DVD-164C Transcript
DVD-164C
Component Color Codes
Below is a copy of the narration for DVD-164C. The contents for
this script were developed by a review group of industry experts and
were based on the best available knowledge at the time of
development. The narration may be helpful for translation and
technical reference.
Copyright  IPC – Association Connecting Electronics Industries. All Rights Reserved.
Introduction
NARRATOR
You don’t have to be a great artist to appreciate the importance color plays in our lives. Color
has beauty, but it also has meaning. In electronics, we often use color to show the value of
certain components.
In this video, we’ll show you how to calculate the color codes on through hole axial resistors, as
well as through hole capacitors and inductors. To learn component number code calculation, see
the IPC program, DVD-165C. When you understand these techniques, you’ll be able to take the
mystery out of identifying the value and tolerance for these types of components. That way
you’ll always be sure that you have the correct component for the job.
Resistor Color Band Codes
The value of a resistor is expressed in a unit of electrical resistance called ohms. Axial resistors
will usually have 4 or 5 color bands that will be turned into numbers using a color chart. The
chart will assign a number to each color of a resistor band. By turning the colors into numbers,
we can calculate the resistor’s value.
Although resistors will typically have four or five bands… occasionally, there may be a sixth
band. If the resistor has four bands, the first three bands tell you the value and the fourth band
will be the tolerance. Tolerance is a measure of how close the component must be to its value.
For example, the tolerance of this100 ohm resistor is plus or minus 5 percent. 5 percent is
equivalent to point zero five. Point zero five times 100 equals five. One hundred plus five is
105…and 100 minus five equals 95. So our tolerance, or operating range is 95 to 105 ohms.
For a five band resistor, the first four bands define the value and the fifth band is the tolerance.
The way to tell which band is the tolerance is to look for the band that is slightly set apart from
the other three or four bands. The tolerance band may also be a little wider than the value bands.
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DVD-164C Transcript
Once you determine which band is first, we’ll use the color chart to calculate the value. The color
chart tells you the number for each color. As you can see, zero is black; one is brown; two is red;
three is orange; and so on.
Let’s calculate the value of this four band resistor. The first two bands are simply the first two
numbers of the resistor’s value. The first band is violet so it’s a 7 – and the second band is green,
which is a 5. Therefore, we have 75 for the first two numbers of the value. The third band is
called the multiplier. Unlike the first two bands, we don’t use the third color number as a
numerical value. Instead, we add that number of zeros to the first two numbers – in effect
multiplying the number. In our example, the third band is orange – so we add three zeros to the
75. That gives us 75,000. So the value of our resistor is 75,000 ohms.
The last band defines the tolerance. As you can see, there are fewer colors used for this band.
Brown, red, gold and silver are the most common. Other color tolerance bands include green,
blue, and violet. These additional colors apply to higher precision type components. In our
example, the fourth band is gold – so the tolerance for this resistor is plus or minus 5%.
Going back to the multiplier band, we explained that orange was a three – causing us to add three
zeros to make 75,000 ohms. To make this number less complicated, we can use the letter K to
replace the three zeros. K is an abbreviation for thousand – which has three zeros. Since there
are one thousand ohms in one kilo-ohm, or K… we can also identify the value of this resistor as
75K ohms.
Let’s look at another resistor and calculate the color bands. The first two bands are brown and
black – which gives us a one and a zero, or 10. Notice that the multiplier band is blue. Blue
indicates six zeros. The value of this resistor is 10 million ohms. 10 million contains a lot of
zeros. Capital “M” is the abbreviation for meg-ohms, or one million ohms – and can replace the
6 zeros. Therefore, we can also specify the value of this resistor as 10 meg-ohms. And don’t
mistake a lower case “m” for an uppercase “M”. They are two different measurements – use
uppercase “M” for meg-ohms, or million – and lower case “m” for milli-ohms, or hundred.
