Download Electricity/ Electronics I

Electricity/ Electronics I
I. Basic Concepts of Electricity
A. Matter-
B. Physical States of Matter
1.
2.
3.
C. Chemical States of Matter
1. element-
2. compound-
3. mixture-
D. Composition of Matter
1. molecules2. atomsa. electronb. protonc. neutronE. Concept of Electron Theory
1.
2. Valence electrons
3. Ions
F. Energies that change Electrical Balance
1. Friction ex.
2. Chemical energy ex.
3. Mechanical energy ex.
4. Light energy ex.
5. Heat energy ex.
G. Conductors, Semiconductors, and Insulators
1. ___________________________ -have many loosely held valence
electrons (1-3 valence electrons)
2. ___________________________ - materials with properties between
those of conductors and insulators (4 valence electrons)
3. ___________________________ -materials which do not easily allow
electron movement (5-8 valence electrons)
H. An electrical system
1. source
2. conductor
3. control
4. load
I. Static electricity
1.
2.
3.
4.
J. Polarity
1.
2.
K. Coulomb’s Formula
F = force in newtons
Q = charge in coulombs
D = distance in meters
1 coulomb = 6.25 x 1018 electrons
L. Fields of force
M. Electrical potential
1.
2.
3.
II.
Ohm’s law
A. Basic electrical units and abbreviations
term
symbol
units
symbol
B. Using the metric system
(see prefix conversion chart)
C. Electrical shorthand drawings
1. Basic types of drawings
a. Schematic
b. Block diagrams
c. Wiring diagrams
2. _____________________-drawing method for designing circuits,
explaining theory, showing individual components and tracing
current flow.
3. ____________ ______________-used to show a combination of
circuits, better for explaining systems.
4. ________________ _____________-better for replacing
components.
D. Relationships of electrical quantities
1. P = EI
P=
E=
I=
2. E = IR
E=
I=
R=
E. Rearranging to find unknown quantities
(see Algebra I)
F. Sample applications of Metric prefixes and Powers of Ten
(see E&E information, assignment and practice sheets)
G. Some basic rules relating to Powers of ten
(see E&E information, assignment and practice sheets)
H. Direction of Current Flow
1.
2.
3.
I. Polarity and Voltage
1.
2.
3.
J. Work energy and power
K. The resistor color code
(see E&E information, assignment and practice sheets)
III.
Series Circuits
A. Definitions and characteristics of a series circuit
1.
2.
3.
4.
5.
B. Kirchoff’s Voltage Law
1.
2.
3.
C. Power in Series Circuits
1. P = V*I
P = I2*R
P = V2/R
2.
3.
D. Effects of “OPENS” and Troubleshooting Hints
1. Open circuit (definition)-
a. Current flow
b. “Power on”
c. Resistance measurement
2. Hints:
a. Voltage
b. Caution
E. Effects of “Shorts” and Troubleshooting Hints
1. Short circuit (definition)-
2. A short
3. Power
4. Hints:
F. Designing a series circuit to Specifications
(see sample series circuit design problems)
Reference: textbook pages 98-105
G. Special Applications
IV.
Parallel Circuits
A. Definition and Characteristics of a Parallel Circuit
1. Voltage
2. Two or more
3. Branch current
4. As branch resistance increases
B. Voltage in Parallel Circuits
C. Kirchoff’s Current Law
D. Resistance in
E. Power in
F. The Effects of Opens in Parallel Circuits and Troubleshooting Hints
1. Total current flow
2. Total voltage
3. Branch voltage
4. Total power
G. The Effects of Shorts in Parallel Circuits and Troubleshooting Hints
1. Total current flow
2. Total voltage
3. Total circuit resistance
4. Branch voltage
5. Total power
H. Designing a parallel circuit to specifications
(see sample parallel circuit design problems)
Reference: textbook pages 148-149
G. Special applications
V.
Series-Parallel Circuits
A. Definition and Characteristics of Series-Parallel Circuit
1. A circuit
2. There are
3. Parallel components
B. Approaches to recognize and analyze series and parallel circuit portions.
1. Start analysis
2. Trace common current
3. Observe voltages
4. Observe current
5. In the series portion
C. Total resistance in series-parallel circuits using “outside toward the source”
1. Start at the end of circuit
2. First identify and solve
3. Next, work toward the source
4. Applying the reduce-and-redraw approach
D. Current in series-parallel circuits
1. Current distribution through the circuit using Ohm’s Law
2. Kirchoff’s Law
3. Current divider techniques (see practice problem II pg 175)
E. Voltage in series-parallel circuits
1. Ohm’s Law method
2. Resistance and voltage divider techniques (see practice problem III
pg. 178)
F. Power in Series-Parallel Circuits
1. Total power in series-parallel circuits
PT = ET*IT = I2*RT = VT2/RT
2. Total power also equals the sum of all individual power dissipations
3. Individual component power dissipations are calculated using the
individual component parameters.
