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LESSON 1 – HOW DOES ELECTRICITY WORK?. BASIC DC ELECTRICITY. Hydraulic system OIL Fuel System FUEL Electrical System? Electrons. WHAT IS OUR FLUID?. WHERE DO ELECTRONS COME FROM?. Electrons come from ATOMS Atoms have two main parts Nucleus Protons (+ charge) Neutrons (no charge)

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What is our fluid

WHAT IS OUR FLUID?


Where do electrons come from
WHERE DO ELECTRONS COME FROM?

  • Electrons come from ATOMS

  • Atoms have two main parts

    • Nucleus

      • Protons (+ charge)

      • Neutrons (no charge)

    • Electrons (- charge) in orbit around the nucleus


Electrons
ELECTRONS

  • The electrons in the outermost orbit of the atom are called VALENCE electrons

  • During electricity, or electrical flow, our “fluid” will be the VALENCE ELECTRONS that migrate from one atom to another

  • The inner electrons are magnetically bonded to the nucleus and therefore cannot move

  • The valence electrons have a weak bond that is easily broken to allow movement (flow)


Different matter different atoms
DIFFERENT MATTER = DIFFERENT ATOMS

Oxygen

Chlorine

Titanium

Silicon


Conductors

CONDUCTORS

Copper (1)

Silver (1)

Iron (2)

Aluminum (3)


Insulators

Inhibit electron flow (requires much more force)

Have more than four valence electrons

INSULATORS

Argon (8)

Nitrogen (5)

Iodine (7)

Sulfur (6)


Semi conductors

Have EXACTLY four valence electrons

SEMI-CONDUCTORS

Carbon

Silicon

Germanium


Semi conductors1

Can be used as either a conductor or insulator depending on the application

Diodes are primarily made up of semi-conductors

SEMI-CONDUCTORS

No Flow

Flow


Electrical wire

  • Usually made up of copper strands the application

    • Can also be other conducting material (aluminum, titanium, steel, etc.)

  • Each strand contains billions of atoms

  • Electricity is the flow of electrons from one atom to another atom in a conductor

ELECTRICAL WIRE


Video
VIDEO the application

If the video does not automatically start by itself, do one of the two suggestions below.

Click on the direct link to the video. Click here

Go to www.youtube.com, copy / paste this code into the search box vL2KklctxQ0, and click on the video link that pops up.


Knowledge check

Return to the course material listed in the the applicationLESSON 1 folder and click on the link labeled “Knowledge Check 1”

This quiz will not be counted towards your final course grade but will provide valuable feedback before you move on

After completing the knowledge check, return to this lesson and resume at slide #13

KNOWLEDGE CHECK


Basic parts of a circuit
BASIC PARTS OF A CIRCUIT the application

+ -

  • Power source

    • Battery

    • Generator

    • Alternator

  • Provides a potential difference in magnetic charges between the two sides of the power source

  • Often called the VOLTAGE SUPPLY


Basic parts of a circuit1
BASIC PARTS OF A CIRCUIT the application

  • Conductor

    • Provides a path for electrons to travel between the positive and negative charged sides of the source


Basic parts of a circuit2
BASIC PARTS OF A CIRCUIT the application

load

  • Load

    • Whatever electrical component you are trying to get work or power out of

      • Light bulb

      • Electrical motor

      • Solenoid valve

    • Provides resistance in the circuit which limits how many electrons can flow

    • Unlimited electron flow, or no resistance or no load, is bad

      • Balances the magnetic difference in the source (making it useless)

      • Creates tremendous heat from billions of electrons colliding with each other

      • Is dangerous because it can cause sparks and fire

load


Short circuiting

What happens when electrons are allowed to flow unlimited from one end of the source to the other

Short circuiting

If the video does not automatically start by itself, do one of the two suggestions below.

Click on the direct link to the video. Click here

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Basic circuit symbols
BASIC CIRCUIT SYMBOLS from one end of the source to the other

+

Wire (conductor)

-

Battery (source)

Resistance (load)


Basic circuit diagram
BASIC CIRCUIT DIAGRAM from one end of the source to the other

+

-



Ground

Refers to the conducting side between the load and the - charge of the source

GROUND

+

-

Ground


Why do we call it ground
WHY DO WE CALL IT “GROUND”? charge of the source

  • In A/C electricity (alternating current), like in your home or on a farm, the actual earth (ground) plays a role in how the “return” side of the system works


Why do we call it ground1
WHY DO WE CALL IT “GROUND”? charge of the source

  • The term has carried over to D/C electricity (direct current) and is used more as slang or jargon.

  • The earth plays no role at all in DC electricity

  • We say “ground” to simply identify the return side of the system


Why do we call it ground2
WHY DO WE CALL IT “GROUND”? charge of the source

  • There are similarities

    • The ground in AC uses the earth as a return conductor instead of a wire

    • The ground in DC often uses the iron frame of the machine as a return conductor instead of a wire


Why do we call it ground3
WHY DO WE CALL IT “GROUND”? charge of the source

  • There are similarities

    • The ground in AC uses the earth as a return conductor instead of a wire

    • The ground in DC often uses the iron frame of the machine as a return conductor instead of a wire

Iron frame of machine

Load

Load

Load

Circuit “ground” point


Control

control

+

-


Control1

control

+

-


Control2

control

+

-


Closed circuit

CLOSED CIRCUIT

+

-


Open circuit

OPEN CIRCUIT

+

-


Open circuit1

The magnetic charged particles are still present. They just can’t flow

OPEN CIRCUIT

+

+

+

+

+

+

+

+

-

-

-

-

+

+

+


Which way does it flow

  • This diagram shows can’t flowConventional Flow Theory

    • Electrical flow starts at the positive terminal of the source and flows through the system returning to the source at the negative terminal

WHICH WAY DOES IT FLOW?

