basic-electronics

1. Basic Electronics

2. Electronics Theory
the branch of physics that deals with the emission and effects of
electrons and with the use of electronic devices
WHAT IS MATTER ?
Scientifically we define matter as all the "material" things
about us.
- Occupies space
- Has mass

3. Classes Of Matter
• Solid
- Within a solid, atoms/molecules are relatively close together, or "rigid";
- of definite shape and volume; firm; neither liquid nor gaseous; "ice is water
in the solid state"
• Liquid
- Liquid is a phase of matter in which the molecules are close together and
can move around slowly.
• Gas
- Gas is a phase of matter in which the molecules are widely separated,
move around freely, and move at high speeds

4. Matter Composition
“A matter can be broken down into smaller pieces”
ATOMS
a. Protons – positively charged particles
b. Neutrons – uncharged particles
c. Electrons – negatively charged particles

5. Atom Structure

6. The Law of Electromagnetic
Charges
• The law states:
Like charges repel, and unlike charges attract
+
positive negative
-
+
positive
Repel
No attraction occurs
attraction

7. Conductor and Insulator
• Conductor
- Materials which easily allow the flow of electrons from 1 point to
another.
ex. Iron, Copper, Gold
• Insulator
- Materials which don't allow the flow of electrons from 1 point to
another.
ex . Plastic, rubber, wood

8. Difference Of Potential
+
-
If we connect a copper wire between two oppositely
charged bodies, an electron flow would result.

9. Difference Of Potential
• Electric potential is the potential energy per unit of
charge.
• Voltage is the difference of electrical potential between
two points of an electrical network, expressed in volts.
+ -- +
PE PE PE PE
+
PE
-
PE
WIRE WIRE
Electrical Pressure

10. CURRENT
• Electric current is by definition the flow of electric charge.
• The unit of measure for this parameter is Ampere
wire
Active wire
Current is present

11. Types Of Current
• Direct Current
- Direct Current is the movement of an electrical charge in one direction.
• Alternating Current
- An alternating current (AC) is an electrical current where the magnitude and
direction of the current varies cyclically

12. Measurement of Current
• The magnitude of current is measured in AMPERES. A current of one ampere is
said to flow when one coulomb of charge passes a point in one second.
Remember, one coulomb is equal to the charge of 6.28 x 10 to the18th electrons.
• Frequently, the ampere is much too large a unit for measuring current. Therefore,
the MILLIAMPERE (mA), one-thousandth of an ampere, or the MICROAMPERE
(µA), one-millionth of an ampere, is used. The device used to measure current is
called an AMMETER and will be discussed in detail in later.
i - current
Example: 1 Ampere

13. Resistor
• Electricity, according to Benjamin Franklin, acts like a
fluid. It flows and has a measurable CURRENT . We can
restrict its flow by adding electrical friction. We say that
the restriction of electrical flow is called RESISTANCE
and that a device which causes such RESISTANCE is
called a RESISTOR . All materials, even the very best
CONDUCTORS demonstrate a certain amount of
RESISTANCE to electron flow.

14. RESISTOR IMAGE
FIXED RESISTOR VARIABLE RESISTOR
Resistors used in computers and other devices are typically much smaller,
often in surface-mount packages without wire leads.
This is the most general purpose, cheap resistor.
Usually the tolerance of the resistance value is ±5%.
Power ratings of 1/8W, 1/4W and 1/2W are frequently used.
CARBON FILM RESISTOR
CERAMIC RESISTOR
POTENTIOMETER

15. HOW TO READ THE RESISTANCE OF THE RESISTOR

16. From the top of the photograph
1/8W
1/4W
1/2W
Rough size
Rating
power
(W)
Thickness
(mm)
Length
(mm)
1/8 2 3
1/4 2 6
1/2 3 9
RESISTOR ANALYSIS

17. Resistance
• In order to compare the resistance of various materials, we need to
have some standard unit of measurement. The unit of measurement
for resistance is called the Ohm , and is indicated by the Greek
letter Omega ( Ω ).
Less number of electrons are allowed to pass through
More current
RESISTANCE TO FLOW

18. Resistance
• Although Ohm is the basic unit, Kilo Ohm and
Mega Ohm are frequently used. 1 Kilo Ohm (K
Ω) is equal to 1 thousand Ω. 1 Mega Ohm (M &
Omega) is equal to 1 million Ω.
• Ex
- 8 M Ohm = 8,000,000 Ohm = 8,000 K Ohm

19. Resistance
There are 4 factors that determine the resistance of a material
(1) Type of Material
- The resistance of various types of materials are different. For
instance, gold is a better conductor of electricity than copper, and
therefore has less resistance.
(2) Length
- The resistance of a material is directly proportional to it's length.
The longer the material is, the more resistance it has. This is
because the electrons must flow through more material, and
therefore meets more friction over the entire distance.