Finally, the fourth band is brown – so the tolerance for this resistor is 1%..
The multiplier band can be a little tricky. A black multiplier band means you don’t add any
zeros. In this example, the first band is green and the second band is white giving us a 5 and a 9,
or 59. Since the multiplier is black, no zeros are added – and the value of this resistor is 59 ohms
– with a tolerance of 5%. Also notice that a gold or silver multiplier band means you don’t add
any zeros – but you move the decimal point to the left – one place to the left for gold and two
places for silver. In this example, the value bands are 2 and 7. Since the multiplier is gold, the
decimal point is moved one place to the left – giving us a value of 2.7 ohms – plus or minus 2%.
Now, let’s take a look at five band resistors. Reading five band resistors is very similar to four
band resistors. The only difference is that the first three bands are all read as values. The fourth
band is the multiplier and the fifth band is the tolerance. In this example, the first three bands are
brown, orange and violet. Using the chart, we see that brown is one; orange is three; and violet is
seven – which gives us 137. The fourth band, or multiplier, is brown – which means that we add
one zero – for a value of 1,370 ohms. The tolerance band is also brown – so the tolerance is 1%.
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DVD-164C Transcript
Sometimes you’ll see a five band resistor with white as the last – or fifth band. Notice there is no
white tolerance band on the color chart. The white band is a military identifier – telling us that
component has military solderable leads. The white or fifth band will not be used for determining
the value or tolerance of the resistor. Instead, we read this type of resistor as a four band resistor
and ignore the fifth white band. In this case, we have a 500 ohm resistor with a 2% tolerance.
Next, let’s examine a six band resistor. Reading a six band resistor is the same as reading a five
band resistor – except that there’s a sixth band that defines the TC or TCR. TC stands for
Temperature Coefficient and TCR stands for Temperature Coefficient Resistance. TC or TCR is
a measurement of how much the resistance is modified by changes in temperature. Many
resistors change value as they heat up. TC or TCR is measured in units of parts per million, or
ppm per degree Celsius, or C. Based on how a resistor is made, resistance value may increase or
decrease depending on temperature.
Now, let’s take a look at a six band resistor. Again, the value and tolerance on six band resistors
are read the same as five band resistors. The first bands are the significant value bands. Using the
resistor color code chart, yellow is four, violet is seven and black is zero. At this point we have
470. The fourth band is the multiplier, telling us how many zeros to add. Brown is one, so we add
one zero. Our value is now four thousand seven hundred ohms. Moving the decimal three places
to the left will give us kilo-ohms – specifically, 4.7K ohms. The next band is the tolerance band.
Red is two so that gives us plus or minus 2%.
The sixth band is the Temperature Coefficient band. Looking at the chart we can see that
orange is 15ppm° C. Therefore, the value of this six band resistor is 4,700 ohms or 4.7K ohms
with a tolerance of 2% -- and a TCR of 15 parts per million per degree Celsius.
Now that you’ve been introduced to the method of reading resistor color bands, let’s do an
exercise to make sure you understand the process. We’ll start with this four band resistor. See if
you can determine the value and tolerance. Pause the program now and perform the calculation
using your color code chart – or use the optional Review Questions if provided.
The answer is 550 ohms, with a tolerance of 5%. The way we got that answer is the two value
bands are green – which gives us 55. The multiplier band is brown – which means we add one
zero, giving us a total of 550 ohms. Finally, the tolerance band is gold, or a 5% tolerance.
Let’s try another resistor. Use the color band chart to calculate the value and tolerance. The
answer is three thousand four hundred ohms, plus or minus 1%. We can also abbreviate this
value by converting it to 3.4K ohms. Remember, K represents one thousand. Let’s look at how
we made the calculation. The first value band is orange, or 3 – and the second value band is
yellow, or 4. That gives us 34. The multiplier band is red – which means we add two zeros.
