There are two ways to indicate the resistance on a resistor: direct marking method and color ring method.
The direct marking method is to print the resistance value directly on the resistor with text. For example, 4.7 or 4R7 is printed on a 4.7Ω resistor, and 1.5k or 1k5 is printed on a 1.5kΩ resistor.
Color circle representation of resistance value
Color ring notation is to print several color rings of different colors on the resistor to indicate the resistance value and error. The unit of the resistance value is Ω.
The color wheel generally adopts 12 colors of black, brown, red, orange, yellow, green, blue, purple, gray, gold, and silver, and their meanings are shown in Table 1-2.
The color wheel on the resistor has 4 color wheels and 5 color wheels.
For a resistor with 4 color rings, the first and second color rings represent 2 significant digits, the third color ring represents the multiplier, and the fourth color ring represents the error, as shown in Figure 1-6. For example, if the four color rings of a resistor are "orange, blue, yellow, and silver" in sequence, the resistance value is 36×104=360kΩ, and the error is ±10%.
For a 5-channel resistor, the first, second, and third color rings represent 3 significant digits, the fourth color ring represents the multiplier, and the fifth color ring represents the error, as shown in Figure 1-7. For example, if the five color rings of a resistor are "green, brown, black, red, and gold" in sequence, its resistance value is 510×10=51kΩ, and the error is ±5%.