3 Band Resistor

[Octavis Uberstine]

Can anyone read the resistor that the arrow is pointing to? From what I know you can not have a gold band as a number and if I am reading it correctly it has a tolerance of 0 which does not seem right.

I'd go for example 3 in the picture above and also say 2 ohms with a 5% tolerance. The left most band I would ignore but if you have a meter lift one leg from the PCB and measure it but be sure to compensate from the probe resistance because it will be significant in the low ohms range.

The following are tools to calculate the ohm value and tolerance based on resistor color codes, the total resistance of a group of resistors in parallel or in series, and the resistance of a conductor based on size and conductivity.

An electronic color code is a code that is used to specify the ratings of certain electrical components, such as the resistance in Ohms of a resistor. Electronic color codes are also used to rate capacitors, inductors, diodes, and other electronic components, but are most typically used for resistors. Only resistors are addressed by this calculator.

The color coding for resistors is an international standard that is defined in IEC 60062. The resistor color code shown in the table below involves various colors that represent significant figures, multiplier, tolerance, reliability, and temperature coefficient. Which of these the color refers to is dependent on the position of the color band on the resistor. In a typical four-band resistor, there is a spacing between the third and the fourth band to indicate how the resistor should be read (from left to right, with the lone band after the spacing being the right-most band). In the explanation below, a four-band resistor (the one specifically shown below) will be used. Other possible resistor variations will be described after.

In a typical four-band resistor, the first and second bands represent significant figures. For this example, refer to the figure above with a green, red, blue, and gold band. Using the table provided below, the green band represents the number 5, and the red band is 2.

The third, blue band, is the multiplier. Using the table, the multiplier is thus 1,000,000. This multiplier is multiplied by the significant figures determined from the previous bands, in this case 52, resulting in a value of 52,000,000 Ω, or 52 MΩ.

The fourth band is not always present, but when it is, represents tolerance. This is a percentage by which the resistor value can vary. The gold band in this example indicates a tolerance of 5%, which can be represented by the letter J. This means that the value 52 MΩ can vary by up to 5% in either direction, so the value of the resistor is 49.4 MΩ - 54.6 MΩ.

Coded components have at least three bands: two significant figure bands and a multiplier, but there are other possible variations. For example, components that are made to military specifications are typically four-band resistors that may have a fifth band that indicates the reliability of the resistor in terms of failure rate percentage per 1000 hours of service. It is also possible to have a 5th band that is the temperature coefficient, which indicates the change in resistance of the component as a function of ambient temperature in terms of ppm/K.

More commonly, there are five-band resistors that are more precise due to a third significant figure band. This shifts the position of the multiplier and tolerance band into the 4th and 5th position as compared to a typical four-band resistor.

On the most precise of resistors, a 6th band may be present. The first three bands would be the significant figure bands, the 4th the multiplier, the 5th the tolerance, and the 6th could be either reliability or temperature coefficient. There are also other possible variations, but these are some of the more common configurations.

Resistors are circuit elements that impart electrical resistance. While circuits can be highly complicated, and there are many different ways in which resistors can be arranged in a circuit, resistors in complex circuits can typically be broken down and classified as being connected in series or in parallel.

Now, in your particular case, that difference is almost so subtle you can not see it. However if you look closely you can see that the tolerance band has a slight gap to the neck of the resistor comparted to the first digit.

However, the tolerances involved in "painting" the lines is not that well controlled, especially for cheap resistors from over-seas. As such, sometimes you have no option but to verify the resistance with an ohm-meter. If the resistors are a mixed bag of singles, that can be quite the chore. If they are still on the tape, not so much. Measure one and write the value on the tape.

First, all the colors are some shade of brown, and they don't have the proper offset so you don't know which side is which. But even if you try both values, and somehow can tell the colors, you might notice both options are still not what the multimeter says.

That explains why they're so cheap: on the kit I bought, they're all labeled wrong. They're pretty accurate and the values are indeed on the E series. But they're the mislabeled, both on the paper strip and on the color code.

