Electronics

1        Electronics

What is electronic?

Ans. It is a science which study about the electrons.

Electrons:

Subatomic partical which have negative (-ve) change.

2        Current and Voltage:

3        Current: It is the process of flow of electrons.

Denoted by I,

Symbol 

Measured on Ampere,

1        Types

i)                    AC (Alternate current)

ii)                  DC (Direct current)

iii)                AC: Those type of current which are fluctuated (increases and decreases) are called AC current.

iv)                DC: Those types of current which are not fluctuated (fixed or constant) are called DC current.

Source of DC current are battery solar energy etc.

2        Voltage: Pressure created in the process of flow of electrons is called voltage.

Denoted by V,

Measured in Volt,

Volt is denoted by small 'v' .

3        Signal: It is flow of information.

4        Types

i)                    Analog Signal

ii)                  Digital Signal

iii)                Analog Signal: Those signals which flow continuously are called Analog signal.

iv)                Digital Signal: Those signals which are digitize are called digital signal.

O = No/ Off

1 = Yes / On

1     Electronic Components:

a.       Capacitor: It also purifies the DC current. It also generates different hertz signals with help of coil.

Symbol

Denoted by C,

∆ Capacity of capacitors are called capacitance, which are measured on Farad.

Types:

i)                    Fixed capacitor

ii)                  Variable capacitor

iii)                Semi-variable capacitor

iv)                Fixed capacitors: Those capacitors whose values are fixed are called fixed capacitors.

a)      Polarized capacitors:

b)      Non-polarized capacitors:

ii)                  Variable Capacitors: Those capacitors whose values are changeable are called variable capacitors.

iii)                Semi-variable Capacitors: Those capacitors whose value can partially changes are called semi-variable capacitors.

c)      Resister: It resists the current on the circuit-board as the requirements because a circuit-board requires different quantity of current on different areas.

Denoted by R

Its capacity is called resistance which is measured on Ohm.

Ohm is denoted by Omega.

2        Types

1)      Fixed resister

2)      Variable resister

3)      Semi-variable resister 

 Color                                                              value

Black                                                               0

Brown                                                                         1

Red                                                                 2

Orange                                                            3

Yellow                                                            4

Green                                                              5

Blue                                                                 6

Violet                                                              7

Gray                                                                8

White                                                              9

Golden +- 5%

Silver +-10 %

Notes: ∆     Black doesn't used as first color,

                        ∆    Golden and silver always comes on last.

Transformer: It increases and decreases or step up and step down the AC current as the requirements.

Made of coils,

Denoted by 'T'

Two types of coils

1.   Primary Coils

2.   Secondary coils

1.      Primary coils: It givens input.

2.      Secondary Coils: It gives output.

There are two types of Transformer:

i)                    Step Up: Those transformers which increases the input AC current.

They have more secondary than primary coils.

ii)                  Step down: Those transformers which decreases the input AC current.

They have more primary than secondary coils.

Transistor: It transfers the current from low resistance to high resistance area.

Denoted by Q,

It has three leads.

1.   Collector: It collects the current. (very long)

2.   Emitter: It emits the current.

3.   Base: It controls the flow of current.(very short) 

It made of two PIN junctions.

Types

PNP junction (                        )

NPN junction (            )

Diode

It is an electronics components whose function are depend upon their types.

Denoted by D,

It is made of one PN junction,

Positive junction is called Anode (A),

Negative junction is called Cathode (c/K).

Types:

1.      Rectifier

2.      LED (Light Emitting Diode)

3.      Photo

4.      Zener

5.      Signal

6.      Varaclor

7.      Hot carrier

8.      Tunnel