20. Resistance
(3) Cross Sectional Area
- The resistance of a material is inversely proportional to the
cross sectional area of the material. This means that the thicker the
substance is across, the lower the resistance. This is because the
larger the cross sectional area is, the less friction there is over a
given length.
D
R = p L
A
Area is directly proportional to diameter
A = pie (R squared)
R = radius
D = 2R, diameter

21. Resistance
• (4) Temperature
- In various types of materials, resistance can vary inversely or directly with
the temperature. This is because of the chemical properties of the material.
In Carbon, for instance, the resistance decreases as the temperature rises.
So we say it varies inversely. In copper, however, the opposite is true, with
the rise in temperature, we have a rise in the resistance.
Resistance then, is basically a form of friction which restricts the flow of an
electrical current. In basic science class, you learned that by putting your
hands together, and rubbing them quickly, your hands get warm. This is
because friction generates heat. Electrical friction - RESISTANCE - also
generates heat.

22. Direct Current Theory
• The current leaves the
battery at the negative
terminal, flows through
the bulb, and returns to the
positive terminal of the battery.
The electrons flow in one
direction. This is known in
electronics as DIRECT
CURRENT flow because the
electrons flow only in one direction.

23. Direct Current Theory
• As long as we can follow the current from the negative terminal of
the battery throughout the entire circuit, and back to the positive
terminal, we have a COMPLETE CIRCUIT
• In order to have any complete circuit, you are required to have at
least 3 parts:
a. The SOURCE or SUPPLY of Voltage.
b. The LOAD which uses the source Voltage.
c. A complete path of connecting wires.

24. THE BASIC ELECTRIC CIRCUIT
• LOAD
- is any device through which an electrical current flows and which
changes this electrical energy into a more useful form.
• SWITCH
- which permits control of the electrical device, interrupts the current
delivered to the load.
• SOURCE
- is the device which furnishes the electrical energy used by the
load.

25. SCHEMATIC REPRESENTATION
The schematic diagram
- is a "picture" of the circuit that uses symbols to represent the various
circuit components; physically large or complex circuits can be
shown on a relatively small diagram.

26. A SIMPLE SCHEMATIC DIAGRAM

27. What happens to the path for
current when S1 is open as
shown in the figure?
Practice Reading Schematic Diagram

28. OHM'S LAW
• In the early part of the 19th century, George Simon Ohm proved by experiment that
a precise relationship exists between current, voltage, and resistance. This
relationship is called Ohm's law and is stated as follows:
• The current in a circuit is DIRECTLY proportional to the applied
voltage and INVERSELY proportional to the circuit resistance.
Ohm's law may be expressed as an equation:

29. • As stated in Ohm's law, current is inversely proportional to resistance. This means,
as the resistance in a circuit increases, the current decreases proportionately.
OHM'S LAW

30. Capacitor Theory

31. Capacitor Theory
• Capacitor “ENERGY STORAGE”
- A capacitor basically consists of two plates with an insulator in
between, although in practice the 'plates' are normally rolled up in a
can to save space. It can be used in a circuit to store charge for
small periods of time.
Plate I
Plate II
Charges will attracted to other
side of the plate
Separation called Dielectric

32. • The plate on the capacitor that attaches to
the negative terminal of the battery accepts
electrons that the battery is producing.
- The plate on the capacitor that attaches to
the positive terminal of the battery loses
electrons to the battery.
- Once it's charged, the capacitor has the same voltage as the battery (1.5 volts on the
battery means 1.5 volts on the capacitor).
- For a small capacitor, the capacity is small. But large capacitors can hold quite a bit
of charge.
Capacitor Theory
1.5 V
Capacitance = is the property of a capacitor, a device, or an electric circuit that defines its
ability to store an electrical charge (or energy) when a given voltage is applied, measured in
farads (F)

33. • Ceramic Capacitor
Capacitors
Electrolytic Capacitor
Ceramic capacitors are small in size and value, ranging from a few Pico Farads
to 1 µF. Not polarized, so either end can go to ground.
Electrolytic capacitors look like small cylinders and range in value from 1 µF to
several Farads. Very inaccurate and change in value as the electrolytic ages.
Polarized, cathode must go to ground. Cathode is marked with a minus sign on
case. Value is usually written on case.
Tantalum capacitors
Tantalum capacitors are similar in size to ceramic but can hold more charge, up
to several hundred µF. Accurate and stable, but relatively expensive. Usually
Polarized, anode is marked with a plus sign.

