Identifying Resistors:
The electronic color code is used to indicate the values or ratings of electronic components, usually for resistors, but also for capacitors, inductors, diodes and others. A separate code, the 25-pair color code, is used to identify wires in some telecommunications cables.
Most axial resistors use a pattern of colored stripes to indicate resistance. SMT ones follow a numerical pattern. Cases are usually brown, blue, or green, though other colors are occasionally found like dark red or dark gray.
Resistor Color Codeing:
Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White (Gold Silver).
Mnemonic phrases for remembering color codes of resistor:
There are many mnemonic phrases used to remember the order of the colors. They are, but are not limited to, and variations of:
- Bad Boys Ravish Our Young Girls But Violet Gives Willingly.
- Bad Beer Rots Our Young Guts, But Vodka Goes Well. Get Some Now!
- B.B. ROY of Great Britain had a Very Good Wife.
- Buffalo Bill Roamed Over Yellow Grass Because Vistas Grand Were God's Sanctuary.
- Bully Brown Ran Over a Yodeling Goat, Because Violet's Granny Was Gone Snorkeling.
- Buy Better Resistance Or Your Grid Bias May Go Wrong.
- Bill Brown Realized Only Yesterday Good Boys Value Good Work.
- Better Be Ready Or Your Great Big Plan Goes Wrong.
- Better Be Ready Or Your Great Big Venture Goes West.
- Black Bananas Really Offend Your Girlfriend But Violets Get Welcomed.
- Black Birds Run Over Your Biting Visible Gray Worms.
- Big Boys Race Our Young Girls But Violet Generally Wins.
- Black Boys Rape Our Young Girls Behind Victory Garden Walls.
- Black Boys Rape Our Young Girls But Virgins Go Without.
Explanation:
To remember the color bands on resistors in order of increasing magnitude.
- Numerically the value (0-9) of a resistor via the color-coded bands: Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (purple, 7), Gray (8), and White (9).
- Also, note that the red through violet are the colors of the rainbow (in order). Although the ROY G. BIV mnemonic for rainbow colors includes indigo between blue and violet.
Figure 1: A diagram of a resistor, with four color bands A, B, C, D from left to right. |
Figure 2: A diagram of a 2.7 Mega Ω color coded resistor. |
To distinguish left from right there is a gap between the C and D bands.
- Band A is the first significant figure of component value (left side)
B is the second significant figure (some precision resistors have a third significant figure, and thus five bands).Band CBand the decimal multiplieris - Band D if present, indicates
of value in percent (no band means 20%)tolerance
For example, a resistor with bands of yellow, violet, red, and gold has first digit 4, second digit 7 (violet), followed by 2 (red) zeros: 4,700 ohms. Gold signifies that the tolerance is ±5%, so the real resistance could lie anywhere between 4,465 and 4,935 ohms.
Figure 3: 4.7 Kilo Ω resistor with ±5% tolerance. |
All coded components have at least two value bands and a multiplier; other bands are optional.