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:
“Those who first introduced compulsory education into American life knew exactly why children should go to school and learn to read: to save their souls.... Consistent with this goal, the first book written and printed for children in America was titled Spiritual Milk for Boston Babes in either England, drawn from the Breasts of both Testaments for their Souls’ Nourishment.”
—Dorothy H. Cohen (20th century)
“Individually, museums are fine institutions, dedicated to the high values of preservation, education and truth; collectively, their growth in numbers points to the imaginative death of this country.”
—Robert Hewison (b. 1943)