34. • The unit of capacitance is a farad. A 1-farad capacitor can store one
coulomb (coo-lomb) of charge at 1 volt.
• A coulomb is 6.25e18 (6.25 * 10^18, or 6.25 billion billion) electrons.
Applications
- Sometimes, capacitors are used to store charge for high-speed use. That's
what a flash does. Big lasers use this technique as well to get very bright,
instantaneous flashes.
- Capacitors can also eliminate ripples. If a line carrying DC voltage has
ripples or spikes in it, a big capacitor can even out the voltage by absorbing
the peaks and filling in the valleys.
- A capacitor can block DC voltage. If you hook a small capacitor to a battery,
then no current will flow between the poles of the battery once the capacitor
charges
Capacitor Theory

35. • Capacitors in Series:
Putting capacitors in series reduces the overall capacitance:
Capacitor Theory
(1/C) = (1/C1) + (1/C2) + (1/C3) .....

36. • Capacitors in parallel:
• Putting capacitors in parallel increases the total capacitance:
Capacitor Theory
Capacitors in parallel : C = C1 + C2 + C3

37. • For the network shown, determine the
equivalent capacitance of the network,
the charge on each capacitor, and the
potential difference across each.
We have a capacitor network to solve. Hence the first step is to
determine the equivalent capacitance of the network.
C' = C1 + C2 = 1 nf + 2 nf = 3 nf
1/Ceq = 1/C' + 1/6 nf = 1/3 + 1/6 = (2 + 1)/6 or Ceq = 2 nf
Capacitor Problem
30V
6nf
2nf1nf

38. Inductor Theory

39. • An inductor is an energy storage device. It can be as simple as a
single loop of wire or consist of many turns of wire wound around a
special core. Energy is stored in the form of a magnetic field in
around the inductor.
Inductor Theory

40. • The Basics
In a circuit diagram, an inductor is shown like this:
Inductor Theory
To understand how an inductor can work in a circuit, this figure is helpful:
Most of the current should follow the low-resistance
path through the loop. What happens instead is that
when you close the switch, the bulb burns brightly
and then gets dimmer. When you open the switch,
the bulb burns very brightly and then quickly
goes out.

41. Inductor Theory
The reason for this strange behavior is the inductor.
When current first starts flowing in the coil, the coil
wants to build up a magnetic field. While the field
is building, the coil inhibits the flow of current. Once
the field is built, current can flow normally through
the wire. When the switch gets opened, the
Magnetic field around the coil keeps current flowing
in the coil until the field collapses. This current
keeps the bulb lit for a period of time even though
the switch is open.
In other words, an inductor can store energy in its
magnetic field, and an inductor tends to resist any
change in the amount of current flowing through it.
Inductance = The property of an electric circuit that
opposes a change in current flow.

42. • LT = L1 + L2
• L= Inductance
• Henry is the unit of measure for L
• Parallel Inductors
(1/Ltotal) = (1/L1) + (1/L2) + (1/L3) .....
Series and Parallel Inductor

43. • Diode
- diode is a component that restricts the direction of movement of
charge carriers. It allows an electric current to flow in one direction,
but essentially blocks it in the opposite direction.
Diode Theory

44. • Rectifier.
- An electronic device with two
wires or terminals. A rectifier
allows electrical current to flow
through in only one direction
and is used for converting
alternating current into direct
current.
Diode Theory
Zener

45. • Rectifier.
- An electronic device with two
wires or terminals. A rectifier
allows electrical current to flow
through in only one direction
and is used for converting
alternating current into direct
current.
Diode Theory
Zener Diode = Voltage
Regulator

46. • Biasing
Diode Theory
Forward Bias
DIODE

47. • REVERSE BIAS
Diode Theory

48. ATX Power Supply

49. Power Supply
• A power supply (sometimes known as a power supply unit or PSU)
is a device or system that supplies electrical or other types of
energy to an output load or group of loads. The term is most
commonly applied to electrical energy supplies.
• The most common computer power supply is built to conform with
the ATX form factor. This enables different power supplies to be
interchangeable with different components inside the computer.
At the motherboard
At the Cable

