About Resistors Resistance and their coding system..%to smallsmile

Definition

Resistors are passive electronic components designed to restricts the flow of current that passes through it.
Their main function is to adjust the power in different parts of the circuit so that other components can function ultimately. Resistors seem to be the most used electronic component.

Basic Circuit symbol

Types of resistors based on makeup

• Carbon Film Resistor
• Metal Film Resistors.
• Carbon Composition Resistors.
• Thin Film Resistors
• Wire wound Resistors.
• Thick Film Resistors.
• Metal Oxide Resistors.
• Cermet Oxide Resistors

Types of resistors based on function

• Fixed resistor
• Variable resistor
• Thermistor
• Photoresistor
• Potentiometer
• Varistor

Resistance
Resistance is the amount of difficulty a current encounters as it attempts to flow through a resistor. The quantity of opposition posed by a material to the flow of current.

Resistor colour coding

Colour	Value	Multiplier
Black	0	-
Brown	1	X 10 1
Red	2	X 10 2
Orange	3	X 10 3
Yellow	4	X 10 4
Green	5	X 10 5
Blue	6	X 10 6
Violet	7	X 10 7
Gray	8	X 10 8
White	9	X 10 9
Gold	5%	-
Silver	10%	-

Resistors Proposed Value
Manufacturers use a colour coding System to indicate the value of a resistor. The colour coding system is often made up of four bands of colours.

The first two colours are values, the third colour is a multiplier while the last colour indicates the level of tolerance.

Example 1

The value of the first colour is RED
The value of the second colour is RED
The function of the multiplier colour is X 10³
The value of the last colour is + or - 5%

So the value is 2 2 x 10³ = 22000

⁵/100 * 22000 = 1100

5% = 1100
Actual value 22000
+5% = 22000 + 1100 maximum of 23100
-5% = 22000 - 1100 minimum of 20900

Any value ranging from 20900 to 23100 is accepted for this resistor. Nothing less and nothing more.

Examples 2

This resistor has the following colours as it's resistance:
Brown Black Brown Gold
1 0 X 10¹ [+ or - 5%]

1 0 X 10¹ = 100

⁵/100 * 100 = 5

5% = 5
Actual value 100
+5% = 100 + 5 maximum of 105
-5% = 100 - 5 minimum of 95

Any value ranging from 105 to 95 is accepted for this resistor. Nothing less and nothing more

Examples 3

This resistor has the following colours as it's resistance:
Red Red Red Gold
2 2 X 10² [+ or - 5%]

1 0 X 10² = 1000

⁵/100 * 1000 = 50

5% = 50
Actual value 1000
+5% = 1000 + 5 maximum of 1005
-5% = 1000 - 5 minimum of 995

Any value ranging from 1005 to 995 is accepted for this resistor. Nothing less and nothing more

After getting the expected value from the colour code, an ohmmeter has to be used for confirmation.