How do you give values to resistor color codes?

Answer 1

Resistor Colour Bands Explained

We need to know the difference between some different types in order to read the colour codes of resistors.

Where as "most" resistors commonly in use, uses four bands, there are others using five and even six bands.

It is not always easy to know which way to hold the resistor in order to read the code correctly.

On four band resistors, there is normally a gap between the first three and the last fourth band.

______ 1 2 3 4 5 6 ______ Example of a 4 band resistor Note that band 1,2,3 and 5 makes up the 4 in use

In this example the first 2 bands reads out the value directly.

The third band is used to tell you the multiplication factor.

First band is Brown. This is 1.

Second band is Red. This is 2.

This makes the number 12. Now for the multiplication factor.

Third band is Brown again. This is multiplication factor 10. We multiply the number 12 by 10.

The value of this particular resistor is 12x10 equals 120 Ohm.

(We can also think about brown as 1... One extra zero added to the answer. 12+0=120)

The 5th band tells us how accurate this value is! (tolerance of the resistor)

Gold indicate 5% accuracy.

See the schematics further down for more tolerances.

______ 1 2 3 4 5 6 ______ Example of a 5 band resistor Note that band 1,2,3,4 and 5 makes up the 5 in use

In this example the first 3 bands read out the value directly.

The 4th band is used to tell you the multiplication factor.

First band is Brown. This is 1.

Second band is Red. This is 2.

Third band is Black. This is 0.

This makes the number 120. Now for the multiplication factor.

4th band is Brown. This is multiplication factor 10. We multiply the number 120 by 10.

The value of this particular resistor is 120x10 equals 1200 Ohm.

(We can also think about brown as 1... One extra zero added to the answer. 120+0=1200)

The 5th band tells us how accurate this value is! (tolerance of the resistor)

See the schematics further down for these tolerances.

______ 1 2 3 4 5 6 ______ Example of a 6 band resistor Note that all bands 1 through 6 is in use

Brown, Red, Black; makes 120; multiply by brown (10) and you get 1200 Ohm.

5th band is Gold (1200 Ohm +-5% tolerance)

The value of the resistor so far follows the previous 5 band explanation

The 6th band only adds more information about the resistor.

This information is related to temperature (Temperature coefficient).

In other words, how much the value will increase or decrease depending on temperature.

(most resistors will have slightly increased resistance with increased temperature.)

Now that you know how to read the different bands on different resistors

it is time for the full chart of colours used on resistors.

Colour value MultiplierTolerance Temperature CoefficientSilver 0,01 Silver 10% Gold 0,1 Gold 5% Black 0 1 Brown 1 10 1% 100ppm Red 2 100 2% 50ppm Orange 3 1k 15ppm Yellow 4 10k 25ppm Green 5 100k 0,50% Blue 6 1M 0,25% Violet 7 10M 0,10% Gray 8 0,05% White 9

Note:

Some resistors may lack the band for tolerance alltogether. These resistors may be highly inaccurate and offers only 20% accuracy regarding their markings.

Note that the temperature coefficient is different for different values of resistors.

We calculate the temperature drift by dividing the resistor value by 1 million (That gives us 1 part of a million), then we multiply by the 6th band code value of which can be 15,25,50 or 100.

This gives us the drift in Ohm per degree Celsius.

Example 1:

A resistor of 10.000 Ohm (10KOhm) with a 6th ring being Red, we calculate the drift:

10.000/1.000.000*red (50) = 0,5.

The resistance will increase by 0,5 Ohm per degree Celsius.

If the temperature increases by 45 degree Celsius, the resistance will increase by 22,5 Ohm.

Example 2:

A resistor of 1.200 Ohm (1,2KOhm) with a 6th ring being Brown, we calculate the drift:

1.200/1.000.000*brown (100) = 0,12.

The resistance will increase by 0,12 Ohm per degree Celsius.

If the temperature increases by 45 degree Celsius, the resistance will increase by 5,4 Ohm.

This drift is normally added because resistance increase with temperature.

If you plan on making equipment that is used in colder environments like in outer space, then you subtract this drift.

It depends on where you are and where you want to go.

Note that ALL resistors have a temperature coefficient whether this is marked or not.

Resistors that are not marked with a 6th band for this, typically have a TC of 200ppm or more.

Resistors do not necessarily follow the pattern 100% through temperature changes.

A resistor of 10.000 Ohm may increase its value from 0-50oC and then decrease again from 50-100oC. It may even be the other way around, or even a completely different pattern.

A 6 band resistor will typically only increase in value from 0oC and upwards. 6 band resistors are very high quality resistors that are designed to be predictable.

Some information not written on the resistors:

Commercial grade: 0oC to 70oC

Industrial grade: -40oC to 85oC (sometimes -25oC to 85oC)

Military grade: -55oC to 125oC (sometimes -65oC to 275oC)

Standard Grade -5oC to 60oC

The Electronic Industries Association (EIA), and other authorities, specify standard values for resistors, sometimes referred to as the "preferred value" system, where the colour coding is the key to understanding all of them. The above explanation deals with them all.

(It should be noted that allthough EIA have specified standard values, this is only a common guideline. The colour coding can easily describe other values depending on spechial needs.)

Further information on the standard series might be of interest and is as follows:

E6 series 20% tolerance. 6 values between 100 and 1000 Ohm.

The two first bands are used for the value. The third band is used for the multiplier.

Fourth band is most often omitted on these, hence indicating only +/- 20% accuracy.

The standard values are:

100, 150, 220, 330, 470, 680 Ohm.

E12 10% tolerance. 12 values between 100 and 1000 Ohm.

The two first bands are used for the value. the third band is used for the multiplier.

