DVD-164C Component Color Codes - IPC Training Home Page

DVD-164C TranscriptOnce you determine which band is first, we’ll use the color chart to calculate the value. The colorchart 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 twonumbers 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 iscalled the multiplier. Unlike the first two bands, we don’t use the third color number as anumerical value. Instead, we add that number of zeros to the first two numbers – in effectmultiplying the number. In our example, the third band is orange – so we add three zeros to the75. 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 ourexample, 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 threezeros to make 75,000 ohms. To make this number less complicated, we can use the letter K toreplace the three zeros. K is an abbreviation for thousand – which has three zeros. Since thereare one thousand ohms in one kilo-ohm, or K… we can also identify the value of this resistor as75K ohms.Let’s look at another resistor and calculate the color bands. The first two bands are brown andblack – which gives us a one and a zero, or 10. Notice that the multiplier band is blue. Blueindicates six zeros. The value of this resistor is 10 million ohms. 10 million contains a lot ofzeros. Capital “M” is the abbreviation for meg-ohms, or one million ohms – and can replace the6 zeros. Therefore, we can also specify the value of this resistor as 10 meg-ohms. And don’tmistake a lower case “m” for an uppercase “M”. They are two different measurements – useuppercase “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 anyzeros. 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 addany zeros – but you move the decimal point to the left – one place to the left for gold and twoplaces for silver. In this example, the value bands are 2 and 7. Since the multiplier is gold, thedecimal 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 fourband resistors. The only difference is that the first three bands are all read as values. The fourthband is the multiplier and the fifth band is the tolerance. In this example, the first three bands arebrown, orange and violet. Using the chart, we see that brown is one; orange is three; and violet isseven – which gives us 137. The fourth band, or multiplier, is brown – which means that we addone zero – for a value of 1,370 ohms. The tolerance band is also brown – so the tolerance is 1%.2