+

-


Which way does it flow1

  • This diagram shows can’t flowElectron Flow Theory

    • Electrical flow starts at the negative terminal of the source and flows through the system returning to the source at the positive terminal

WHICH WAY DOES IT FLOW?

+

-


Which way is correct

  • Technically? can’t flow

    • Electron Flow Theory

      • Electrons are negative charged particles and therefore should REPEL away from the negative terminal and ATTRACT towards the positive terminal

Which way is correct?

+

-


Which way is correct1

  • Realistically for troubleshooting? can’t flow

    • Conventional Flow Theory

      • Our primary tool for troubleshooting is a voltmeter

      • Voltmeters measure the difference in magnetic charge between two points in the system, often times referred to as the charge “gap”

      • The GAP direction is opposite the direction of the electrons

Which way is correct?

+

12.52 V

-


Gap theory
GAP THEORY can’t flow

  • Why it makes sense to troubleshoot electrical systems from positive to negative (conventional flow), even though the electrons flow from negative to positive

If the video does not automatically start by itself, do one of the two suggestions below.

Click on the direct link to the video. Click here

Go to www.youtube.com, copy / paste this code into the search box 5igHrRV16uk and click on the video link that pops up.


Knowledge check1

Return to the course material listed in the can’t flowLESSON 1 folder and click on the link labeled “Knowledge Check 2”

This quiz will not be counted towards your final course grade but will provide valuable feedback before you move on

After completing the knowledge check, return to this lesson and resume at slide #37

KNOWLEDGE CHECK


Lesson wrap up

At this point you should be able to describe the “fluid” used in electrical systems, identify materials that make good conductors, good insulators, and good semi-conductors, and describe the path of electron flow through a complete circuit.

You will soon take a lesson assessment that will be scored and recorded. You must achieve a minimum of 80% for each lesson in this course to receive credit.

Are you ready?

LESSON wrap up


Lesson wrap up1

One last review before the test used in electrical systems, identify materials that make good conductors, good insulators, and good semi-conductors, and describe the path of electron flow through a complete circuit.

LESSON wrap up

If the video does not automatically start by itself, do one of the two suggestions below.

Click on the direct link to the video. Click here

Go to www.youtube.com, copy / paste this code into the search box D2monVkCkX4 and click on the video link that pops up. The video is over 8 minutes long but only the first 5:00 minutes is relevant for this lesson.


Additional resources

The links on the next page will take you to various web sites and videos with related information. You are not required to study them but may find them helpful if you are unsure about anything or just want more information.

Additional resources


Additional resources1

http://science.howstuffworks.com/electricity2.htm sites and videos with related information. You are not required to study them but may find them helpful if you are unsure about anything or just want more information.

http://www.energyquest.ca.gov/story/chapter02.html

http://www.qrg.northwestern.edu/projects/vss/docs/power/2-whats-electron-flow.html

http://www.youtube.com/watch?v=EJeAuQ7pkpc

http://www.youtube.com/watch?v=jbi7gJTPSXk

http://www.youtube.com/watch?v=vL2KklctxQ0

http://science.howstuffworks.com/environmental/energy/circuit2.htm

http://www.allaboutcircuits.com/vol_1/chpt_1/5.html

http://www.allaboutcircuits.com/videos/16.html

http://www.youtube.com/watch?v=ymRwIUNlEL4

http://www.engineeringinteract.org/resources/siliconspies/flash/concepts/buildingcircuits.htm

http://tymkrs.tumblr.com/post/5513058883/conventional-flow-vs-electron-flow-theory

http://www.allaboutcircuits.com/vol_1/chpt_1/7.html

http://www.rare-earth-magnets.com/t-conventional-vs-electron-flow.aspx

http://www.youtube.com/watch?v=5igHrRV16uk

Additional resources


Lesson assessment

Return to the Lesson 1 folder and click on the link labeled “Lesson 1 Assessment.”

It is required to have a minimum score of 80% for all lesson assessments to receive credit for completing this course.

You may take the assessment as many times as needed to achieve a minimum score of 80%

LESSON ASSESSMENT


Image and video attributions

AhmadSherif “Lesson 1 Assessment.” (Own work) [Public domain], via Wikimedia Commons

Andy Dingley (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Djanes (Own work) [Public domain], via Wikimedia Commons

Greg Robson) [CC-BY-SA-2.0-uk (http://creativecommons.org/licenses/by-sa/2.0/uk/deed.en)], via Wikimedia Commons

Hight, S. (2012). Electron flow vs conventional current[Web]. Retrieved from http://www.youtube.com/watch?v=5igHrRV16uk

Quarked Project. (2011). How electrons become electricity [Web]. Retrieved from http://www.youtube.com/watch?v=vL2KklctxQ0

Robinsonsauto. (2012). Having fun with fuses (short circuit)[Web]. Retrieved from http://www.youtube.com/watch?v=V-lhVTDWjwY

Science Online. (2008). Electricity and circuits [Web]. Retrieved from http://www.youtube.com/watch?v=D2monVkCkX4

Scott Ehardt (Own work) [Public domain], via Wikimedia Commons

Scratch (http://wiki.scratch.mit.edu/wiki/Category:Images) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0) or CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

StromBer 16:51, 17. Dez. 2007 (CET).StromBer at de.wikipedia [CC-BY-SA-2.0-de (http://creativecommons.org/licenses/by-sa/2.0/de/deed.en)], from Wikimedia Commons

wdwd (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Image and video attributions


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