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Syllabus
• 이론강의 + 실험
• 주교재– 전기전자공학개론, Giorgio Rizzoni (송재복 외 역), McGraw-Hill Korea, 5판
• 부교재– 전기전자공학의 길라잡이, 신윤기, GS인터비젼, 2014년– 기초전기전자공학, T. L. Floyd, D. M. Buchla (손상희 외 역), 시그마프레스, 8판
• 성적– 이론강의 수업태도(출석, 숙제 등 10%) + 중간고사(30%) + 기말고사(25%) + 실험보고서(20%) +
Term project (15%)– 실험 출석 별도– 교수별 분반 합산하여 성적 산출
주 이론강의 실험 참고1 저항회로망 해석 전원공급기/디지털 멀티미터
2 추석연휴
3 등가회로 등가회로/중첩의 원리/최대전력전달
4 선형회로 시간응답 함수발생기/오실로스코프
5 선형회로 주파수응답 RLC회로
6 다이오드 및 정류회로 다이오드/광소자/정류회로
7 트랜지스터 트랜지스터 특성실험
8 중간고사
9 연산증폭기 원리 연산증폭기 특성실험
10 연산증폭기 응용 연산증폭기 응용실험 Term project 구상
11 디지털 논리회로 디지털 논리회로 실험 부품신청
12 조합/순차논리회로 플립플롭/카운터
13 Term project 수행
14 Term project 수행
15 Term project 발표
16 기말고사
DC CIRCUITS
Ho Kyung Kim, [email protected]
School of Mechanical EngineeringPusan National University
Basic Experiment and Design of Electronics
Outline
• Definition
• Serial vs. parallel circuits with resistances
• Kirchhoff’s law
• Voltage divider
• Loading effect
• Measuring devices
• Circuit analysis
Analogy btwn fluid & electricity
v
q R
i
Ground
h
Q
Q
R
Ground
• Charge: fundamental electronic quantity– elementary charges: electron, proton– electronic charge, q = 1.602 10-19 C
• Current: C/s or A
• Voltage or potential difference: 1 V = 1 J/C
• Ground: earth ground/chassis ground
• Power: J/s or W
• Source (energy generation) vs. load (energy dissipation)– battery vs. a light bulb
Definition
dtdqi
CurrentVoltageTime
ChargeChargeWork
TimeWorkPower
RVRIVIP
22
• Circuit or network• Source
– voltage– current: DC vs. AC
• Branch• Node• Loop Mesh
• Network analysis– to determine a specific voltage, current, or power somewhere in a network
• Resistance: constant of proportionality between the voltage and current• Ohm's law
Resistor
A
l
v
iv
1/Ri
RIV
Al
Al
IVR
= resistivity [cm]
= 1/ = conductivity [(cm)-1 or S/cm]
– Electron drift velocity
– Current
– Conductance
lVEv eee
VlAV
lAqn
lVAqnnvqAI eee )(
RG 1 [S or mho] GVI
– Algebraic sum of the currents leaving a node is zero
– Sum of currents entering node is equal to the sum of the currents leaving the node
– Charge conservation law
• Algebraic sum of the currents entering any node is zero;
KCL: Kirchhoff's current law
0)(1
N
jj ti
i1(t)
i5(t)
i4(t)
i3(t)
i2(t)
0)()()()()( 54321 tititititi
0)()()()()( 54321 tititititi
)()()()()( 43251 tititititi
• Algebraic sum of the voltages around any loop is zero;
– energy conservation law
KVL: Kirchhoff's voltage law
0)(1
N
jj tv
+–
+ -+
-+-
SV
1RV
2RV
3RV
0321 RRRS VVVV
• Series circuit– Two or more circuit elements are said to be in series if the current from one element exclusively
flows into the next element– From KCL, it then follows that all series elements have the same current
• Parallel circuit– Two or more circuit elements are said to be in parallel if the elements share the same terminals– From KVL, it follows that the parallel elements will have the same voltage
Series vs. parallel circuits
Series circuit
–+
+–
+ –
– +
–+
+ -
)(1 tv
1Rv
2Rv
1R
+
-2R)(5 tv
)(2 tv
)(3 tv
)(4 tv
)(ti
0)()()()()()()( 1542321 tvtvtvtiRtvtvtiR
