Download Slide - ICT@UP

305221, 226231
Computer Electrical Circuit
Analysis
การวิเคราะห ์วงจรไฟฟ้าทาง
คอมพิวเตอร ์
3(2-3-6)
ณรงค์ชยั
มุ่งแฝงกลาง
คมกริ ช มาเที่ยง
สัปดาห์ที่ 3
Ohm’s law and Kirchhoff's laws
Outline
1
Objectives
2
Kirchhoff’s Current Law
3
Kirchhoff’s Voltage Law
4
Voltage & Current Division
5
Assignments
Objectives
 เพื่อให้ นิสิตมีความรู้ ความเข้ าใจเกีย่ วกับ Kirchhoff’s current
Law
 เพื่ อให้นิ สิ ต มี ค วามรู ค
้ วามเข้า ใจเกี่ยวกับ
Kirchhoff’s Voltage Law
 เพื่อให้ นิสิตมีความรู้ ความเข้ าใจเกีย่ วกับ Voltage และ Current
Division
Branch
 Matthew Sadiku, define A
branch represents a single
element such as a voltage source or a resistor.
 William Hayt, define a branch as a single path in a network,
composed of one simple element and the node at each end of
that element.
Node
Matthew Sadiku, a node is the point of connection
between two or more branches.
William Hayt, a point at which two or more elements
have a common connection is called “a node”.
=
Path & Loop
 William Hayt, The set of nodes and elements that
we have passed through is defined as “a path”.
 Matthew Sadiku, A loop is any closed path in a
circuit.
William Hayt, If the node at which we started is the
same as the node on which we ended, then the path
is, by definition, a closed path or “a loop”.
Branches, Nodes, Path and Loops
=
Outline
1
Objectives
2
Kirchhoff’s Current Law
3
Kirchhoff’s Voltage Law
4
Voltage & Current Division
5
Assignments
Kirchhoff’s Current Law
 Kirchhoff’s current law (KCL) states that “the
algebraic sum of currents entering a node (or a
closed boundary) is zero”.
KCL Example
Outline
1
Objectives
2
Kirchhoff’s Current Law
3
Kirchhoff’s Voltage Law
4
Voltage & Current Division
5
Assignments
Kirchhoff’s Voltage Law
Kirchhoff’s voltage law (KVL) states “that the
algebraic sum of all volt-ages around a closed path
(or loop) is zero”.
Determine ix and vx ?
Determine ix and vx ?
Determine vR2 and v2 ?
Determine vx in the circuit ?
Determine vx in the circuit ?
Determine i and vo ?
Find currents and voltages in the circuit ?
Outline
1
Objectives
2
Kirchhoff’s Current Law
3
Kirchhoff’s Voltage Law
4
Voltage Division
5
Assignments
Series Resistors and Voltage Division
Equivalent of Series Resistors
 The equivalent resistance of any number of resistors
connected in series is the sum of the individual resistances.
Voltage Division
Outline
1
Objectives
2
Kirchhoff’s Current Law
3
Kirchhoff’s Voltage Law
4
Current Division
5
Assignments
Parallel Resistors
The equivalent resistance of two parallel resistors is
equal to the product of their resistances divided by their
sum.
Equivalent Conductances
 The equivalent conductance of resistors connected
in parallel is the sum of their individual conductances.
Current Division
Outline
1
Objectives
2
Kirchhoff’s Current Law
3
Kirchhoff’s Voltage Law
4
Voltage & Current Division
5
Assignments
Assignment # 1
In the circuit shown in Fig. 3.51, the resistor values
are unknown, but the 2 V, source is known to be
supplying a current of 7 A to the rest of the circuit.
Calculate the current labeled i2.
Assignment # 2
The voltage source in the circuit of Fig. 3.52 has a
current of 1 A flowing out of its positive terminal into
resistor R1. Calculate the current labeled i2.
Assignment # 3
Referring to the circuit of Fig. 3.69, (a) determine
the two currents i1 and i2; (b) compute the power
absorbed by each element.
Assignment # 4
Determine a value for the voltage v as labeled in the
circuit of Fig. 3.70, and compute the power supplied
by the two current sources.
Assignment # 5
For the circuit presented in Fig. 3.75, determine the
current labeled i by first combining the four sources
into a single equivalent source.
Assignment # 6
Obtain v1 through v3 in the circuit of Fig. 2.81.
Assignment # 7
Find I and Vab in the circuit of Fig. 2.82.
Assignment # 8
Determine io in the circuit of Fig. 2.84.
Assignment # 9
Find Vx in the circuit of Fig. 2.85.
Assignment # 10
Find Vo in the circuit of Fig. 2.86 and the power
dissipated by the controlled source.