Fourth band is normally Silver, which indicate +/- 10% accuracy, or Gold, which indicate +/- 5% accuracy.

The standard values are:

100, 120, 150, 180, 220, 270, 330, 390, 470, 560, 680, 820 Ohm.

E24 5% tolerance (and often 2% tolerance). 24 values between 100 and 1000 Ohm.

The two first bands are used for the value. the third band is used for the multiplier.

Fourth band is normally Gold, which indicate +/- 5% accuracy, or Red, which indicate +/- 2% accuracy.

The standard values are:

100, 110, 120, 130, 150, 160, 180, 200, 220, 240, 270, 300, 330, 360, 390, 430, 470, 510, 560, 620, 680, 750, 820, 910 Ohm.

E48 2% tolerance. 48 values between 100 and 1000 Ohm.

The three first bands are used for the value. the fourth band is used for the multiplier.

Fifth band is normally Red, which indicate +/- 2% accuracy, or Brown, which indicate +/- 1% accuracy.

These resistors may have a 6th band indicating temperature coefficient. Often Brown (100ppm) or Red (50ppm).

The standard values are:

100, 105, 110, 115, 121, 127, 133, 140, 147, 154, 162, 169, 178, 187, 196, 205, 215, 226, 237, 249, 261, 274, 287, 301, 316, 332, 348, 365, 383, 402, 422, 442, 464, 487, 511, 536, 562, 590, 619, 649, 681, 715, 750, 787, 825, 866, 909, 953

E96 1% tolerance. 96 values between 100 and 1000 Ohm.

The three first bands are used for the value. the fourth band is used for the multiplier.

Fifth band is normally Brown, which indicate +/- 1% accuracy. Green (0.5%), Blue (0.25%), Violet (0.1%) or Gray (0.05%) might be found.

These resistors often have a 6th band indicating temperature coefficient. Often Brown (100ppm), Red (50ppm), Orange (15ppm), Yellow(25ppm).

The standard values are:

100, 102, 105, 107, 110, 113, 115, 118, 120, 124, 127, 130, 133, 137, 140, 143, 150, 150, 154, 158, 162, 165, 169, 174, 180, 182, 187, 191, 196, 200, 205, 210, 220, 221, 226, 232, 237, 243, 249, 255, 267, 270, 274, 280, 287, 294, 301, 309, 324, 330, 332, 340, 348, 357, 365, 374, 390, 392, 402, 412, 422, 432, 442, 453, 470, 475, 487, 499, 511, 523, 536, 549, 560, 576, 590, 604, 619, 634, 649, 665, 680, 698, 715, 732, 750, 768, 787, 806, 820, 845, 866, 887, 909, 931, 953, 976 Ohm.

E192 0.5, 0.25, 0.1% and even higher tolerances.

The three first bands are used for the value. the fourth band is used for the multiplier.

Fifth band is normally Green, which indicate +/- 0.5% accuracy. Blue (0.25%), Violet (0.1%) or Gray (0.05%) might be found.

These resistors often have a 6th band indicating temperature coefficient. Often Brown (100ppm), Red (50ppm), Orange (15ppm), Yellow(25ppm).

The standard values are:

100, 101, 102, 104, 105, 106, 107, 109, 110, 111, 113, 114, 115, 117, 118, 120, 120, 123, 124, 126, 127, 129, 130, 132, 130, 135, 137, 138, 140, 142, 143, 145, 150, 149, 150, 152, 154, 156, 158, 160, 160, 164, 165, 167, 169, 172, 174, 176, 180, 180, 182, 184, 187, 189, 191, 193, 200, 198, 200, 203, 205, 208, 210, 213, 220, 218, 221, 223, 226, 229, 232, 234, 240, 240, 243, 246, 249, 252, 255, 258, 270, 264, 267, 271, 274, 277, 280, 284, 300, 291, 294, 298, 301, 305, 309, 312, 330, 320, 324, 328, 332, 336, 340, 344, 360, 352, 357, 361, 365, 370, 374, 379, 390, 388, 392, 397, 402, 407, 412, 417, 430, 427, 432, 437, 442, 448, 453, 459, 470, 470, 475, 481, 487, 493, 499, 505, 510, 517, 523, 530, 536, 542, 549, 556, 560, 569, 576, 583, 590, 597, 604, 612, 620, 626, 634, 642, 649, 657, 665, 673, 680, 690, 698, 706, 715, 723, 732, 741, 750, 759, 768, 777, 787, 796, 806, 816, 820, 835, 845, 856, 866, 876, 887, 898, 910, 920, 931, 942, 953, 965, 976, 988 Ohm.

Each ascending series provide increased tolerance and accuracy. Where as we in the "old" days used variable resistors to adjust circuitry, we can today mass-produce electronics with fewer, more accurate components, hence mostly eliminating the need of variable resistors for adjusting and tuning.

Here is a mnemonic device for remembering the band colors in order by multiplier value. It may seem a little racist, but no disrespect is intended; the use of the word "black" in reference to a black color band prevents it from being confused with blue or brown. This mnemonic device is so effective that I recalled it from memory even though I haven't read a resistor in over 15 years.

"Black boys rape our young girls, but Violet gives willingly."

Black --> Black

Boys --> Brown

Rape --> Red

Our --> Orange

Young --> Yellow

Girls --> Green

But --> Blue

Violet --> Violet

Gives --> Gray

Willingly --> White

-HW

Answer 2

by the sentence

B- 0 - black

B- 1 - brown

R- 2 - red

O- 3 - orange

Y- 4 - yellow

of

Great- 5 - green

Britian- 6 - blue

has a

Very- 7 - violet

Greatwife- 8 - grey