Basic Electronic Components and it's Uses

I hope you have read the basic things about electronics  or Click here....


Now lets see some basic electronic components and its uses........

Resistors

Resistors

In simple words, resistors are the devices which resists or blocks the flow of current. In other words resistors are used to control the flow of current in a circuit. Generally the resistors are made of materials such as carbon film, Chromium, nickel etc. The resistance in an electronic circuit is measured in ohms and is denoted by the Greek word omega (Ω). the current and voltage in a circuit is varied according to the value of resistance. As the value of resistance increases, the voltage and current decreases.

 Now lets see how to find the value of a resistor.

The value of a resistor can be easily find out. There will be 3 or more color bands on a resistor.

Each color band represents each value. This is the color code of the resistor.

We can see 3 color bands placed near by and one away from them. Generally this fourth band will gold or silver in color. Now hold the resistor in such a way that the 4^th band comes to the right side.

 Now count the colors from left to right as 1,2,3,4 etc. now see the table for the color values. Now all you have to do is that combine the first 2 color values together and multiply that value with the multiplier corresponding to the 3^rd color band.

The 4^th band denotes the tolerance of the resistor. Tolerance is the variation in the resistance value of a resistor when connected to a circuit.

The wattage of a resistor can be identified from its size. As the size of the resistor increases, the power also increases. The resistors are available in 1/4W, 1/2W, 1W, 2W, 5W, 10W etc.

Resistor color code table

For example   :

a resistor has color bands as follows

Green, Blue, Brown and Gold

from the table, the value of Green is 5, Blue is 6, Brown is 10 and Gold is 5%.

Now combine the first 2 color codes. ( Combine Green and Blue → 56 ).

Now multiply this value with the multiplier corresponding to the 3^rd band.( Multiplier of Brown is 10 Ω ).

                                   56 X 10  Ω = 560 Ω

Example 2 :

Yellow, Violet, Orange and Silver

Combine the first two codes ( Yellow & Violet → 47 )

 Multiply 47 with the multiplier of Orange (1K Ω).

                       

                                    47 X 1K Ω = 47 K Ω

NoTe  :

1K Ω = 1000 Ω

1M Ω = 1000k Ω

Capacitors

Capacitors

Capacitor is an electronic component which is used to store electric charge. The capacitor is also used as a filter in some electronic devices. The capacitors are made up of insulators such as paper, Mica, Ceramic etc which are placed in between two Metallic plates ( Electrodes ). The insulator placed in between the electrodes are called dielectric. A capacitor blocks  Direct Current ( DC) and passes Alternating Current ( AC ). There are three types of capacitors. They are....

·         Electrolytic Capacitor

·      Ceramic Capacitors

·    Variable Capacitors

The ability of a capacitor to store Electric Charge is called Capacitance. It is measured in Farad. The farad is a larger value. So in practical, we use Pico Farad (PF), Nano Farad ( NF )

or Micro Farad ( µf ).

                                                1 Farad  = 1000000  µf

                                                1  µf        = 1000 nf

                                                1 nf         = 1000 pf

Capacitor Codes and values

Please click here to find the capacitor values.

Diode

Diodes

Diode is an electronic component which which allows the current to flow only in one direction. The  diode is a semiconductor device. It allows the current to pass through it when forward biased and acts as an insulator when reverse biased . When forward biased, the barrier at the PN junction gets destroyed and the current flows through the diode and when reverse biased, the barrier at  the PN junction gets stronger and acts as an insulator. This is happened due to the repulsion of same charges or the attraction of opposite charges.

Identification of terminals   :

Hold the diode in your hand and look for a band on the diode.

The terminal near the diode is Negative ( -ve ) and the terminal which is away from the band is Positive ( +ve ).

Transistors

Transistors

A Transistor is an electronic semiconductor device which is used to amplify and switch electronic signals and electrical power. It has at least 3 terminals for connection to an external circuit. 

There are two types of transistors. They are....

·         NPN Transistors

·         PNP Transistors

A transistor in which a thin P type semiconductor is placed in between two N type semiconductor is called a NPN transistor and a transistor in which a thin N type semiconductor is placed in between two P type semiconductor is called a PNP transistor.

Transistor as a switch

Consider an NPN transistor...........

 When a Positive( +ve ) voltage is applied to the base of a NPN transistor, there will be a flow of current between the Collector and Emitter of the transistor. In other words, the transistor goes to on state when a +ve voltage is applied at the base and it goes to off state when -ve voltage is applied to the base.

IC CHIPS ( Integrated Circuit Chips )

IC chips

An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits and components such as transistors, resistors, capacitors etc. on one small plate ("chip") of semiconductor material, normally silicon. This can be made much smaller than a discrete circuit made from independent electronic components.

Inductors

Inductors

An inductor is nothing but a coil. It is as same as a capacitor but opposite in nature and properties. It blocks AC ( Alternating Current ) and passes DC ( Direct Current ). A capacitor stores energy in Electrical field on the other hand an inductor stores energy in magnetic field.

Since an inductor blocks AC signals it can be used as a filter.

Transformers

Transformer

A transformer is an electrical device which is used to increase or decrease the alternating current. A transformer has two coils ( Primary and Secondary ). The principle of a transformer is Faraday's law of Electromagnetic Induction. The input signal is given to the primary coil of the transformer. It induces an e.m.f or voltage on the secondary coil. Hence we can find an output voltage without having any changes in the freequency.

There are two types of Transformers. They are.....

•                                      Step Up Transformers
•                                      Step Down Transformers

Step Up Transformer

A step up transformer is used to produce a voltage higher than the input voltage. In a Step Up Transformer, the secondary winding is greater than the primary winding.

Step Down Transformer

A Step Down Transformer is used to produce a voltage lower than the input voltage. In a Step Down Transformer, the secondary winding is lower than the primary winding.

Generally, the transformer used in electronic circuits are Step Down Transformers.