The color wheel is used to represent resistance value, tolerance and even temperature coefficient. If you can understand the meaning and calculation principle of various color rings, it is not difficult to identify the resistor color code. This simple chart makes it easy for you to grasp the color coding rules for resistors.

Resistors vary in resistance value, shape, and physical size. Virtually all leaded resistors rated up to one watt have specific color ring combinations that represent their resistance value, tolerance, and even temperature coefficient. A resistor may have three to six color rings throughout its body, with four color rings being the most common. The first few color circles represent the significant digits of the resistor value. Next is a magnification color wheel, which is used to move the position of the decimal point left or right. The last color circle represents the tolerance and temperature coefficient.

Let's start with the color code diagram below and start with some examples:

1. 3 or 4 ring resistor

The first two color circles represent the first two digits of the resistance value in ohms. On a 3-ring or 4-ring resistor, the third color band indicates the magnification. This magnification changes the position of the decimal places to represent any order of magnitude from megaohms to milliohms. The fourth color circle represents tolerance. Remember, if this color band is not present on a 3-ring resistor, the default tolerance is ±20%.

2. 5-ring or 6-ring resistor

High-precision resistors also have a color ring that represents the third significant digit. If your resistor has 5 or 6 color rings, then the third color ring is this color ring, combined with the first and second color rings to represent the number. Continuing to look to the right, the fourth color circle represents the magnification, and the fifth color circle represents the tolerance. 6-ring resistors are basically the same type as 5-ring resistors, with the extra color ring indicating reliability, or temperature coefficient (ppm/K) specifications. Taking brown, the most commonly used color in the sixth color wheel, as an example, a 10°C change in temperature will cause a 0.1% change in resistance value.

Frequently asked questions about resistor color codes:

How to tell which end to start reading information on a resistor?

• As with many resistors, some of the color rings are more closely spaced or concentrated at one end. Hold the resistor in your hand so that the clustered color rings are oriented to the left. Then read the resistor information from left to right.

• There is no way the leftmost side of the resistor is a metallic color wheel. If the color ring on one end of the resistor is gold or silver, then its resistor tolerance is 5% or 10%. Place this resistor so that the color circle is on the right, and again, read from left to right.

• Typical resistor values range from 0.1 ohm to 10 megohms. It can be concluded that the third color ring of a 4-ring resistor is always blue (106) or a lower numerical color, while the fourth color ring of a 5-ring resistor is always green (105) or a lower value color. Lower value color.

Why doesn't my high voltage resistor have a metallic color ring?

On high-voltage resistors, yellow and gray replace gold and silver to avoid metal particles in their surface coatings.

What is a zero ohm resistor?

Zero-ohm resistors are easy to identify with just a black color ring, which basically acts as a circuit connection to connect to the wiring on the printed circuit board. They are packaged in a similar way to resistors, so the automated equipment used to place resistors can also be used to place them on the circuit board. This design eliminates the need for additional equipment to install jumpers.

Is there a trick to remembering the order of colors in a chart?

While there are some methods on the Internet that can help you with a memristor color code chart, the results are mixed. Another color chart mnemonic is to think of black as nothing, or "0," and white as the combination of all colors, or the highest value, "9." In the middle of the color chart, you'll see the standard rainbow colors arranged in sequence to represent the numbers 2 to 7, which is where the ROY-G-BIV (red, orange, yellow, green, blue, indigo, violet) you learned about as a child comes in. It's useful, but the indigo color is missing. You just have to remember that brown between black and red represents "1" and gray between purple and white represents "8" and you're done!

What is the "reliability" color wheel?

4-ring resistors in military resistors often have an additional color band to indicate reliability, or failure rate (%) per 1000 operating hours. And this is rarely seen in commercial electronics.

The development history of resistors

Resistors are basic components in electrical circuits. After testing the conductivity of various materials and discovering the existence of electric current, early scientists gradually came up with the concept of resistance. Scientists have discovered that copper, gold, and aluminum are good conductors with very low resistance, while air, mica, and ceramics are considered resistors because they greatly restrict the flow of electricity. Although its resistive properties have long been known in the industry, reliable resistors as we know them today were never created. It wasn't until 1961 that Otis Boykin created the first cheap, reliable resistor that scientists could precisely control. The amount of current delivered to a component.

His breakthrough made resistors less susceptible to temperature extremes and oscillations, ultimately making their low-cost production possible. As the U.S. military, IBM and numerous consumer electronics manufacturers placed orders for Boykin's new resistors, they found their way into everything from home appliances and computers to guided missiles.

Resistors are ubiquitous in today's electronics. As passive devices, they consume but never provide energy. They have a wide range of uses in circuits, for example, to regulate the current input to an LED, or to control the total voltage conducted to active devices such as transistors. Resistors can be used to block transmission lines and prevent reflections, or they can also be used as pull-up or pull-down resistors in microcontroller GPIOs to enhance system stability. Combinations of resistors and capacitors can create the timing sources necessary for flashlights or electronic alarm circuits. A "daisy chain" of resistors in series acts as a voltage divider, which is useful for components that need to operate at a lower input voltage.

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