That results in 3,400 ohms, or 3.4K ohms. The tolerance band is brown – which gives us a 1%
tolerance.
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DVD-164C Transcript
Next, let’s see how we do with a five band resistor. The answer is six million ohms, plus or
minus 0.5%. We can also abbreviate the value by converting it to 6 meg-ohms. Again, M is
short for one million. Let’s examine how we determined the answer. Our first color band is blue
– which gives us a 6. The next two value bands are black – giving us two zeros for a total of 600
for the three value bands of this five band resistor. The multiplier band is yellow – which means
we add four more zeros. That makes the total value six million ohms. Finally, the tolerance band
is green – which tells us the tolerance is plus or minus 0.5%.
Now, let’s try another type of five band resistor. The answer is 480 ohms, plus or minus 5%.
Remember that the white band is a military identifier, and the resistor should be read as having
four bands. Let’s see how we got this answer. The two value bands are yellow and gray – which
gives us 48. The multiplier band is brown – which means we add one zero – giving us a total of
480 ohms. And the tolerance band is gold – which is plus or minus 5% tolerance. Again, the
white band is a military identifier and is not used for determining the value or tolerance of the
resistor.
Let’s try a six band resistor. The answer is 263 ohms, with a 2% tolerance and a TCR of 100
parts per million per degree C. Again, let’s see how we got the answer. Remember, six bands are
the same as five bands – with the addition of the TCR band. The red, blue and orange bands are
value bands – which gives us 263. The black band is the multiplier – and since black is zero, no
zeros are added. That leaves us with 263 ohms. The tolerance band is red – specifying plus or
minus 2%. The sixth band is the TCR. As you can see, brown on the color chart equals 100 parts
per million per degree Celsius. Therefore, the value of this six band resistor is 263 ohms, plus or
minus 2% with a TCR of 100 parts per million per degree C.
Capacitor and Inductor Color Band Codes
When other types of components, such as capacitors and inductors, have color bands, they are
read in the same manner as resistors – with the bands representing number values, a multiplier
and tolerance. The only thing that changes is the unit of measure. Capacitors are measured in
Farads and inductors are measured in Henrys. Inductors and resistors both use the same color
codes for tolerance – but capacitors have twelve codes for tolerance.
We’ll start with capacitors. As we just mentioned, the value of a capacitor is expressed in a unit
of electrical capacitance called farads. The three most common units of measurement using
farads are microfarads, nanofarads and picofarads. The picofarad has the smallest capacitance
value. For example, one million picofarads is equal to one thousand nanofarads, or one
microfarad.
Let’s look at the color chart for a four band capacitor. As you can see, it is similar to the resistor
color chart. The first two value bands are identical. The multiplier band is slightly different with
violet added to indicate seven zeros and grey and white replacing gold and silver to indicate eight
and nine zeros, respectively. The big change is in the tolerance band – where we go from seven
tolerance designations for resistors to twelve for capacitors.
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DVD-164C Transcript
When capacitors have color bands, they will always be the four band variety. Let’s calculate this
four band capacitor. The first two bands are blue and violet – which gives us a six and a seven, or
67. Notice that the multiplier band is orange. Orange indicates three zeros. The value of this
capacitor is sixty seven thousand picofarads. All calculations for capacitor color bands will be in
picofarads. 67,000 picofarads can be converted to 67 nanofarads, or point zero six seven
microfarads. The fourth tolerance band is yellow – indicating a tolerance of 4%..
Let’s see if you can determine the value and tolerance of this capacitor. The answer is two
hundred thousand picofarads, plus or minus 5%. Let’s look at how we made the calculation. The
first value band is red, or two – and the second value band is black, or zero. That gives us 20.
The multiplier band is yellow – which means we add four zeros. That results in 200,000
picofarads. The tolerance band is green – which gives us a 5% tolerance.
