Basic electronics

Diode

• Diode allows current in only only direction
• P-side is called anode and n-side is called cathode

What is rectifier? 

• Convert AC to DC

What is inverter?

• Convert DC to AC

Half Wave Rectifier

• The Half wave rectifier is a circuit, which converts an ac voltage to dc voltage.

Full-wave rectifier

A full-wave rectifier is a type of rectifier which converts both half cycles of the AC signal into pulsating DC signal.

Bridge rectifier 

• It is type of full way rectifier
• Four or more diodes to efficiently convert AC to DC

Zener diode

Zener diodes are specifically designed to operate under reverse break down conditions and found that when a particular voltage is reached it breaks down.

Light-Emitting Diode

Light-Emitting Diode is an electronic device that emits light when an electrical current is passed through it.

• It is p-n junction diode
• light emits in the forward biased

Photodiode

A photodiode is a semiconductor device that converts light into an electrical current. The current is generated when photons are absorbed in the photodiode. Photodiodes may contain optical filters, built-in lenses, and may have large or small surface areas.

• Photo conductive mode
• Photo voltaic mode

Resistor

It is used to reduce current flow and adjust signal level to divide voltages

variable resistor

It is adjustable resistor act as preset control within the circuit

Thermister

This is a type of resistor which has a resistance that changes with TEMPERATURE

• PTC - Resistance increase with temperature
• NTC - Resistance decrease with temperature

LDR (Light Dependent Resistor)

It is depend on the light when light falls on the LDR then the resistance decrease and increase

Uses

• On off light relay
• As a light meter to measure  intensity of light

Cells

Primary cell

• can be used only once
• zinc carbon battery
• Alkaline battery

Secondary cells

• can be reused by charging
• Lead acid
• Lithium ion
• Lithium polymer

Relay

Mechanically controlled electrically activated switch.

uses

• To switch from low current to high current

Transistors

• Transistor is a electronic device made of three layers of semiconductors materials that can act as an insulator and a conductor.
• The three layered transistor is also known as the pipolar junction transisitor.

Bipolar junction transistors(BJT)

The term bipolar refers to the use of both holes and electrons as charge carriers in the transistor structure.

There are two types of BJT

• NPN
• PNP

Region of transistor

• Emitter-Heavily doped
• Base -Lightly doped
• Collector -Moderately doped

It can work either as an amplifier or a switch

Transistor as amplifier

Due to small changes in base current the collector current will mimic the input with greater amplitude

Transistor as switch

The transistor is normally operated alternately in cut of and saturation region.

Types of transistors

• BJT(Bipolar Junction Transistor)
• UJT(UnipolarJunction Transistor)
• FET(Field Effect Transistor)
• MOS(Metal Oxide Transistor)

operating region of BJT

• Cut of region
• Linear region
• saturation region