Printed Numbers
Color-coding of this form is becoming rarer. In newer equipment, most passive components come in surface mount packages. Many of these packages are unlabeled, and those that are labeled normally use alphanumeric codes, not colors.
In one popular marking method, the manufacturer prints 3 digits on components: 2 value digits followed by the power of ten multiplier. Thus the value of a resistor marked 472 is 4,700 Ω, a capacitor marked 104 is 100 nF (10x104 pF), and an inductor marked 475 is 4.7 H (4,700,000 µH). This can be confusing; a resistor marked 270 might seem to be a 270 Ω unit, when the value is actually 27 Ω (27×100). A similar method is used to code precision surface mount resistors by using a 4-digit code which has 3 significant figures and a power of ten multiplier. Using the same example as above, 4701 would represent a 470x101=4700 Ω, 1% resistor. Another way is to use the "kilo-" or "mega-" prefixes in place of the decimal point:
- 1K2 = 1.2 kΩ = 1,200 Ω
- M47 = 0.47 MΩ = 470,000 Ω
- 68R = 68 Ω
For some 1% resistors, a three-digit alphanumeric code is used, which is not obviously related to the value but can be derived from a table of 1% values. For instance, a resistor marked 68C is 499(68) × 100(C) = 49,900 Ω. In this case the value 499 is the 68th entry of the E96 series of preferred 1% values. The multiplier letters are as follows:
| Letter | Multiplier | Decimal |
|---|---|---|
| Z | 10-3 | 0.001 |
| Y or R | 10-2 | 0.01 |
| X or S | 10-1 | 0.1 |
| A | 100 | 1 |
| B or H | 101 | 10 |
| C | 102 | 100 |
| D | 103 | 1000 |
| E | 104 | 10000 |
| F | 105 | 100000 |
Read more about this topic: Electronic Color Code
Famous quotes containing the words printed and/or numbers:
“All that are printed and bound are not books; they do not necessarily belong to letters, but are oftener to be ranked with the other luxuries and appendages of civilized life. Base wares are palmed off under a thousand disguises.”
—Henry David Thoreau (1817–1862)
“Our religion vulgarly stands on numbers of believers. Whenever the appeal is made—no matter how indirectly—to numbers, proclamation is then and there made, that religion is not. He that finds God a sweet, enveloping presence, who shall dare to come in?”
—Ralph Waldo Emerson (1803–1882)