Now, let’s turn our attention to inductors. Inductors are measured in henries and micro divisions
of henries. nH stands for nano-henry, micro H or uH stands for micro-henry – and mH
represents milli-henries. Axial inductors with color bands are always decoded in micro-henries.
Like capacitors, inductors typically have four color bands. Sometimes there will be a silver band
to the left of the first band. This silver band has wider spacing than the other bands and tells us
that this inductor was manufactured for the military. Let’s calculate this four band inductor. The
first two bands are both red – which gives us two 2s, or 22. Notice that the multiplier band is
orange. Orange indicates three zeros. The value of this inductor is twenty two thousand
microhenries. The fourth tolerance band is gold – indicating a tolerance of 5%.
Occasionally, inductors will only have three color bands. When this occurs, the first two bands
are value bands – and the third band is for tolerance. Notice that there is no multiplier band.
Let’s see how that works. In this example, the value bands are violet and white – giving us
seventy nine microhenries. The tolerance band is brown, or plus or minus one percent tolerance.
Now, let’s see if you can determine the value and tolerance of this four band inductor. The
answer is 700 microhenries, plus or minus 2%. Let’s see how we made the calculation. The first
value band is violet, or seven – and the second value band is black, or zero. That gives us 70.
The multiplier band is brown – which means we add one zero. That results in 700 microhenries.
The tolerance band is red – which gives us a 2% tolerance.
Some surface mount inductors also have color codes – indicated by three dots or stripes. With the
middle dot oriented at the top, the colors are read left to right. In this example, our surface mount
inductor has three dots – green, red and yellow. The first two dots represent the value numbers.
As you can see on the color chart, green is a five and red is a two. The third dot is yellow which
is the multiplier – giving us four zeros. Surface mount inductors are always calculated in
nanohenries – so our total value is 520,000 nanohenries. Since there is no color dot for
tolerance, tolerance is assumed to be plus or minus 20% -- which is the default percentage for any
inductor or capacitor where tolerance is not specified.
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DVD-164C Transcript
Substitutions
Our final topic involves component substitutions. There may be times when the component we
need to make a repair with is out of stock. If this is the case, it may be appropriate to substitute a
component with similar characteristics. Always refer to your company policy for substituting
components. Be aware that some companies never allow substitutions. When substituting
voltage, wattage or tolerance, check the Bill Of Materials for the complete description of the
component. It’s important to realize that exact matches are not always necessary. Here are some
general rules for substituting components.
Voltage can be substituted with a higher voltage but not lower. Voltage is the potential energy
that makes electricity flow in a circuit. For example, if the bill of materials calls for a 50 volt
component – a 100 volt component could be substituted in its place. If a 100 volt component was
substituted, that would be acceptable because the component can handle up to 100 volts. It
would be unacceptable if a 25 volt component were substituted instead. If 50 volts were applied
to a component rated for 25 volts, the component would not function properly and would likely
be damaged.
The same rule applies when substituting wattage. To substitute a resistor rated at one quarter
watt, you would need to use one that would be capable of receiving a higher wattage – say one
half watt – rather than lower, or one eighth watt.
Another substitution may involve tolerance. Unlike voltage and wattage that substitute using
higher numbers, when it comes to substituting tolerances, you must use a component of the same
value with a lower tolerance. The lower tolerance is a more controlled and precise component.
For example, the bill of materials description calls for a 5% tolerance. An acceptable substitution
is with a tolerance of 1%. One percent is considered a precision part. The operating range is
narrow and more controlled – so it is acceptable to use a 1% tolerance in place of the 5%.
This program has presented the details of how to accurately read component color bands. We’ve
also demonstrated how to calculate the value of resistors, capacitors and inductors.
There’s been a lot of information presented – and you certainly don’t need to remember it all.
What is important is to be able to use the methods shown in this video. That means using the
reference sheets we provide to help you to decipher the color codes. By learning and
understanding how to turn colors into numbers, you can take the mystery out of identifying the
value and tolerance for these types of components.
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