7260243 electrical fundamentals

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Electrical Fundamentals

MATTER

Everything in the world is made of matter.Matter is anything that has mass (weight) andoccupies space.

Matter can be made up of a group or series of

different atoms to form a molecule. Thesegroups of atoms (molecules) are sometimescalled compounds. Some types of matter canbe broken down to a single atom while stillmaintaining the properties of the original

material. These types of material are calledelements.

Matter has three states: Solid, Liquid, andVapor.

MOLECULE EXAMPLE

Imagine a lake. Nowimagine taking the

smallest particle orpiece of water fromthe lake. You wouldhave a singlemolecule of water,

H2O, which is madeup of two hydrogenatoms and oneoxygen atom.

MOLECULE EXAMPLE

Not all materials aremade up of

molecules. Copper,for example, is madeup of a single copperatom. These arecalled elements. Each

element is a type of matter that hascertain individualcharacteristics.

THE ATOM

One of the basicbuilding blocks in theuniverse for matteris the atom. Allmatter - gas, liquid,

or solid - is made upof molecules oratoms joinedtogether. Theseatoms are the

smallest particle intowhich an element orsubstance can bedivided withoutlosing its property.

THE ATOM A single atom

consists of three

basiccomponents: aproton, aneutron, and an

electron.

THE ATOM Within the atom

there is a

Nucleus. TheNucleus containsthe protons andneutrons. Orbiting

around thenucleus are theelectrons.

THE ATOM An atom is similar to

a miniature solarsystem. As with the

sun in the center of the universe, thenucleus is in thecenter of the atom.Protons and

Neutrons arecontained inside thenucleus. Orbitingaround the nucleusare the electrons.

ATOM CONSTRUCTION

An atom is similar to aminiature solar system.As the sun is in the centerof the solar system, so is

the nucleus is in thecenter of the atom.Protons and neutrons arecontained within thenucleus. Electrons orbit

around the nucleus,which would be similar toplanets orbiting aroundthe sun.

NUCLEUS

The Nucleus islocated in the center

of the atom (shownin red).

The Nucleus containsthe protons andneutrons.

Orbiting around thenucleus are theelectrons.

PROTONS

Protons arelocated within the

nucleus of theatom (shown inblue).

Protons are

positively (+)charged.

NEUTRONS

Neutrons addatomic weight to

an atom (shownin green).

Neutrons have noelectrical charge.

ELECTRONS

Electrons orbitaround the

nucleus of theatom (shown inyellow).

Electrons are

negatively (-)charged.

ELECTRONS

Since electrons arelighter than protonsand are outside the

nucleus, they can beeasily moved fromatom to atom toform electrons.Normally electrons

are prevented frombeing pulled into theatom by the forwardmomentum of theirrotation.

ELECTRONS

Electrons are alsoprevented from

flying away becauseof the magneticattraction of theprotons inside thenucleus, the same

type of force thatkeeps the planetsorbiting around thesun.

ELECTRICAL CHARGES

Opposite electrical charges always attracteach other. So these particles with opposite

charges will tend to move toward each other.Like electrical charges always repel. Soparticles with like charges will move awayfrom each other.

Remember: Opposites charges attract, andlike charges repel.

Atoms always try to remain electricallybalanced.

BALANCED ATOMS

Atoms normally have an equalnumber of electrons and protons.

Atoms have no electrical charge.They are neither positive nor

negative. They are electrically neutralor BALANCED.

BALANCED ATOMS

The negative charge of the electrons

will cancel the positive charge of theprotons, thus balancing the charge of the atom.

This cancellation of charges creates a

natural attraction or bonding betweenthe positive proton and the negativeelectron.

ION PARTICLES When an atom

loses or gains an

electron, animbalance occurs.

The atombecomes either a

positively ornegativelycharged particlecalled an ION.

ION PARTICLES These unbalanced

charged ION

particles areresponsible forelectron flow(electricity).

IONs will take orrelease anelectron tobecome balancedagain.

ION CHARGE A positive (+)

ION has one less

electron than ithas protons.

A negative (-)ION has one more

electron than ithas protons.

ION CHARGE The positive ION

attracts a

negative ION tobecome balanced.This attraction ordifference in

electrical potentialcauses electronflow.

