## A resistor is the most important electrical component in almost every electronic circuit, it can limit current to any load such as led, transistor, opamp, etc.

### We must read resistor color code if we want to know the resistive value, tolerance, temperature coefficient. Resistors have different color bands (3,4,5,6) the more color bands the more resistor's information.

**Now let's start with 3 bands resistor color code.**

**The above resistor has only 3 bands First digit, Second digit, and multiply. A 3 bands resistor color code has fixed**+/- 20% tolerance that means if color code value is 1,000 ohms the real life resistive value may be +/- 200 ohms.

**4 band resistor color code**

**A 4 bands resistor color code has tolerance value color strip, the resistor on an above picture has 5% tolerance. This type of resistor uses in a regular circuit such as television,radio,washing machine.**

**5 bands resistor color code**

**A 5 bands resistor color codes have third digit color bands.**

**1(first digit) 0(second digit) 0(third digit) = 100 x 0.1(multiply) = 10 ohms +/- 1% (brown) tolerance. The resistor is good for opamp,power amp negative feedback because it has a very accurate resistive value.**

**6 bands resistor color code**

**A 6 bands resistor color code. The sixth band uses for temperature coefficient value, this type of resistor use for the circuit that must be precise over wide range temperature.**

####
**SMD resistor code**

####
**SMD resistor use number instead of color code, the last digit use as a multiplier for the first, second, and third digit (some SMD resistor has four numbers). The multiplier value increase by a factor of ten each time number increase by 1. **

**The last digit value:**

0 = x 1

1 = x10

2 = x100

3 = x1000

4 = x10,000

5 = x100,000

6 = x1,000,000

7 = x10,000,000

8 = x100,000,000

9 = x1,000,000,000

**Example**.

680 = 6 8 x 1 = 68 ohms

681 = 6 8 x 10 = 680 ohms.

682 = 6 8 x 100 = 6800 ohms or 6.8 kilo-ohms

1111 = 1 1 1 x 10 = 1110 ohms or 1.11 kilo-ohms

You may see 0R5, 4R7 resistor code and may don't know how to read it, now your problem will be gone.

0R5 = 0.5 ohms

4R7 = 4.7 ohms

The R value is like a "." for a resistor code.

ConversionConversion EmoticonEmoticon