This document provides an overview of fundamental electrical concepts, including: - The structure of atoms and how they form compounds and matter. - How electrons orbit the nucleus in atoms and the roles of protons, neutrons, and electrons. - The two main types of electrical current used in vehicles. - The six main ways electricity is generated, including chemical action, magnetism, and pressure. - Key electrical terms like voltage, current, resistance, and Ohm's Law. - Common electrical components like transistors, diodes, and test equipment.

1. Welcome to Electrical
Fundamental Electrical
Concepts
Welcome to the world of
smoke and mirrors

2. Visible Matter
 Can be a:
• Solid: Like copper or rubber
• Liquid: Like water or gasoline
• Gas: Like a fart (sometimes a liquid
when you get older…) or hydrogen

3. Visible Matter
 All visible Matter is made up of compounds
 Compounds are made up of atoms
 Atoms are made up of Protons, Electrons and Neutrons

4. What Keeps the Balance?
 Think of the solar system…and how the planets
orbit around the Sun
 Think of the Nucleus as the Sun
 The solar system wants to stay balanced!
 The Nucleus is made up of Neutrons and Protons
Nucleus=
Neutrons
Protons+

5. Hanging Out in Orbit
Nucleus=
Neutrons
Protons+
Electron -
• The Electron hangs out in orbit around the Nucleus
•Since the Electron is – and the Proton is + and the Neutrons just
don’t care…
• Since Likes repel, and Opposites attract…
•The atom is in balance! There is an equal number of Protons
and Electrons.

6. Key Point to Remember
 Like charges repel
 Opposite charges attract
 All Matter has electrical potential

7. Now lets wad up a bunch of copper
atoms to make a wire
The lone electron on the outer valance ring is called a Free
Electron

8. Positive and Negative Ions
When an atom Looses an Electron it is called a Positive Ion.
When an atom gains an electron it is called a Negative Ion.
Attraction…Repulsion…This starts the flow of electricity!

9. Now lets add electricity to the mix!
1 2 3 4
Electricity is the “Flow of Electrons” If you add one
Electron to the first copper atom, it starts a chain
reaction an causes electrical flow…Voltage!
1

10. The 2 main types of electrical
current we use in cars
 AC Alternating current
 DC Direct Current

11. How do we make Electricity?
 Six ways:
• Friction
 Think thunder storms & static electricity
• Pressure
 Think knock sensor-Piezoelectric effect
• Heat
 Think steam or nuclear power
• Light
 Think solar power
• Chemical action
 Think battery
• Magnetism
 Think electric generator

12. Most Common in Vehicles
 Chemical Action (Battery)
 Magnetism (Generator)
 Pressure (Knock Sensor)
 Light (Photo sensor for Headlamps)

13. Electricity by Magnetism
 Magnets have a North and South Pole
 Flowing from N to S are lines of flux
 You can have permanent magnets and
electro magnets
North South

14. Magnetic Induction
 When you pass a coil of wire through
the lines of flux, a voltage is induced
 That induced voltage is the flow of
Electrons
 The direction of the coil or magnet
movement, affects the flow of
electrons

15. 3 things that affect magnetic
induction
1. Strength of the magnetic field
2. The speed in which the conductor
passes through the magnetic field
3. Number of coils in the conductor

16. Chemical Action
 So far, the flow of electrons is
caused by magnetism, pressure, and
light
 No change in the physical matter of
the components has occurred

17. Chemical Action
 In a chemical action:
• The molecules that make up a
substance change by combining or
splitting
• When this happens energy can be
created

18. Chemical Action
 When oxygen atoms react with iron
atoms what happens?
 Rust! The iron turns into iron oxide!

19. Chemical Action
 Now let’s make some voltage
Lemon Style!

20. Insulators and
Conductors

21.  -“Conductors” are atoms with one free
“Electron” loosely bound in a distant valance
ring.
Electrical Basics
Silver Atom

22.  The Free Electron is easily moved
thereby making it an excellent
Conductor !
Electrical Basics
Silver Atom

23. “Insulators” have many “Electrons” in the
outer valance ring and that ring is close to
the center making it hard to move the electrons.
Electrical Basics
Rubber Atom
(not really…)

24. Which is the best conductor?
 Copper
 Silver
 Gold
 Platinum
 Aluminum

25. Relative Resistance
 Silver 1.0
 Copper 1.08
 Gold 1.4
 Aluminum 1.8

26. • If silver is a better conductor than gold,
why do we gold plate terminals in
connectors?

27. Three Basic Elements of
Electricity and Ohm’s Law

28. Voltage

29. Amperage
1 Amp = 6.25x1018 electrons/sec or 625,000,000,000,000,000,000 Electrons

30. Resistance

31. Ohm’s Law

32. E
volts
I
amps
R
ohms
Now let’s keep it simple!

33. E =
“Electro Motive Force”
Pressure (volts)
Voltage is the measurement
of electrical pressure.

34. I=
“Intensity”
Current (amps)
Amperage is the
measurement of
electron flow through a
conductor.

35. R=
“Resistance”
(ohms)
Resistance is the opposition
of electron flow through a
conductor.

36. What things affect resistance?

37. Ohm’s Law
E
I R
Voltage (Volts)
Resistance (Ohms)Current (Amps)
X
÷

38.  When Resistance is high -
How “it” works !

39.  - Current flow is low !
How “it” works !

