number of zeros that should be added to the previous digital value obtained.

Stripe Color – Number of Zeros
Black – No zeros -
Brown – 1 – 0
Red – 2 – 00
Orange – 3 – 000
Yellow – 4 – 0000
Green – 5 – 00000
Blue – 6 – 000000
Purple – 7 – 0000000
Gray – 8 – 00000000
White – 9 – 000000000

It should be remembered that the color coding is quite consistent and logical, for example, green means either the value 5 (for the first two stripes) or 5 zeros (for the third strip).

The sequence of colors itself coincides with the sequence of colors in the rainbow (from red to purple colors) (!!!)

If a resistor has a group of four stripes instead of three, then the first three stripes are numbers, and the fourth strip indicates the number of zeros. The third digital strip makes it possible to indicate the resistance of the resistor with higher accuracy.

Let's look at a resistor unknown to us.

Basically, there are three, four, five and even six stripes on a resistor. The first strip is closest to the resistor terminal and is made wider than all other strips, but sometimes this rule is not followed. In order not to sift through reference books on the color marking of resistors, you can download many different programs on the Internet for determining the resistor value.

Very good online calculator you can also find .

Resistor marking calculator

I really liked the program. Even a preschooler can understand this program. Let's use it to determine the value of our resistor. We drive in the strips of the resistor we are interested in and the program will give us its value.

And at the bottom left in the frame we see the resistor value: 1kOhm -+5%. Convenient isn't it?

Now let's measure the resistance using a multimeter: 971 ohms. 5% of 1000 ohms is 50 ohms. This means that the resistor value must be in the range from 950 Ohms to 1050 Ohms, otherwise it can be considered unsuitable. As we can see, the value of 971 Ohms fits perfectly into the range from 950 to 1050 Ohms. Consequently, we have correctly determined the value of the resistor, and it can be safely used for our purposes.

Let's practice and determine the value of another resistor.

All OK;-).

Marking of SMD resistors

Digital marking of resistors

Let's look at the markings of resistors. Resistors of size 0402 (size values) are not marked. The rest are marked with three or four numbers, since they are a little larger and you can still put numbers or some kind of marking on them. Resistors with a tolerance of up to 10% are marked with three digits, where the first two digits indicate the value of this resistor, and the last third digit is 10 to the power of this last digit. Let's look at this resistor:

The resistance of the resistor shown in the photo is 22x10 2 = 2200 Ohms or 2.2 K.

Let's check if this is true? We take this tiny SMD component between the probes and measure the resistance.

Resistance 2.18 kOhm. A small error does not count.

SMD resistors with a tolerance of 1% and size 0805 and larger are marked with four numbers. For example, a resistor with the number 4422. This is calculated as 442x10 2 = 44200 Ohm = 44.2 kOhm.

There are also SMD resistors with almost zero resistance (there is still a very, very small resistance) or simply so-called jumpers. They look more aesthetically pleasing than any wires.

Coding resistors is the most common practice these days. Sometimes you come across resistors whose markings look very strange. Don't be alarmed, this is a simple code marking that is used by some manufacturers of electronic components. It might look something like this:

or even like this:

How to determine the resistance value of such resistors? For this purpose, there is a table with which you can easily determine the value of any resistor with a code marking. So, the first two digits contain the secret value of the resistor, and the letter is the multiplier.

Here is the actual table:

Letters: S=10 -2 ; R=10 -1 ; A=1; B= 10; C=10 2 ; D=10 3 ; E=10 4 ; F=10 5

This means that the resistance of this resistor is

we will have 140x10 4 = 1.4 MegaOhm.

And the resistance of this resistor

we will have 102x10 2 = 10.2 KiloOhm.

In the Resistor 2.2 program you can also easily find the code and digital marking resistors.

Choosing the BOURNS branding

Place the marker on “3 characters”. And we type our code marking. For example, the same resistor marked 15E. Below, on the left in the frame, we see the resistance value of this resistor: 1.4 Megaohms.