carbon film resistor color code

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Carbon film resistors

Finding unknown values

The inductor

The Transformer

Making circuit boards

Introduction

There are many resistors in the electrical industry and not all are as obvious as well all would like and finding there value is as mysterious to many of us when we first learn electronics as how many atoms are in the universe.
The resistor as we know it comes in three different flavors all of which can be interchanged to perform certain tasks. For example, the resistor above is great for low to moderate resistance but when you need to have a resistor that can change values the variable resistor is used. Below we will talk about all three different resistors, what they look like, how they work, what situations they are suited fore.

Carbon film resistor

   This is the most common type of resistor in the electronics field due to its wide range of resistive values and its standard looks have given it and easy to find image that has been the standard since the early 50's.
   The carbon film resistor comes in many widths, the larger the resistor is, the more watts it can withstand without heating up and blowing out. One good rule of thumb is to go by the illustration to the left, where the resistor size of the resistor is on the right side the rating at which the resistor can operate is to the left of each resistor in watts.
   Also when you are decoding the color code you will need to know where band one is, some clues are that the first band can never be gold. Also notice the distance of the gold band to from the end of the resistor compared to the ring on the other side. The number one band is almost always closest to the edge of the resistor.

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Quick overview on the color codes

COLOR	1^ST	2^ND	Multiplier	Tolerance
BALCK	0	0	1
BROWN	1	1	10	±1%
RED	2	2	100	±2%
ORANGE	3	3	1,000	±0.05%
YELLOW	4	4	10,000
GREEN	5	5	100,000	±0.5
BLUE	6	6	1,000,000	±0.25
PURPLE	7	7	10,000,000	±0.1
GREY	8	8
WHITE	9	9
SILVER			0.01	±10%
GOLD			0.1	±5%
NONE				±20%

   Lets take the larger resistor in the picture above since we can get a good look at it. To find the level or resistance that the resistor was designed to create, let us walk through the steps.

Step 1)
   Take the first band and compare its color to the chart, column 2 is for band one, column 3 is for band 2, and so on. Remember the first band is the one closest to the edge of the resistor while the first band can never be gold or silver.

Step2)
   Apply the second band to the chart and the result is placed next to your original answer but not added. For example, if our first digit was 1 and our second digit was a 0 then our total so fat is 10.

Step3)
   The third band is the multiplier, in out top resistor out third band is red, so our multiplier is 1000. So our total is
10 * 100 = 1,000 or 1k ohm.

Step 4)
   The fourth band or the tolerance band determines what range in percent that the it to work within, if the resistor is out of this range then it is considered to be a defect or a bad resistor.
   For example, our forth band is gold so out acceptance range is -5% to + 5% of out total value or 1050 ohms to 1950 ohms would be acceptable.

   This is however a low level of ohms when compared to other resistors but when you look at the resistor chart above you will see that this component was designed for high power situations. In high power circuits resistors are a great tool for reducing current but they also produce high amounts of heat and when pushed to their limits they can even start to glow red hot and burn out. In cases of where you need to have a resistor for higher wattage than 2W then you need to use the wire wound resistor.

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