Mind you, it's a lot easier to work back from a known measured value and figure out what the bands mean, than to start from an unknown resistor, figure out left to right, or right to left, is that smudge an extra band, is that dark orange or light brown?

Sorry for this basic question. I have a problem determining which way I should read band on the resistor below. I know it's left to right, but which side of it really is "left"? As far as I know, this board was assembled manually, so the orientation of the resistor on the PCB is basically random, or at best unreliable.

If you measured 1 Mohm it is about right. It's a 1 Mohm 5% special resistor. It is not clear why you think it is burned, as it looks just fine and measures accordingly, so there is no reason to believe it is burnt and there should be no reason to replace it.

So to know how to even begin decoding the colour codes, it must be understood that there are different ways of encoding them, so even if there are five colour bands, it does not mean that a generic five band colour scheme can be used, as there are exceptions like in this case.

So, as verified with multimeter measurements, it really is a 4-band resistor with an extra fifth band. It means from left to right, it has two value/mantissa bands, one multiplier/exponent band, one tolerance band, and the extra band.

The brown-black bands mean 10, green band means to multiply by 100k, gold band means 5% tolerance, and the extra green band means the resistor is of some special type which may be manufacturer specific.

So the problem is, if you don't know what the resistor does in a circuit or why it must have some special properties, don't simply change it to a standard resistor, because it might cause issues with the safety or operation of the device.

Here we have an example.
No matter if the blue or the black were the first line the bands would not enter correctly into the 5 band calculator. This resistor does work however in the 4-band calculator. Blue, Gray, Silver, Gold.
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One key indicator is to look for a gap in the bands. Most resistor companies will put a slightly larger gap between the multiplier and the tolerance gap then between the other bands. Here is an example from Yageo showing a 4 band resistor with a special band.
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Now that you have identified that you have a 4 band resistor with a 5th band you want to know what it is calling out. This can also be a bit tricky.
Per IEC 60062:2016 the standard color code would call out Temp Coefficient.

Trying to identify which you have can range from hard to impossible. If it is a color it is most likely a temp coefficient IEC 60062:2016. If your 5th band is black you are best to try to identify the resistor manufacturer and look at their data sheet.

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The online resistor calculator is a tool by Utmel Electronic used to calculate resistor values for 4 band, 5 band, and 6 band resistors, in the range of ohms, Kilo Ohms, and Mega Ohms typically. And this resistance calculator is developed to calculate the color code using the resistor color codes on their surface.Just select the right color corresponding to each column and you can get the Resistor value on the right of the calculator immediately.

Take a 4-band resistor as the example, 10k ohm resistor color code 4 band is: Brown-Black-Orange-Red. So the 1st band of Color: Brown, 2nd band: Black, Multiplier: Orange and Tolerance: Red. Thus, the output of resistor value is 10K ohms 2%. And the below picture shows you the 100 Ohm Resistor Color Code for 4-band resistors.

Resistors are usually used in electrical components with the aim of restricting the flow of electric current. They are usually tiny components with wire leads protruding from all sides. Resistors are special electronic components in circuits. It is made with the purpose of a precise quantity of electrical resistance.

The range of resistors may be from less than 1 Ohm (Ω) to over 20 mega Ohms (Ω) or 20 million Ohms (Ω). And there are two types of resistors: variable resistors and fixed resistors. A variable resistor can provide different values of resistance, however, the fixed resistor just has a single value. Meanwhile, there are 4 main classes of fixed resistors: carbon-composition resistors, Film resistors, wire wound resistors, and surface-mount resistors.

Generally, the carbon-composition resistors have 3 to 6 resistor color bands. And the below electrical color code resistor chart shows you the resistor strips of the 3 band type, 4 band type, 5 and 6 band type. Compared with a 4-band resistor, a 5-band type is more precise because of its third significant digit. And a 6-band resistor has the 6th band, which is a temperature coefficient band.

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