ELECTRON OR BITS Electrons rotate around

the atom at differentorbits called Rings, Orbits,or Shells.

BOUND ELECTRONS orbitthe nucleus on the innerrings. Bound electronshave a strong magneticattraction to the nucleus.

FREE ELECTRONS orbit onthe outermost ring whichis known as the VALANCERING.

FREE ELECTRONS

Only the FREEELECTRONS in theoutermost shell

(Valance Ring) are freeto move from atom toatom. This movement iscalled ELECTRON FLOW.

These FREE ELECTRONS

are loosely held and caneasily be moved toanother atom or ion.

FREE ELECTRONS

Because of theirdistance from thenucleus, free electrons

have a weak magneticattraction. Since thisattraction is not asstrong to the nucleus asthe bound electrons on

the inner orbits, theelectrons move easilyfrom atom to atom.

INSULATORS An INSULATOR is

any material that

inhibits (stops) theflow of electrons(electricity).

An insulator is any

material with 5 to8 free electrons inthe outer ring.

INSULATORS Because, atoms with 5

to 8 electrons in theouter ring are held

(bound) tightly to theatom, they CANNOT beeasily moved to anotheratom nor make room formore electrons.

Insulator materialincludes glass, rubber,and plastic.

CONDUCTORS A CONDUCTOR is

any material that

easily allowselectrons(electricity) toflow.

A CONDUCTORhas 1 to 3 freeelectrons in theouter ring.

CONDUCTORS Because atoms with

1 to 3 electrons inthe outer ring are

held (bound) looselyto the atom, theycan easily move toanother atom ormake room for more

electrons. Conductor material

includes copper andgold.

SEMICONDUCTORS Any material with

exactly 4 free

flectrons in theouter orbit arecalledSEMICONDUCTORS.

A semiconductor isneither a conductoror insulator.

SEMICONDUCTORS semiconductor

material includes

carbon, silicon,and germanium.

These materialsare used in themanufacturer of diodes,transistors, andintegrated circuitchips.

ELECTRON THEOR The Electron Theory states that

current flows from NEGATIVE to

POSITIVE. Electrons move fromatom to atom as they move throughthe conductor towards positive.

CONVENTIONAL

THEORY Conventional theory, also known as HOLE

THEORY, states that current flows from POSITIVEto NEGATIVE. Protons or the lack of electrons (the

holes) move towards the negative. (Current flowdirection in Hole Theory is the opposite of that inElectron Theory.)

VOLTAGE Voltage is the electrical force that

moves electrons through a conductor.

Voltage is electrical pressure alsoknown as EMF (Electro Motive Force)that pushes electrons.

VOLTAGE The greater the difference in electrical

potential push (difference between

positive and negative), the greater thevoltage force potential.

MEASUREMENT A VOLTMETER

measures thevoltage potential

across or parallel tothe circuit.

The Voltmetermeasures theamount of electrical

pressure differencebetween two pointsbeing measured.

MEASUREMENT Voltage can exist

between two

points withoutelectron flow.

VOLTAGE UNITS Voltage is measured in units calledVOLTS.

Voltage measurements can use different

value prefixes such as millivolt, volt,Kilovolt, and Megavolt.

VOLTAGE LESS THANBASE UNIT

BASIC UNIT LARGER THANBASE UNIT

Symbol mV V kV

Pronounced millivolt Volt Kilovolt

Multiplier 0.001 1 1,000

CURRENT (AMPERES)

CURRENT is the quantity or flow rate of electrons moving past a point within onesecond. Current flow is also known as

amperage, or amps for short. Higher voltage will produce higher current

flow, and lower voltage will produce lowercurrent flow.

MEASUREMENT An AMMETER measures the quantity of

current flow. Ammeters are placed in

series (inline) to count the electronspassing through it.

Example: A water meter counts thegallons of water flowing through it.

AMPERAGE UNITS Current flow is measured in unitscalled Amperes or AMPS.

Amperage measurements can use

different value prefixes, such asmicroamp, milliamp, and Amp.