40. How “it” works !
 This is the “math” !
12
1 12

41. How “it” works !
 Or this is the “math” !
12
2 6

42.  When Resistance is low -
How “it” works !
I
R

43.  - Current is high !
How “it” works !

44. How “it” works !
Again - the “math” !
12
12 1

45. How “it” works !
Or this is the “math” !
12
6 2

46. How “it” works !
In automotive - the “E” usually…
12
6 2

47. How “it” works !
…stays the same
12
6 2

48. How “it” works !
only the R or the I change !
12
6 2

49. How “it” works !
What’s another way to change
the current flow?
12
2 6

50. How “it” works !
Increase the Resistance
12
1 12

51. How “it” works !
Raise the Voltage ?
14
1 14

52. How “it” works !
Lower the Resistance ?
14
2 7

53. All circuits must have:
1. Power source
2. Fuse / Protection
3. Switch
4. Load
5. Conductors

54. Now let’s look at some circuits
 Series Circuit
• The sum of all loads equals total circuit
resistance
• Amperage is constant throughout circuit
• Voltage after the last load should be
close to 0 volts

55. Parallel Circuit
 Total resistance will be lower than
the lowest load resistance
 Amperage is different at each leg of
circuit
 This is the most common circuit used

56. Electrical Test Equipment

57. Test Lights
 Can be used to check for the
presence of power
 CAN’T tell you exact voltage

58. Bubba’s Test Lamp Tips
1. Hook up test lamp to any metal
part on car.
2. Pierce insulation on wire to be
tested.
3. Bright light=12-14 volts
4. Dim light= 11.9-0 volts

59. Analog Meters
 “Old School” volt/ohm meter.
 Uses current it circuit to push needle on
meter.
 Can be used to check for codes on some
manufactures or check duty cycle of the
mixture control solenoids.
 Should Not be used for checking circuits
on today's cars due to it’s low resistance.

60.  What affect do test
lamps and analog
volt/ohm meters
have on computer
circuits?
It causes a increase in
Current flow (AMPS).
And If amperage
increases that means
resistance…..
Decreases

61. Digital Multi Meter
DMM
 The electronic tester of choice.
 Most meters are auto ranging.
 Very high resistance (10 million Ω’s or higher).
 Accurate when testing low voltage circuits.
 Most DMM’s have a setting for testing diodes.
(The DMM sends out a low voltage to test
diodes.)
 Be sure to look for symbol on read out or look at
the scale the meter is set on to determine the
correct scale, i.e.: K, m, M.

62. Logic Probe
 A logic probe is like a test lamp but:
• Has a power and ground lead.
• Uses LED’s to show power and
ground.
• Is computer safe.
• Can be used to check the ground of
ground side switched circuits.

63. What do we use these tools for?
 Testing for:
• Open Circuits
• Shorted Circuits
• Volt Drop Tests

64. Open Circuits
 The path for current flow to ground
has been interrupted.
• Open fuse
• Broken wire
• Cut wire
• Bad switch contacts
• Burnt fuse link

65. Short Circuits
 A connection between two or more
conductors, which may bypass normal
loads.
 Short circuits can be caused by several
things:
• Corrosion (battery acid)
• Liquid such as Coolant, Water or Oil
• Screws in looms
• Pinched looms
• Bad wire insulation (melted, weather cracked
etc.)
 May or may not blow a fuse

66. Grounded Circuits
 A circuit whose path to ground has been
interrupted by a new path to ground that
was not intended. Also called Short to
Ground.
• Wire loom damage-Pinched, Chaffed or screws
in looms
• Shorted switches
• Bad sensors shorting reference voltage to
ground

67. Short to Ground

68. Diagnosing
Intermittent Electrical Problems
 They can be a real bugger.
1. Ask yourself the “Three W’s”
– What happened
– When does it happen
– Where does it happen
2. Study the wiring diagram to see what
the possible sources of the concern
may be, open circuit, short to ground,
short to power.
3. Try to isolate the possible circuits.

69. Diagnosing a Short Circuit
1. See what circuits are affected.
2. Study wiring diagram and look for
common connectors, grounds,
power sources, and loom routing.
3. Try to isolate individual branches in
circuit.
4. A Good visual inspection is very
important.

72. Transistors
Base
Emitter
Collector
Base
Collector
Emitter
PNP Transistor NPN Transistor

73. Transistors
 Transistors have no moving parts so
in theory they don’t wear out like
relays.
 They are small.
 They have the ability to switch very
fast. A relay can’t due to mechanical
moving parts.
 The max voltage drop across a
transistor is .60V.

82. Diodes
 Diodes work like a one-way valve.
 They let voltage travel in only one
direction in a circuit.
 Diodes are used in alternators to rectify
A/C current to D/C current.
 Diodes are used to prevent voltage spikes
back to the PCM from solenoid type
actuators.
 The max voltage drop across a diode is
.6V.