Hobbies And Interests
Color Numeric Values
The resistor color code for numbers 0 to 9 is: black, 0; brown, 1; red, 2; orange, 3; yellow, 4; green, 5; blue, 6; violet, 7; gray, 8; and white, 9. These colors are also used to represent a power of 10 multiplier (the number of zeros that follow the numeric value). Black indicates no zeros, brown is one zero, red is two zeros, and so on. Resistors also have a tolerance value, silver representing plus or minus 10 percent and gold plus or minus 5 percent.
Reading 3- and 4-Band Resistors
For resistors that have three or four color bands, the fist two bands represent numeric values and the third is the multiplier -- that is the number of zeros that follow this value. For example, a resistor with three red bands indicates two, two and two zeros, or 2200 ohms (2.2K ohms). If there is no 4th band, the resistor's tolerance is plus or minus 20 percent. A 2.2K resistor's value could range anywhere from 1,760 to 2,640 ohms, since 440 ohms is 20 percent of 2.2K. A silver fourth band would indicate a range of plus or minus 10 percent, while a gold band is plus or minus 5 percent.
Other Bands
In special cases, some precision resistors (those that have a tolerance of only 1 or 2 percent) may have an additional band, in which case the first three bands will indicate the value and the fourth will be the multiplier. A manufacturer may include a sixth band to indicate some other factor, such as operating temperatures.
Which End To Start Reading From
When you look at a resistor, the color bands may be spread out and you might not know which end of the resistor to begin reading the color bands. Simply remember that the color code will never start with a silver or gold band.