Basic DC Circuits

1
Chapter 1

• Basic DC Circuits

2
Objectives

• Distinguish between dc and ac and discuss some of
  the basic properties of each.
• State and describe the basic circuit variables
  including charge, voltage, current, power, and
  energy.
• Define resistance and conductance and show the
  schematic symbol.

3
Objectives

• State the properties of the ideal voltage source
  and ideal current source models and show their
  schematic symbols.
• State and apply Ohms law.
• Discuss voltage and current measurements and how
  they are made.
• State and apply Kirchoffs voltage law.
• State and apply Kirchoffs current law.

4
Objectives

• Determine equivalent resistance using series and
  parallel combinations.
• Analyze a single-loop (series) circuit to
  determine all the variables.
• Analyze a single node-pair (parallel) circuit to
  determine all the variables.
• State and apply the voltage divider rule.
• State and apply the current divider rule.

5
1-1 DC Circuit Variables
6
Comparison of a DC Voltage and an AC Voltage
7
Conventional Current Flow in Opposite Direction
to Electron Flow
8
Voltage Between Two Points in a Circuit
9
Schematic Symbols for an Ideal Voltage Source and
a Battery
10
Schematic Symbol for an Ideal Current Source
11
Schematic Symbol for a Resistance
12
Illustration of a Short Circuit and an Open
Circuit
13
1-2 A Very Simple DC Circuit
14
Simple Circuit Used to Illustrate Ohms Law
15
Different Types of Ground
16
Simple Circuit Redrawn with Ground Symbols
17
1-3 Measuring DC Circuit Variables
18
A Voltmeter is Connected Between Two Points in a
Circuit Across Which the Voltage is to be Measured
19
An Ammeter is Connected Within the Branch for
Which Current is to be Measured
20
1-4 Power and Energy
21
Reference Directions for Power Delivered
22
Reference Directions for Power Absorbed
23
1-5 Kirchoffs Laws
24
A Loop Used to Illustrate Kirchoffs Voltage Law
25
Illustration of Kirchoffs Current Law at a Node
26
Circuit of Example 1-8
27
Circuit of Example 1-9
28
1-6 Equivalent Resistance
29
Resistances in Series and the Equivalent Single
Resistance
30
Resistances in Parallel and the Equivalent Single
Resistance
31
Circuit of Example 1-10
32
Reduction of the Circuit of Example 1-10
33
1-7 Single-Loop or Series Circuit
34
Representative Single-Loop (Series) Circuit
35
Circuit of Example 1-11
36
Circuit of Example 1-12
37
1-8 Single Node-Pair or Parallel Circuit
38
Single Node-Pair (Parallel) Circuit
39
Representative Parallel Circuit with Current
Sources
40
Circuit of Example 1-13
41
Circuit of Example 1-14
42
1-9 Voltage and Current Divider Rules
43
Circuit Used to Illustrate the Voltage Divider
Rule
44
Circuit Used to Illustrate the Current Divider
Rule
45
Circuit of Example 1-15
46
Circuit of Example 1-16