50. • The ATX (for Advanced Technology Extended) form factor was
created by Intel in 1995. It was the first big change in computer case
and motherboard design in many years.
• ATX overtook AT completely as the default form factor for new
systems. ATX addressed many of the AT form factor's annoyances
that had frustrated system builders.
A T X Connector Standard
AT POWER CONNECTOR

51. Advanced Technology Standard
A T Standard

52. • In 2003, Intel announced the new BTX standard, intended as a
replacement for ATX. BTX (for Balanced Technology Extended) is a
form factor for PC motherboards, originally slated to be the
replacement for the aging ATX motherboard form factor in late 2004
and early 2005.
B T X Connector Standard
At the motherboard

53. Pin Signal Description
1 +3.3 VDC
2 +3.3 VDC
3 COM Ground
4 +5 VDC
5 COM Ground
6 +5 VDC
7 COM Ground
8 PWR_OK Power good - indicate that VDC voltages
are in range.
9 +5 VSB Standby voltage
10 +12 VDC
B T X Connector Pin Designation

54. Pin Signal Description
11 +12 VDC
12 +3.3 VDC
13 +3.3 VDC
14 -12 VDC
15 COM Ground
16 PS_ON# Active low. TTL compatible (0.1-0.8V low; 2.0 high?).
When low - DC outputs are enabled. When high - power supply should
not deliver DC current.
17 COM Ground
18 COM Ground
19 COM Ground
20 N/C
21 +5 VDC
22 +5 VDC
23 +5 VDC
24 COM Ground
B T X Connector Pin Designation

55. - ATX Power
Supply connector
- Typical wattages range
from 200 W to 500 W
- There are also other,
smaller connectors, most of
which have four wires:
two black,
one red,
one yellow.
“each black wire is a Ground, the red wire is
+5 V, and the yellow wire is +12 V.”
A T X Power Connector

56. Pin Name Color Description
• 1 3.3V Orange +3.3 VDC
• 2 3.3V Orange +3.3 VDC
• 3 COM Black Ground
• 4 5V Red +5 VDC
• 5 COM Black Ground
• 6 5V Red +5 VDC
• 7 COM Black Ground
• 8 PWR_OK Gray Power Ok (+5V & +3.3V is ok)
• 9 5VSB Purple +5 VDC Standby Voltage (max 10mA)
• 10 12V Yellow +12 VDC
• 11 3.3V Orange +3.3 VDC
• 12 -12V Blue -12 VDC
• 13 COM Black Ground
• 14 /PS_ON Green Power Supply On (active low)
A T X

57. Pin Name Color Description
• 15 COM Black Ground
• 16 COM Black Ground
• 17 COM Black Ground
• 18 -5V White -5 VDC
• 19 5V Red +5 VDC
• 20 5V Red +5 VDC
A T X
At the motherboard At the cable

58. • Can I fit an ATX mainboard in an AT case?
- Not really. An AT case and AT power supply can neither power up
nor house a new ATX mainboard. ATX and AT are two different
form-factors. The AT case was designed before ATX. Most of the
computer cases built before late 1996 were AT form-factor. For over
10 years, from about 1985 to 1997, the AT form-factors, founded by
the original IBM PC-AT, provided the standard for 90% of the PC
industry. Today, the majority of new systems ATX form-factor. The
ATX is also known as the Extended AT form-factor.
Question

59. Why Weight Matters?
The more appropriate question is why size matters.
The weight of a power supply is directly related to the quantity, quality,
and size of the material (thus cost) used to build the power supply.
Choosing a Power Supply

60. • Conclusions
This brief study clearly confirms an empirical
knowledge: the quality of a power supply can be
estimated by its weight.
- The very simple and easy way for ordinary PC users to
estimate and compare the quality of a power supply.
Choosing a Power Supply

61. Prepared by: Sir Philip

62. OPERATING SYSTEM
- A software that provides a software platform on top of which other
programs, called application programs, can run.

63. • DOS
- Disk operating system, the original system used for
PCs. You type in commands instead of pointing and
clicking.
- A disk operating system is an operating system that
resides on a disk.
DOS
An example of MS-DOS's command-line interface, this one showing that the
current directory is the root of drive C.

