A brief introduction of color ring resistance identification method
Color ring resistance identification method refers to the resistance above the use of four color rings or five color rings or six color rings to represent the resistance value. The color information representing the resistance value can be read from any Angle at once. Color ring marking is mainly used on cylindrical resistors, such as carbon film resistors, metal film resistors, metal oxide film resistors, fuse resistors, winding resistors.
Second, color ring resistance identification sequence
Color ring resistance is the most common type of resistance used in various electronic equipment. No matter how it is installed, the repairman can easily read its resistance value for easy detection and replacement. However, in practice, it is found that the sequence of some color ring resistors is not very clear, which is often easy to read wrong. In recognition, the following skills can be used to judge:
Technique 1: first find the color ring of the error mark, so as to arrange the color ring order. The most commonly used colors for resistance error are: gold, silver, and brown, especially gold and silver rings, which are rarely used as the first ring of resistance color ring, so as long as there are gold and silver rings on the resistance, you can basically identify this as the last ring of resistance color ring.
Technique 2: the identification of whether the brown ring is an error mark. Brown rings are often used as both error rings and significant number rings, and often appear in both the first and last rings, making it difficult to identify the first ring. In practice, it is possible to judge by the spacing between the color rings: for example, for the resistance of a five-channel color ring, the spacing between the fifth and fourth rings is wider than that between the first and second rings, thus determining the order of the color rings.
Tip 3: In the case that the color ring order cannot be determined only by the color ring spacing, the production sequence value of the resistance can also be used to distinguish. For example, there is a resistance color ring read sequence: brown, black, black, yellow, brown, its value is: 100×10000=1M ω error 1%, belongs to the normal resistance series value, if the reverse order read: brown, yellow, black, black, brown, its value is 140×1 ω =140 ω, error 1%. Obviously, the resistance value read in the latter order is not available in the production series of resistors, so the latter color ring order is not correct.
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Three, color ring resistance identification method
In the early days, color ring marking was used to indicate resistance values, tolerances and specifications of resistors when the surface of resistors was not sufficient for numerical representation. There are two main parts.
The first part: the group near the front of the resistor is used to indicate the resistance value.
The resistance value of two significant numbers is represented by the first three color rings, such as 39 ω, 39K ω, and 39M ω.
The resistance value of the three effective numbers is represented by the four color rings, such as 69.8 ω, 698 ω, and 69.8K ω. It is generally used for the expression of precision resistance.
Part two: A color ring near the rear end of the resistor is used to represent tolerance accuracy.
Each color ring in Part 1 is isometric, self-contained and easily distinguishable from the color ring in Part 2.
Tricolor ring resistor
The first color ring is the ten digit number, the second color ring is the digit number, and the third color ring represents the multiplier. Use the first three color rings to represent the resistance value, such as 39 ω, 39K ω, 39M ω.
Four color ring resistor
Four color ring resistance identification: the first and second ring respectively represent two effective number of resistance value; The third ring represents multiplication; The fourth ring represents the error.
Example:
Brown red gold
Its resistance value is 12×10^2=1.2 K ω error is ±5%
The error represents the resistance value, and the fluctuation of the standard value 1200 (5%×1200) indicates that the resistance is acceptable, that is, it is a good resistance between 1140-1260.
The first and second rings with four color rings represent the first two digits of resistance value respectively; The third ring represents multiplication; The fourth ring represents the error. The key to rapid identification is to determine the resistance value in a certain order of magnitude range according to the color of the third ring, such as a few K, or dozens of several K, and then "substitute" the number read by the first two rings, so that the number can be quickly read.
Five-color ring resistor
Identification of five color ring resistance: the first, second and third rings respectively represent the resistance value of three effective numbers; The fourth ring represents multiplication; The fifth ring represents the error. If the fifth color ring is black, it is generally used as a winding resistor, and if the fifth color ring is white, it is generally used as a fuse resistor. If the resistance body has only a black color ring in the middle, it means that the resistance is zero ohm resistance.
