Prompt 1: First find the wrong color ring, so as to arrange the color ring order. The most commonly used colors to indicate the resistance error are: gold, silver and brown, especially gold rings and silver rings, which are rarely used as the first ring of the resistance color ring, so as long as there are gold rings and silver rings in the resistance, it can basically be regarded as the last ring of the color ring resistance.
Tip 2: Is the brown ring an error sign? Brownian rings are often used as error rings and effective digital rings at the same time, and often appear in the first ring and the last ring at the same time, making it difficult to identify who is the first ring. In practice, it can be judged according to the interval between the color rings: for example, for the resistance of a five-channel color ring, the interval between the fifth ring and the fourth ring is wider than the interval between the first ring and the second ring, and the arrangement order of the color rings can be judged accordingly.
Tip 3: If the color ring order cannot be judged only by the color ring spacing, it can also be judged by the production sequence value of the resistor. For example, the color ring reading sequence of a resistor is brown, black, black, yellow and brown, and its value is:100×104Ω =1mΩ, which belongs to the normal series resistance value. If read in reverse order, it is: brown, yellow and black 0%. Obviously, the resistance values read in the latter order are not available in the production series, so the latter color ring order is wrong. Resistors are generally divided into carbon film resistance, metal film resistance, cement resistance, line resistance and so on. Generally, there are many carbon film resistors for household appliances, because the cost is low. Metal film resistance has higher accuracy and is used in equipment with higher requirements. Cement resistance and wire-wound resistance can bear relatively large power, and the precision of wire-wound resistance is relatively high, so they are often used in measuring instruments with relatively high requirements.
The resistance of low power carbon film and metal film is generally expressed by color ring, which is also an important step for us to learn resistance. The unit of resistance is ohm. It will be explained in detail below.
Color ring resistance is divided into four-color ring and five-color ring. Let's start with the four-color ring. As the name implies, four colored rings are used to represent the resistance value. Each color represents a different number, as shown below:
Brown 1 red 2 orange 3 yellow 4 green 5 blue 6 purple 7 gray 8 white 9 black 0 gold and silver indicate errors.
The meaning of each color circle is as follows:
The first color ring: the first number of resistance;
The second color ring: the second digit of the resistor;
The third color circle: 10 power;
The fourth color circle: false representation.
For example: resistance color ring: brown, green, red, gold, first place:1; Second place: 5; Third place: the power of 10 is 2 (that is,100); The error is 5%; That is, the resistance value is:15×100 =1500ω =1.5ω =1.5k.
There is also a more accurate "five-color ring" resistor. The resistance value of the resistor is represented by five color rings, as follows:
The first color ring: the first number of resistance;
The second color ring: the second digit of the resistor;
The third color ring: the third digit of the resistor;
The fourth color circle: the power of resistance multiplier 10;
Article 5 Color circle: error (usually brown, error is 1%)
Some five-color ring resistors have colored rings on the metal caps at both ends, and the color ring far away from the relatively concentrated four-color ring represents the error, which is the fifth color ring. The metal cap corresponding to the other end is the first color ring, which is read from here when reading. The second and third color rings are the second height and the second height respectively, and the fourth color ring represents the power of 10. For example, the resistance level of a color ring is red (red). Another example is brown-black-black-red-brown, which means that the resistance value of the resistor is:100×102 ω =10000ω =1000ω. It can be seen that the resistance error of four-color ring is 5- 10%, and that of five-color ring is often 1%, which improves the accuracy.
For example, there is resistance: Huang Zihong orange-brown, the first three digits are: 472, and the fourth digit represents the cubic of 10, that is, 1000, and the resistance value is: 472× 1000 ohm =472Kiloohm (that is, 472 k).