Unit-I Electronic Components Electronic Components The main components used in electronics are of two general types: passive and active. (i)Active components Components required to be powered in some way to make them work i.e. rely on a source of energy Examples: Active components include amplifying components such as Vacuum Tubes, Transistors, Integrated Circuits, etc (ii) Passive components Doesn't rely on a source of power. Examples: Passive components include components such as resistors, capacitors, and inductors.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Unit-I Electronic Components
Electronic Components
The main components used in electronics are of two general types: passive and
active.
(i) Active componentsComponents required to be powered in some way to make them work i.e. rely on a source of energy
Examples: Active components include amplifying components such as Vacuum Tubes, Transistors, Integrated
Circuits, etc
(ii) Passive componentsDoesn't rely on a source of power.
Examples: Passive components include components such as resistors, capacitors, and inductors.
Resistor
Resistors decrease the intensity of the electric current flowing through a circuit. Resistors do not block
electricity. Instead, they convert a percentage of the electric current into heat energy, which is transmitted
into an area around the device.
Resistance: The ability of the material to oppose current.
The amount of electric current absorbed by a resistor is called "resistance," and is measured in "ohm" units
Ohm: an ohm is defined as the electrical resistance between two points of a
conductor when a constant potential difference applied between these points produces a
current of one ampere
R = V / I
A simple analogy with a hydraulic system. Notice that the flow of electricity resembles the flow of water
from a point of high potential energy (high voltage) to a point of low potential energy (low voltage). In
this simple analogy water is compared to electrical current, the voltage Difference is compared to the
head difference between two water reservoirs, and finally the valve resisting the flow of water is
compared to the resistor limiting the flow of current.
There won’t be any flow of current between 2 points if there is no potential difference between them.
In other words, for a flow of current to exist, there must be a voltage difference between two points.
The electric current in a conductor will increase with the decrease of the resistance, exactly as the rate
of flow of water will increase with the decrease of the resistance of the valve.
A lot more deductions are based on this simple analogy, but those rules are summarized in
the most fundamental equations of electronics: Ohm's law.
Ohm's law states that, at constant temperature the current through a conductor between two
points is directly proportional to the potential difference or voltage across the two points,
and inversely proportional to the resistance between them.
The mathematical equation that describes this relationship is: R = V / I
Where
I is the current through the conductor in unit of ampere,
V is the potential difference measured across the conductor in unit of volt,
R is the resistance of the conductor in unit of ohm.
Note: Problem to be solved.
Resistor colour code
Four band resistor colour code
•1st band provides the first digit of the
Code
•2nd band provides the second digit of
the code
•3rd band is the multiplier
•4th band indicates the tolerance value
Resistance colour code chart
Resistors
Resistor colour code calculation
• The first band red has a value of 2
• The second band violet has a value of 7
• The third band has a multiplier of x 10
• The last band indicates a tolerance value of +/-5%
• Resistance value is 270Ω +/-5%
27x10+/-5%
Small value resistors (less than 10 ohm)
The standard colour code cannot show values of less than 10 . To show these
small values two special colours are used for the third band:
gold which means × 0.1 and
Silver which means × 0.01.
The first and second bands represent the digits as normal.