Example: red red black brown gold
Its resistance is 220×10^1=2.2K ω and the error is ±5%
The first color ring is hundreds, the second color ring is tens,
The third color ring is the digit number, the fourth color ring is the power of color times the color, and the fifth color ring is the error rate.
First, from the bottom of the resistor, find the color ring that represents tolerance accuracy, with gold representing 5% and silver representing 10%. In the above example, the end of the color ring is golden, so the error rate is 5%. Then from the other end of the resistance, find the first and second color rings and read their corresponding numbers. In the above example, the first three color rings are red, red and black, so their corresponding numbers are red 2, red 2 and black 0, and their effective number is 220. Read the fourth multiple color ring, brown 1. So, we get a resistance of 220 x 10^1=2.2K ω. That is, the resistance value between 2090-2310 is a good resistance. If the fourth multiple color ring is gold, multiply the significant number by 0.1. If the fourth multiple color ring is silver, multiply by 0.01.
Six color ring resistor
Six color ring resistance identification: six color ring resistance front five color ring and five color ring resistance is the same method, the sixth color ring represents the temperature coefficient of the resistance.
Key points of color ring resistance recognition
Take the four-color ring as an example:
(1) Memorize the number represented by each color of the first and second rings. Brown 1, red 2, orange 3, yellow 4, green 5, blue 6, purple 7, gray 8, white 9, black 0. Read it together and repeat it several times.
Keep in mind the order of magnitude represented by the color of the third ring, which is the key to fast recognition. Concrete is:
Gold: 0.1
Black: 1.
Brown: 10
Red: 100
Orange: 1000
Yellow: 10000
Green: 100000
Blue: 1000000
(2) In terms of order of magnitude, they can be roughly divided into three large classes, namely: gold, black, and brown are ohmic; Red, orange and yellow are in the kilo-scale; Green and blue are megohm. I'll divide it up just so you can remember it.
(3) When the second ring is black, the color of the third ring represents an integer, i.e., several, dozens, hundreds of K ω, etc., which is the special case of reading, so pay attention to it. For example, if the third ring is red, its resistance is the whole number of K ω.
(The third or fourth ring of a 4-ring resistance that represents a multiple is followed by several zeros, or if it is a negative number, the decimal point of the significant number is moved to the left.)
(4) Remember the error represented by the color of the fourth ring, namely: gold is 5%; Silver 10%; Colorless 20%.
For example
Example 1 When the four color rings are yellow, orange, red and gold, and the third ring is red and the resistance range is several K ω, the reading is 4.3 K ω according to the numbers "4" and "3" represented by yellow and orange respectively. The fourth ring is gold which means the error is 5%.
Example 2 When the four color rings are brown, black, orange and gold, the third ring is orange and the second ring is black, the resistance value should be tens of K ω, according to the number "1" represented by brown, the reading is 10K ω. The fourth ring is gold, with a margin of error of 5%.
In some cases, it is also possible to compare the two starting colors, because the first color of the calculation will not be gold, silver, or black. If these 3 colors are near the edge, you need to do the reverse calculation.
There are two ways to mark the color of the color ring resistor, one is to use the 4-color ring marking method, the other is to use the 5-color ring marking method. The difference between the two is that the first two digits of the 4-color ring represent the significant digits of the resistance, while the first three digits of the 5-color ring represent the significant digits of the resistance. The second-to-last digit of the 2-color ring represents the multiplier of the significant digits of the resistance, and the last digit represents the error of the resistance.
For 4-color ring resistance, its resistance value calculation method is as follows:
Resistance value = (number of first color ring *10+ number of second color ring) * the multiplier represented by number of third color ring
For the 5 color ring resistance, its resistance calculation method is as follows:
Resistance value = (number 1 color ring *100+ number 2 color ring *10+ number 3 color ring) * number of times represented by number 4 color ring