)()()()()()( 5432121 tvtvtvtvtvtiRR
+–)(tv
1R
2R
)(ti
≡ v(t)
sum of several voltage sources in series can be replaced by one sourcewhose value is the algebraic sum of the individual sources
+–)(tv SR
)(ti
≡ RS
equivalent resistance of N resistors in seriesis simply the sum of the individual resistances
N
jjS RR
1
Parallel circuit
1R 2R)(1 ti↑ ↓ ↑ ↓)(tv+
-)(3 ti )(4 ti )(6 ti
)(2 ti )(5 ti
0)()()()()()( 654321 titititititi
)()()()()()( 526431 titititititi
↑)(0 ti 1R 2R )(tv+
-
sum of several current sources in parallel can be replaced by one source whose value is the algebraic sum of the individual sources
≡ i0(t))(11
21
tvRR
↑ PR)(0 ti )(tv+
-
N
j jP RR 1
11
PRtv )(
Voltage divider
+
-)(tv
1Rv
2Rv
1R
+– +
-2R
)(ti KVL; 0)( 21 RR vvtv
21)( RR vvtv
Ohm's law; )(11 tiRvR
)(22 tiRvR
Therefore,
)()()( 21 tiRtiRtv
21
)()(RR
tvti
)()(21
111 tv
RRR
tiRvR
)()(21
222 tv
RRR
tiRvR
v(t) is divided between R1 and R2 in direct proportion to their resistances; voltage divider
• Voltage divider: the voltage across each resistor in a series circuit is directly proportional to the ratio of its resistance to the total resistance of the circuit
Divider rules
• Current divider: the current in a parallel circuit divides in inverse proportion to the resistances of the individual parallel elements
SNn
nn i
RRRRR
i/1/1/1/1
/1
21
SNn
nn v
RRRRR
v
21
Loading effect
+–Vin = 30 V
R1 = 10 k
R2 = 10 k
Vout = ?
Vin
R1
R2
Vout
R3
Vin
R1
R2 R3
Vin
R1
R2 || R3
Vout
• Ammeter– current measuring device– connected in series for the same current– zero internal resistance required
• Voltmeter– voltage measuring device– connected in parallel for the same voltage– infinite internal resistance required
• Ohmmeter– resistance measuring device– connected and functioned when the element is disconnected from any other circuit
Ohmmeter
Measuring devices
R
Ammeter
Voltmeter
Open and short circuits
V
+
-
I
V
+
-
I
I = 0 for any VR =
V = 0 for any IR = 0
• Or network analysis• To determine a specific voltage, current, or power somewhere in a network
• Two methods– Nodal analysis = node voltage method– Loop analysis = mesh current method
Circuit analysis
Nodal analysis
• or node voltage method
① select a reference node (usually ground)② define n – 1 node voltages③ determine branch currents using Ohm's law④ apply KCL at each node⑤ solve the linear system
– n – 1 – m unknowns if m voltage sources
① select a reference node② define n – 1 node voltages
111 R
vR
vvi aca
22 R
vvi ba
333 R
vR
vvi bcb
③ determine branch currents
④ apply KCL at each node
⑤ solve the linear system
021 iiiS 032 ii
Sba ivR
vRR
221
111 0111
322
ba v
RRv
R
• or mesh current method
① define each mesh current consistently– e.g., clockwise direction
② apply KVL at each mesh③ solve the linear system
– n – m unknowns if m current sources
Loop analysis
① define each mesh current
② apply KVL at each mesh
③ solve the linear system
0)( 22111 RiiRivS
0)( 4232212 RiRiRii
SviRiRR 22121 )(
0)( 243212 iRRRiR
Self-assigned HW
• Rizzoni (5th ed.), Ch. 3– 1, 2, 3, 4, 7, 8, 9, 10, 11, 12
