ATM 202 Automotive ATM 202 Automotive Electricity Electricity

Instructor : Matthew PenceEmail: pensky@mediaone.netBook:Automotive Electricity & Electronics 2nd Ed. Barry HollembeakHours: Monday 6:00pm – 9:30pm

Wednsday 6:00pm – 10:00pm

• The Atomic StructureThe Atomic Structure

•What is an Atom?What is an Atom?

• An atom is the smallest particle on An atom is the smallest particle on any element.any element.

• Element – oxygen (O) or hydrogen Element – oxygen (O) or hydrogen (H)(H)

• Compound – two or more elements Compound – two or more elements combined together – water (H2O)combined together – water (H2O)

• Molecule – Smallest particle of a Molecule – Smallest particle of a compoundcompound

• Atom BasicsAtom Basics

• Valence RingValence Ring

• Free Electrons Free Electrons

ConductorConductor

• Supports the flow of electrons Supports the flow of electrons

• Popular Conductors:Popular Conductors:– Copper, Silver, gold, iron, aluminumCopper, Silver, gold, iron, aluminum– Each have three or less free electrons Each have three or less free electrons

in it’s valence ring.in it’s valence ring.

InsulatorsInsulators

• Cannot support the flow of Cannot support the flow of electronselectrons

• Five of more free electrons in it’s Five of more free electrons in it’s valence ringvalence ring

• Popular insulators:Popular insulators:– Glass, plastic, rubber, paper, woodGlass, plastic, rubber, paper, wood

SemiconductorsSemiconductors

• Not good conductors or insulatorsNot good conductors or insulators• Four free electrons in valence ring.Four free electrons in valence ring.• Silicon most popular, made from Silicon most popular, made from

sandsand

ElectricityElectricity

• Electricity is the flow of electrons Electricity is the flow of electrons through a conductor.through a conductor.

• The human body runs on electrical The human body runs on electrical impulsesimpulses

• The human body conducts The human body conducts electricity!!!electricity!!!

Electrical TheoriesElectrical Theories

• Electron theory – electrons moving Electron theory – electrons moving from negative to positivefrom negative to positive

• Conventional theory – electrons Conventional theory – electrons flow from positive to negativeflow from positive to negative

• Does it make a difference?Does it make a difference?

Electromotive Force -Electromotive Force -VoltageVoltage

Electrical Flow – CurrentElectrical Flow – Current

AC/DC – Highway to HellAC/DC – Highway to Hell

• Alternating current – Voltage that Alternating current – Voltage that moves from positive to negative at moves from positive to negative at a frequency that can varya frequency that can vary

• Direct Current – Voltage stays the Direct Current – Voltage stays the same in moves in one directionsame in moves in one direction

Electrical Restriction – Electrical Restriction – ResistanceResistance

ReviewReview

• Voltage – Electrical pressure, potential, Voltage – Electrical pressure, potential, measured in Voltsmeasured in Volts

• Current – Flow of electrons past a certain Current – Flow of electrons past a certain point in a given time, measured in Amps: point in a given time, measured in Amps: 6.25 Billion Billion electrons per second = 6.25 Billion Billion electrons per second = 1 amp1 amp

• Resistance – Opposition to current flow, Resistance – Opposition to current flow, load or work, consumes voltage, load or work, consumes voltage, measured in measured in ohmsohms