AMPERAGE LESS THANBASE UNIT

LESS THANBASE UNIT

BASICUNIT

Symbol µA mA A

Pronounced

Microamp milliamp Amp

Multiplier 0.000001 0.001 1

AFFECTS OF CURRENT

Two common effects of current flow are

Heat Generation and Electromagnetism. HEAT: When current flows, heat will be

generated. The higher the current flow thegreater the heat generated. An example

would be a light bulb. If enough currentflows across the filament, it will glow whitehot and illuminate to produce light.

AFFECTS OF CURRENT

ELECTROMAGNETISM: When currentflows, a small magnetic field iscreated. The higher the currentflow, the stronger the magneticfield. An example:Electromagnetism principles areused in alternators, ignitionsystems, and other electronicdevices.

RESISTANCE Resistance is the force that reduces orstops the flow of electrons. It opposesvoltage.

Resistance is the force that reduces orstops the flow of electrons. It opposesvoltage.

MEASUREMENT Example: Water

flows through agarden hose, andsomeone steps onthe hose. Thegreater thepressure placed on

the hose, thegreater the hoserestriction and theless water flows.

RESISTANCE UNITS

Resistance is measured in unitscalled OHMS.

Resistance measurements can use

different value prefixes, such as Kiloohm and Megaohms.

AMPERAGE BASIC UNIT MORE THANBASE UNIT

MORE THANBASE UNIT

Symbol K M

Pronounced Ohm Kilo ohm Megaohm

Multiplier 1 1,000 1,000,000

RESISTANCEF

ACTORS Various factors can affect the

resistance. These include:

LENGTH of the conductor. The longerthe conductor, the higher theresistance.

LENGTH of the conductor. The longer

the conductor, the higher theresistance.

RESISTANCE FACTORS

TEMPERATURE of the material.Depending on the material, most willincrease resistance as temperatureincreases.

PHYSICAL CONDITION (DAMAGE) to thematerial. Any damage will increaseresistance.

TYPE of MATERIAL used. Variousmaterials have a wide range of resistances.

TYPES OF ELECTRICITYTwo basic types of Electricity classifications:

STATIC ELECTRICITY is electricity

that is standing still. Voltage potentialwith NO electron flow.

DYNAMIC ELECTRICITY is electricitythat is in motion. Voltage potential

WITH electron flow. Two types of Dynamic electricity exist:

TYPES OF ELECTRICITYTwo basic types of Electricity classifications:

Direct Current (DC) Electron Flow is

in only one direction.

Alternating Current (AC) Electronflow alternates and flows in bothdirections (back and forth).

STATIC ELECTRICITY

Voltage potential with NO electronflow.

STATIC ELECTRICITY

Example: By rubbing a silk cloth on aglass rod, you physically removeelectrons from the glass rod and place

them on the cloth. The cloth now has asurplus of electrons (negatively charged),and the rod now has a deficiency of electrons (positively charged).

STATIC ELECTRICITY

Another example: Rub your shoes on arug and then touch a metal table or

chair .... Zap!! The shock you felt wasthe static electricity dissipating throughyour body.

DYNAMIC ELECTRICITY

Is electricity in motion, meaning youhave electrons flowing, in other words

voltage potential WITH electron flow.

DYNAMIC ELECTRICITY

Two types of dynamic electricity

exists:± Direct Current (DC)

± Alternating Current (AC)

DIRECT CURRENT (DC)

Electricity with electrons flowing in onlyone direction is called Direct Current or

DC. DC electrical systems are used in cars.

ALTERNATING

CURRENT (AC) Electricity with electrons flowing back

and forth, negative - positive- negative,is called Alternating Current, or AC.

The electrical appliances in your homeuse AC power.

SOURCES OF

ELECTRICITY

Electricity can be created by several

means: Friction, Heat, Light, Pressure,Chemical Action, or Magnetic Action.

Only a few of these sources of energyare used in the automobile. The battery

produces electricity through chemicalaction, and the alternator produceselectricity through magnetic action.

SOURCES OF

ELECTRICITY Friction creates static electricity.

Heat can act upon a device called athermo couple to create DC.

Light applied to photoelectric materialswill produce DC electricity.

Pressure applied to a piezoelectricmaterial will produce DC electricity.

Chemical Action of certain chemicalswill create electricity.

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