Transcript Lecture-1 - Dr. Imtiaz Hussain

Electronic workshop
Lecture-1
Power Supplies & Measuring Instruments
Dr. Imtiaz Hussain
email: [email protected]
URL :http://imtiazhussainkalwar.weebly.com/
Outline
•
•
•
•
•
Course Objectives
Course Outline
Recommended Books
Marks Distribution
Workshop#1
– Introduction to Electronics
– Electronics vs. Electrical
– Electricity
– A.C vs. D.C
– Power Supplies
– Measuring Instruments
Course Objectives
• Hands on experience with the use of laboratory
equipment.
• Recognize discrete components and ICs.
• Read and understand the data sheets.
• Working experience with prototype board and
solder and desolder the discrete components on
a project board.
• Assemble simple circuits over a PCB.
Course Outline
Operation of
Electronic
Equipment
• Voltmeters
• Ohmmeters
• Ammeters
• Power supplies
• function generator
• Oscilloscope
Passive
Components
• Resistor
• Capacitor
• Inductor
Active
Components
• Diode
• Types
• Datasheets
• Transistor
• Types
• Datasheets
Circuit
Assembly
• Bread Board
• Circuit Assembly
• Vero Board
• Soldering
• De-soldering
• PCB
• Layout
Recommended Books
• Dr. B.S. Chowdhry & Ahsan A. Ursani, “The First Practical Book
on Electronic Workshop”, published by Mehran Infotech
Consultants, Hyderabad,
• Paul Horowitz & Ian Robinson, "Laboratory Manual for Art of
Electronics”, Cambridge University Press.
• Bernard Grobe, "Basic Electronics".
• Paul B. Znbar, Albert P. Malvino, "Basic Electronics Text Lab
Manual", McGraw Hill.
Prerequisites
• Physics (Intermediate Level)
Marks Distribution
Theory
Practical
Total Marks = 00
Total Marks = 50
Sessional Marks = 20
• Attendance = 05 marks
• Case Study/Project/ Test = 15
marks
 Midterm Exam
Final Exam Marks = 30
What is Electronics?
• General Definition
– The science dealing with the development and
application of devices and systems involving the flow
of electrons in a vacuum, in gaseous media, and in
semiconductors.
• Modern Definition
– The science dealing with the development and
application of devices and systems involving the flow
of electrons in semiconductors.
Electronics vs. Electrical
• According to Wikipedia
– Electrical Engineering is a field of engineering that
generally deals with the study and application of
electricity, electronics, and electromagnetism.
– Electronic Engineering, is an engineering discipline
where non-linear and active electrical components
such as electron tubes, and semiconductor devices,
especially transistors, diodes and integrated circuits,
are utilized to design electronic circuits, devices and
systems.
Electronics vs. Electrical
Main Difference
– Electrical Engineering
• Study and utilization/ Application of flow of electrons
– Electronic Engineering
• Study and utilization/ Application of flow of charges
(Electrons or holes)
Electricity
• Two forms of electricity
– Static Electricity is an electrical charge at rest
– Produced by either magnetism, chemicals, light,
heat, or pressure
Produced Electricity
•
•
•
•
•
Magnetism – Electric Generators
Chemical – Battery, Fuel Cells
Light – Photocell (solar cell)
Heat – Thermocouple (nuclear power)
Pressure - Crystals
Alternating Current
• If the high & low voltage terminals switch locations
periodically, the current will flow “back and forth” in the
circuit. This is called alternating current (AC).
Alternating Current
• It is the form that comes in our house mains. It has a
magnitude of 220V and a frequency of 50Hz.
Direct Current
• If the voltage is maintained between two points in a circuit,
charge will flow in one direction - from high to low
potential. This is called direct current (DC)
AC vs. DC
• Most of the home appliances run on D.C.
• Each home appliance is equipped with its own
power supply.
• Why we are supplied AC when most of the
appliances run on D.C?
Symbols of Power Sources
Power Supply
• A power supply is a device that supplies electric power to
an electrical load.
Task#1
• Your first task is to list all the power supplies available in this
lab and fill out the following table.
S. N.o
Model
Type (Tick the Relevant Choice)
AC
1.
2.
3.
4.
5.
DC
Voltage
Current
Range
Measuring Instruments
• A measuring instrument is a device for measuring
a physical quantity.
• Instruments for measuring electrical quantitates
–
–
–
–
Voltmeter (for measuring Voltage)
Ammeter (for measuring current)
Ohmmeter (for measuring resistance)
Multimeter (for measuring all three quantities)
Voltmeter
• AC and DC Voltmeters
Voltmeter
• Voltmeters have high impedance and hence are
connected in parallel across the points between which
potential difference is to be measured.
Voltmeter
Ammeter
• AC and DC ammeter
Ammeter
• Ammeters, on the other hand exhibit a very small
resistance, and hence are connected in series,
Ammeter
Ohmmeter
Ohmmeter
• Analog vs Digital
Multimeter
Digital Multimeter
• A multimeter is has three parts:
– Display
– Selection Knob
– Ports
Digital Multimeter
• Two probes are plugged into
two of the ports on the front of
the unit.
• COM stands for common and is
almost always connected to
Ground or ‘-’ of a circuit.
• The
COM
probe
is
conventionally black but there
is no difference between the
red probe and black probe
other than color.
Digital Multimeter
• 10A is the special port used
when measuring large currents
(greater than 200mA).
• mAVΩ is the port that the red
probe is conventionally plugged
in to.
• This
port
allows
the
measurement of current (up to
200mA), voltage (V), and
resistance (Ω).
Task#2
• Your second task is to list all the measuring instruments available
in this lab and fill out the following table.
S.
N.o
Model
Type
(Analog/
Digital)
1.
2.
3.
4.
5.
V AC
Measured Quantity
I AC
V DC
I DC
R
Measuring voltage Using Digital Multimeter
• To start, let’s measure voltage on a AA battery: Plug the
black probe into COM and the red probe into mAVΩ.
• Set the multimeter to “2V” in the DC
(direct current) range
• Connect the black probe to the battery’s
ground or ‘-’ and the red probe to power or
‘+’
Measuring resistance Using Digital Multimeter
• Pick out a random
resistor and set the
multimeter to the 20kΩ
setting
Measuring Current Using Digital Multimeter
• Reading current is one of the trickiest and most insightful readings in
our world of electronics.
• It’s tricky because you have to measure current in series.
Continuity Testing Using Digital Multimeter
• Continuity testing is the act of testing the resistance between two
points.
• If there is very low resistance (less than a few Ωs), the two points are
connected electrically and a tone is emitted.
• If there is more than a few Ωs of resistance, than the circuit is open
and no tone is emitted.
• This test helps insure that connections are made correctly between
two points.
• This test also helps us detect if two points are connected that should
not be.
Continuity Testing Using Digital Multimeter
• Set the multimeter to ‘Continuity’
mode. It may vary among DMMs,
but look for a diode symbol with
propagation waves around it (like
sound coming from a speaker).
Task#3
• Take a digital multimeter and fill in the following table for any
of the Voltage Sources
S N.o
1.
2.
3.
4.
Selected Voltage
(a)
Measured Voltage
(b)
Percent Error
𝒂−𝒃
× 𝟏𝟎𝟎
𝒂
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END OF LECTURE-1