To understand the amount of current (ohms) that a resistor can handle, you should be able to read the resistor color code. Every resistor has a color band wrapped around the center, which tells us the amount of current measured in ohms that the resistor can handle. Different color bands denote various current handling capacities of resistors. Therefore, understanding the color bands should help us to choose the right resistors. For example, a 100 Ohms resistor has a color band of brown, black, brown, and gold, in that order from left to right. And a 1k resistor color code has a color code comprising brown, black, red, and gold. Not all resistors have 4-band color codes, and you will find some resistors with 5-band color codes.
Decoding 1k resistor color code
Brown is the first color of a 4-band 1k ohm resistor color code followed by black, then brown again, and the last one is gold. Although resistors don’t have any polarity and are suitable for any type of orientation in a circuit, determining the resistor’s current handling capability is essential to choose the right one. This is why you must understand the significance of the colors in the resistors. At a glance, the order of the colors helps to understand the overall current handling capacity, while analyzing each color helps to understand the detailed properties of resistors.
In a typical 4-band resistor, the first two colors denote significant figures. The third color is the multiplier, and the final color represents the resistor’s tolerance which is the margin of allowable error. For example, Gold is the last color of the band, meaning the resistor has a tolerance of 5%. It is easy to spot the tolerance band printed on the resistor’s shoulder.
How to read a resistor color code?
To decode the color band of a 220-ohm resistor, follow the decoding instructions below:
Concerning a decoding chart, the first red band has a value of 2. So does the second red band, which also has a value of 2. Therefore, the first two red bands taken together are equivalent to 22. The third band of brown color is the multiplier which carries a value of 10 according to the decoding chart. Multiplying 22 by 10 gives us 220. The last band is gold which signifies that the resistor has a 5% tolerance of margin of error.
Why use 5-band resistors?
Five-band resistors have an additional band after the first three bands. For greater precision, 5-band resistors are the only choice. This type of resistor is essential in circuits sensitive to resistance, such as engineering and scientific instruments.
The method of decoding the 5-band color code follows a similar logic as the 4-band 1k resistor color code. The only difference is that the extra band denotes the sensitivity of the resistor. Simply said, 5-band resistors are more sensitive than 4-band resistors.
