Call Now ≽ 9953056974 ≼🔝 Call Girls In New Ashok Nagar ≼🔝 Delhi door step de...
Fundamentals of electric circuits
1.
2. MY PROFILE
Name : Abdullah Al Mahfuj
Department : Textile.
Program : B.Sc. in Textile Engineering .
ID : 142014007
Green University of Bangladesh
3. Name of My Presentation
FUNDAMENTALS OF
ELECTRIC CIRCUITS
4. PRINCIPAL ELEMENTS OF
ELECTRICAL CIRCUITS
INDEPENDENT SOURCES
The voltage/current sources that have the capability of
generating a prescribed voltage or current independent of
any other element within the circuit.
These sources may output a constant voltage/current, or
they may output voltage/current that varies with time.
5. 1) Ideal Voltage Sources
An ideal voltage source is a two-terminal element that maintains
the same voltage across its terminals regardless of the current
flowing through it.
Vt = constant, no matter what the load current is.
Vt
IL
Vo
L
t
+
-
V
o
6. 2) Ideal Current Sources
An ideal current source is a two-terminal element that maintains
the same current regardless of the voltage across its terminals.
IS = constant, no matter what the load voltage is.
IO
VO
IS
7. DEPENDENT (CONTROLLED) SOURCES
Dependent sources are whose output (current or voltage) is a
function of some other voltage or current in a circuit.
The symbols typically used to represent dependent sources are in
the shape of a diamond.
8. BRANCH, NODE, LOOP, MESH
Branch : any portion of a circuit with two terminals
connected to it.
A branch may consist of one or more circuit elements.
9. Node : the point of connection between two or more
branches.
A node usually indicated by a dot in a circuit.
Loop : any closed path through the circuit in which no node
is encountered more than once.
10. Mesh : a loop that does not contain other loops.
11. CURRENT AND KIRCHHOFF’S
CURRENT LAW
Electric Current
Electric current is defined as the time rate of change of
charge passing through a predetermined area.
The units of current are called Amperes, where
1 Ampere (A) = 1 Coulomb/second (C/s).
In order for current to flow, there must exist a closed
circuit.
EEE 1012 INTRODUCTION TO ELECTRICAL ENGINEERING
12. • In the circuit of this figure, the current i flowing
from the battery to the light bulb is equal to the
current flowing from the light bulb to the battery.
no current (and therefore no charge) is “lost”
around the closed circuit. This principle is
known as Kirchhoff’s current law (KCL).
13. Kirchhoff’s Current Law (KCL)
One of the fundamental laws of circuit analysis.
Establish in 1874 by G.R. Kirchhoff.
“The sum of the currents at a node must equal zero.”
𝑛=1
𝑁
𝑖 𝑛 = 0 𝑜𝑟
(𝐸𝑛𝑡𝑒𝑟𝑖𝑛𝑔 𝑐𝑢𝑟𝑟𝑒𝑛𝑡𝑠) = (𝐿𝑒𝑎𝑣𝑖𝑛𝑔 𝑐𝑢𝑟𝑟𝑒𝑛𝑡𝑠)
14. Example of Kirchhoff’s current law:
At node 1:
−𝑖 + 𝑖1 + 𝑖2 + 𝑖3 = 0
𝑖 = 𝑖1 + 𝑖2 + 𝑖3
In this illustration, currents
entering a node are defined as
negative and currents leaving
the node as positive.
15. VOLTAGE AND KIRCHHOFF’S
VOLTAGE LAW
Voltage
The total work per unit charge associated with
the motion of charge between two points.
The units of voltage are called Volts, where
1 Volts (V) = 1 Joule (J)/Coulomb (C).
16. Kirchhoff’s Voltage Law (KVL)
The second fundamental laws of circuit analysis
introduced by G.R. Kirchhoff.
The principle underlying KVL is that no energy is lost or
created in an electric circuit.
In circuit terms, the sum of all voltages associated with
source must equal the sum of the load voltages.
“The net voltage around a closed circuit is zero.”
𝑛=1
𝑁
𝑣 𝑛 = 0
17. Example of Kirchhoff’s voltage law:
𝑣1 = 𝑣2 where
𝑣2 = 𝑣 𝑎𝑏 = 𝑣 𝑎 − 𝑣 𝑏
In general, elements that provide
energy are referred as sources
and elements that dissipate energy
as loads.
18. ELECTRIC POWER
Power
The electric power generated by an active element, or that
dissipated or stored by a passive element, is equal to the
product of the voltage across the element and the current
flowing through it.
The units of power are called Watts (Joules/second).
𝑷 = 𝑽𝑰