Chapter 1

Quick review over Electronics and Electric Components

Prepared By : Elec Solv

Quick review over Electronics & Electric Components :-

1. Resistors2. Capacitors .3. Switches and Relays .4. Diodes .5. Transistors .6. Voltage Regulators .7. Operation Amplifiers .8. Logic Gates .9. Boards .

1. Resistors

Definition .Usage .Connection in the Circuit .Types .Power Budget .

• Definition

Resistor is a passive component that prevents the current to pass in the electric circuit .

V = I . R Where : V = The Voltage across the resistor in Volts . I = The Current passing in the resistor in Amperes . R =The Value of the resistor in Ohms .

• Connection in the circuit

Parallel Connection . The Voltage is constant . The Current is divided .

Series Connection . The Voltage is divided . The Current is constant.

• Connection in the circuit

Pull Up Resistor

Pull Down Resistor

• Types

Types of Resistors

Variable Fixed

oReadings table for Fixed Resistors

o Fixed Resistors

o Variable Resistors

Resistors values is being changed manually potentiometer Trimmer

o Variable Resistors

Resistors change its value due to physical phenomena :-

LDR - Light Dependant Resistance – the value of this resistance is inverse proportion with the amount of light falling on it .

Thermistor , and so many types .

• Power Budget

We mean by Power Budget , the maximum power that the resistor can withstand without being damaged .

2. Capacitors

Definition .Types .Application .

• Definition

A Capacitor consists of two plates between them there is a dielectric material and it store electrical energy .

• Types

Polarized :- We must wire the anode

to positive terminal to the battery and the cathode to the negative terminal of the battery .

Non-polarized :- No anode or cathode .

• Application

Smoothing the signals like in Rectifier Circuits .

Used with other ICs to make them do some functions .

3. Switches and Relays

Definition .

Rating .

Types .

• Definition of a Switch

A Switch is a component that allows us to make the circuit opened or closed circuit .

• Definition of a Relay

A Relay is an electromechanical switch , that means that it is a normal switch but it is controlled electrically as we see in the figures .

o Rating of switches

Switches’ rating is :-

Max current that can pass through it without having a fault .

The max voltage that could be applied across it without having a fault .

o Rating of Relays

Relays’ rating is :- The value and type of the

voltage applied across the coil to energize the electromagnetic field .

The max current can pass through the contact without having a fault .

The type and max value of the voltage applied across the contact without having a fault .

• Types

Switches and Relays can be classified according to many characteristics like rating , pole and throw and applications .We will discuss the basic of two classifications .

• Pole and Throw

Pole : is the piece of copper that connects the current in the switch Throw : is the point that the pole touches when connecting the current .We can say they are :

SPST DPDT And so many of them .

• According to Operation

Limit SwitchOn – Off – ON switchOn – off switch Push button Present Sensor And so may types

4. Diodes

Definition .Meter Check .Types .Application .

• Definition

A Diode is an electronic gate that allow the current to flow in one direction .

• Meter Check

Use the Multi-meter on the Buzzer mode , and wire its two terminals to the 2 sides of the diode then:-

The Multi-meter will read very high value if the diode is reversed .

The multi-meter will read very low value if the diode is forward biased .

• Types

There are many types of diodes like :-

Normal Diode . Zener Diode . LED – Light Emitting Diode - . Some other types . Note that a Bridge is

combination of 4 diodes .

• Application

Diodes are used in several application like :-

Half-wave rectifier circuit . Power Supply Circuits . Protect electronic circuits .

5. Transistors

Definition & Types .Meter Check .Modes .Application .

• Definition & Types

The Transistor is a three-terminal component . It is used as amplifier or electronic switch and so many usages .We will learn about BJT transistor , and it has two types :-

NPN PNP

• Meter Check

We’ll put the Multi-meter on the Buzzer mode and check each PN junction in the transistor .

• Modes

Transistor has 3 modes of operating :-

Saturation ( as a closed switch ) .

Cutoff ( as an opened switch ) .

Active mode ( as an amplifier) .

• Application

Relay Driver Circuit

6. Voltage Regulators

Definition .

Types .

Application .

• Definition

It is designed to adjust the current passing through the load – so it maintains a constant output voltage – by comparing the supply’s DC output voltage with a fixed or programmed reference voltage .

• Types

Fixed Positive ( 78xx series ) Negative (79xx series)

Adjustable

• Applications

Power Supply Circuit .

7. Operational Amplifiers

Definition .Modes .Application .

We will deal with 741 IC while there are many types of Op Amps .

• Definition

Operational Amplifier is an IC that is designed to do several functions like :-

Amplifying Signals . Comparing between two

signals . Summing Signals . And so many applications .

• Modes

Comparator .Inverting .Non-inverting .Summer .Differentiator .And other modes .

• We can use :-

The formula (V1 - V2 ) A = Vout

A = The Gain .V1 = Input Voltage on the non-inverting pin .

V2 = Input Voltage on the inverting pin .

Vout = Output Voltage .

• Inverting , Non-inverting

Inverting :- Amplifies the signal with

a controlled gain .

Non-inverting :- Amplifies the signal with a

controlled gain and invert it .

A = Vout / Vin = - Rf / Ri

A = Vout / Vin = 1 + (Rf / Ri)

• Comparator

At Vinput > Vref

Vo=+Vsupply

At Vinput < Vref

Vo=-Vsupply

• Application

Light advanced switch

8. Logic Gates

Logic gates have many different families and types but we will discuss :-

AND OR NOT

• NOT gate 7404

• AND gate 7408

• OR gate 7432

• Application

They are the main structure of the logic designs .Used in the integrated circuits to make flip flops , counters and shift registers and so on .

9. Boards

DefinitionTypes of boardsTypes of componentsHow to make a PCB

• Definition

It is a board that allows us to wire the electronic component together with little number of wires .

• Types

Bread board Just used once and we

use tin to fix the component to it .

Test Board Can be used several

times as the component are fixed and can be replaced from it

• Types of Components

Surface mount Components that don’t

need drilling in the board .

Through hole Components that need

drilling in the board .

• How to make a PCB ?!

PCB is the way we translate the simulated circuits into our physical world. It has a 3 way of representation.

1- Prepared PCBs 2- Manual PCBs 3- Semi Manually PCBs

There are fully automated processes where we use machines to finish the PCB.

Questions ?

End