64. • PC-DOS, MS-DOS, FreeDOS, DR-DOS, Novell-DOS,
OpenDOS, PTS-DOS, ROM-DOS and several others.
• MS-DOS from Microsoft was the most widely used
DOS Family

65. • MS-DOS 3.0, released in September 1984, first supported 1.2Mb floppy
disks and 32Mb hard disks. MS-DOS 3.1, released November that year, first
supported networking
• MS-DOS 3.2, released in April 1986, was the first retail release of MS-DOS.
It added support of 720K 3.5" floppy disks. Previous versions had been sold
to computer manufacturers, who pre-loaded them on their computers. This
is because operating systems were considered part of a computer, not an
independent product.
• MS-DOS 3.3, released in April 1987, featured logical disks. A physical disk
could be divided into several partitions which are considered as independent
disks by the operating system. Support was also added for 1.44Mb 3.5"
floppy disks.
MS-DOS Family

66. • MS-DOS 4.0, released in July 1988, supported disks up to 2GB (note that
typical disk sizes were typically 40-60Mb in 1988), and added a full-screen
shell called DOSSHELL. Similar or better shells, like Norton Commander
and PCShell, already existed in the market. This release had been
considered very buggy. On November 1988, Microsoft addressed many
bugs in a service release, MS-DOS 4.01.
• MS-DOS 5.0, released in April 1991, included the full-screen BASIC
interpreter QBasic, which also provided a full-screen text editor (previously,
MS-DOS had only line-based text editor), disk cache utility, undelete
capabilities, and other improvements. It had severe problems with some
disk utilities, fixed later in that year. The fixed version had been called MS-
DOS 5.01.
MS-DOS Family

67. • MS-DOS 6.0 had been released, On March 1993. also featured the disk
defragmenter DEFRAG, backup program MSBACKUP, memory
optimization with MEMMAKER, and rudimentary virus protection via MSAV
• MS-DOS, 6.21 (released March 1994), appeared due to legal problems.
• MS-DOS 6.22 which was released in May 1994 was the last stand-alone
version of MS-DOS available to the general public. MS-DOS was removed
from marketing by Microsoft on November 30, 2001.
• Microsoft also released versions 6.23 to 6.25 for banks and American military
organizations. These versions introduced FAT32 support. Since then, MS-DOS
exists only as a part of Microsoft Windows versions based upon Windows 95 (e.g.,
Windows 98, Windows Me).
MS-DOS Family

68. • Microsoft DOS (Disk Operating System) is a command line user
interface.
• Command line
- A prompt where the user types in a command, as opposed to
using the mouse to perform a command.
Below is a listing of the MS-DOS commands most commonly used and
that you will most likely use during a normal DOS session.
- cd,
- dir,
- copy,
- del,
- format
MS-DOS Command

69. cd
- CD (Change Directory) is a command used to switch directories
in MS-DOS.
dir
- The dir command allows you to see the available files in the
current and/or parent directories.
copy
- Allows the user to copy one or more files to an alternate
location.
You can only copy files which in their extension modes
del
- is a command used to delete files from the computer.
format
- Format is used to erase all of the information off of a computer
diskette or fixed drive.
MS-DOS Command

70. DISK PARTITION AND FORMAT
PREPARED BY: SIR PHILIP

71. • A boot disk is a removable digital data storage medium, normally
read-only, that can load (boot) an operating system or utility
program.
• Floppy disks and CD-ROMs are the most common forms of media
used, but other media, such as tape drives, zip drives and more
recently, USB flash drives can be used.
Boot Disk
ZIP DRIVE

72. - In computer engineering, hard disk drive partitioning is
the creation of logical divisions upon a hard disk that
allows one to apply operating system-specific logical
formatting.
Disk Partition

73. 1. If one partition becomes corrupt, only that partition suffers and not
the whole hard drive.
2. Often, two operating systems cannot coexist on the same
partition, or use different "native" disk formats. The drive is
partitioned into different logical disks for different OSes.
- Utility to create a disk partition is done by FDISK
Purpose of Disk Partition

74. • Fdisk is one of the more commonly used MS-DOS commands, even
today with Windows 95 and Windows 98. Fdisk allows the user to
delete and/or create partitions on the hard disk drive.
• MS-DOS 3.3x and below used fdisk.com
• MS-DOS 4.x and above uses fdisk.exe
FDisk