G. Effects of “Opens” in Series-Parallel Circuits and Troubleshooting Hints
using the circuit below predict what will happen to the following values if R2
is open.
R1
10k
VT
R2
150k
R3
100k
R4
15k
0
Total voltage will ______
Current through R3 will _____
Total current will _____
Voltage across R4 will _____
Voltage across R1 will _____
Current through R4 will _____
Current through R1 will _____
Total power dissipation will _______
Voltage across R2 will _____
Power dissipation by R3 will _____
Current through R2 will _____
Power dissipation by R4 will _____
Voltage across R3 will _____
60 V
H. Effects of shorts in series-parallel circuits and troubleshooting hints
The location of the faulty component
1. A short of any component in
2. A higher than normal current
3. Voltage measurements across
4. Once the shorted portion
IN-PROCESS LEARING CHECK III
1. Refer to figure 5-19. Determine the defective component and the nature of its
defect.
2. Refer to figure 5-20. Indicate which component or components might be suspect
and what the trouble might be.
3. Refer to figure 5-21. Indicate which voltages will change and in which direction if
R2 increases.
Figure 5-19
V
V
D = 50.6V
R6
R5
2.7K
3.3K
C = 16V
R4
V
1.5K
B = 13V
56Vdc
VT
R2
10k
R3
10k
V
A = 3V
R1
1.5k
0
0
V
Figure 5-20
R3
V
47k
121Vdc
B = 121v
A = 17.6v
Vt
R1
27k
0
R2
27k
V
Figure 5-21
R3
V
47k
VT
50Vdc
R1
27k
R2
27k
0
I. Designing a series-parallel circuit to specifications
Practice problem IV- design a series-parallel circuit that meets the following conditions:
Given: six 10KΩ resistors and a 45 volt source, design and draw the circuit diagram
where: V1 = 20v; V2 = 5v; V3 = 5v; V4 = 5v; V5 = 5v; V6 = 20v. Show the current values
and the power dissipation for each of the resistors.
J. Loaded voltage dividers
1. Load
2. Load current
3. RL
4. Ground reference
5. Bleeder current
6. Bleeder resistor
7. Potentiometer
K. Refer to figure 5-31 and answer the following.
1. What is the value of voltage across RL? How much power is
dissipated by RL?
2. What is the value of RL?
3. What is the value of R2?
4. If VRL suddenly decreases due to a change in the R2 value, does this
indicate R2 has increased or decreased in value?
5. If the decrease in VRL in question 4 was caused by a change in R1
value, would it indicate R1 has increased or decreased in value?
6. If RL is disconnected from the voltage divider in the circuit, what is
the new value of VR2?
7. What happens to VRL if R1 opens? If R2 shorts?
Figure 5-31
A
5 mA
R1
200Vdc
10k
V1
R2
RL
2 mA
A
0
L. The Wheatstone Bridge Circuit
1. These circuits include various types of special series-parallel circuits
2. A balanced bridge circuit will occur only when
3. A bridge circuit unlike the illustration is usually drawn in the shape
of a diamond.
Figure 5-32
R1
A
10k
OUTPUT
R2
R3
20K
150Vdc
50k
input
R4
B
100k
OUTPUT
0
M. Using the Wheatstone bridge circuit for measuring unknown resistances
1.
2.
3.
4.
5.
Figure 5-33
R1
A
20k
OUTPUT
R2
R3
20K
150Vdc
input
Rx
B
unknown
0
OUTPUT
VI.
Basic Network Theorems
A. Maximum Power Transfer Theorem
1. Stated
2. Described/Explained
3. Efficiency Factor
4. Note rint. is the symbol used to represent the internal resistance of the
source
5. Calculating internal resisting of the source
B. Super Position theorem
1. Stated
NOTE: The direction of current flow and polarity are very important for each step
2. Circuits solved using this method
3. Using algebraic addition
4. Practice problems see page 218
Practice problems #2
Find
I though R1
V across R1, with Respect to point A
I through R2
V across R2, with respect to point A
I through R3
V with Respect to point A
STEP 1
STEP 2
STEP 3
C. Thevenin’s Theorem
1. Stated
2. Illustrated
B. Use Ohms Law or the Voltage Divider Rule
C. To Find Rth Use Rules of Series and/or Parallel Circuits
4. Thevenin’s Theorem Practice Problem