Resistance as one of the most important parameters of capacitors, we need to confirm its parameters. So, how do we confirm the parameters of a resistor?
Let's start learning the expression of resistor parameters below
[Resistor Direct Marking Method]
The direct marking method is mainly used for larger (high power) resistors, it will be the nominal resistance value and the allowable deviation of the direct digital label on the body of the resistor. For example, in a resistor marked 1kΩ, the allowable deviation of 10%, it is clear that this representation is very easy to identify.
Some of the larger power resistors are also marked on the rated power. For example, 100Ω ± 10% 5W, is indicated as a 100Ω resistor, the permissible deviation of ± 10%, the power rating of 5W.
Generally,larger resistors will use the Resistor Direct Marking Method to show its main parameters, but when the resistor is smaller, how do we confirm its size? Use a magnifying glass? Obviously, it would be more trouble. So when the resistor is small, we usually choose to use the colour coding method to confirm its resistance value.
[colour coding method]
Resistors in electronic circuits are mainly colour-coded, because the power of the resistors used is mostly 1/8W, 1/16W is very small and can only be colour-coded.
Figure 1
Figure (a) shows the 4 colour rings resistor colour ring position diagram, from the figure can be seen, these 4 colour rings indicate different meanings. The first and second respectively for the first and second effective number（Digit） of colour ring (effective number of two) the third for the Multiplier of the number of colour ring, the fourth for the allowable error level of colour ring.
Figure (b) shows the 5-bar colour ring resistor schematic, the 1st, 2nd and 3rd stripes respectively represent the 3-digit effective number（Digit）of colour rings (precision resistors with 3-digit effective number), the 4th strip is the multiplier colour ring, the 5th strip is Tolerance colour ring.
[Explanation of the meaning of resistor colour code]
The colours of the ring are used to indicate 0 to 9 in the colour code method.
Table 1 shows the specific meaning of the colour code in the colour code method (also applies to colour-coded capacitors, etc.).
|
Color |
Digit |
Multiplier |
Tolerance (%) |
|
|
|
Black |
0 |
100 |
|
|
|
Brown |
1 |
101 |
1 |
|
|
Red |
2 |
102 |
2 |
|
|
Orange |
3 |
103 |
|
|
|
Yellow |
4 |
104 |
|
|
|
Green |
5 |
105 |
0.5 |
|
|
Blue |
6 |
106 |
0.25 |
|
|
Violet |
7 |
107 |
0.1 |
|
|
Grey |
8 |
108 |
|
|
|
White |
9 |
109 |
|
|
|
Gold |
- |
10-1 |
5 |
|
|
Silver |
- |
10-2 |
10 |
|
|
Pink |
- |
10-3 |
20 |
Table 1
[Resistor colour ring identification method]
Regarding the identification of colour ring resistor parameters, the following points are stated.
(1) The colour code method uses the colour of the colour ring to indicate a specific colour or Multiplier, Tolerance, the whole colour code has 12 colours and one natural colour (the colour of the resistor itself).
(2) 4-bar colour ring resistors can be directly applied to the above table, and the 3rd effective digit of 5-bar colour ring resistors has the same specific meaning as the 1st or 2nd digit in the table.
(3) The unit of nominal resistance is Ω.
(4) When the Tolerance is ±20%, the colour ring indicating Tolerance is the resistor's original colour, and at this time, there are only 3 colour rings for the 4-colour resistor.
[Resistor Tolerance colour ring identification tips]
In a colour-coded resistor where the 4 colour rings are evenly spaced across the resistor, the trick to determine the order of the rings is.
According to the colour code table, the gold and silver colour code has no specific meaning in the Tolerance, but only indicates the specific deviation, so the gold or silver ring must be the last colour ring, according to which you can distinguish the order of each colour ring.
