1001ENG1001ENGEngineering Engineering Practice and Practice and

SustainabilitySustainabilityIntroduction to ElectronicsIntroduction to Electronics

ECE StructureECE Structure Lectures:Lectures:

Introduction to ElectronicsIntroduction to Electronics Component IdentificationComponent Identification Mechanical WorkshopMechanical Workshop Electrical SafetyElectrical Safety Electrical Specification and DatasheetsElectrical Specification and Datasheets

Labs:Labs: GRUB (weeks 1-3)GRUB (weeks 1-3) Soldering and fault-finding (weeks 4-5)Soldering and fault-finding (weeks 4-5) Power Supply (weeks 7-12)Power Supply (weeks 7-12)

ResourcesResources Maxwell website:Maxwell website:

maxwell.me.gu.edu.aumaxwell.me.gu.edu.au go to course information – 1001ENGgo to course information – 1001ENG

Required equipment:Required equipment: Power supply – mechanical:Power supply – mechanical: $37.65$37.65 Power supply – electrical:Power supply – electrical: $13.70$13.70 Bikelight kit:Bikelight kit: $4.30$4.30 Toolkit:Toolkit: $40.75$40.75

All items are kept by you at end of labsAll items are kept by you at end of labs If you have all toolkit items already, you need not If you have all toolkit items already, you need not

purchase itpurchase it All items can be purchased from the Science Store All items can be purchased from the Science Store

in N34in N34

Laboratory InformationLaboratory Information

Bikelight:Bikelight: simple soldering exercise to build a set of flashing simple soldering exercise to build a set of flashing

lightslights undertaken in the week 4 lab session, takes undertaken in the week 4 lab session, takes

approximately 2 hours to completeapproximately 2 hours to complete all instructions are on the maxwell websiteall instructions are on the maxwell website graded by attendance and final result (5%)graded by attendance and final result (5%)

Fault-finding:Fault-finding: groups are supplied with non-working bikelights, groups are supplied with non-working bikelights,

and must find the faultsand must find the faults an assessed exercise contributing to 5% of the an assessed exercise contributing to 5% of the

course gradecourse grade

Power Supply ProjectPower Supply Project The major project undertaken during this The major project undertaken during this

coursecourse A group project, however each student builds A group project, however each student builds

their own PSUtheir own PSU 5 person groups5 person groups each member has a specific roleeach member has a specific role

Assessment:Assessment: worth 25% of the total marks for the courseworth 25% of the total marks for the course mark is based on attendance, quality of work and mark is based on attendance, quality of work and

final reportfinal report All PSUs are thoroughly tested for electrical All PSUs are thoroughly tested for electrical

safetysafety The final working (??) power supply is yours to The final working (??) power supply is yours to

keep and usekeep and use

Roles within GroupsRoles within Groups

General Manager:General Manager: oversees all aspects of developmentoversees all aspects of development responsible for all bookings and responsible for all bookings and

communicationcommunication must be able to step in to any other role if must be able to step in to any other role if

requiredrequired Assembly Manager:Assembly Manager:

responsible for guiding group through the responsible for guiding group through the PCB population stage of the projectPCB population stage of the project

must attend the assembly managers’ must attend the assembly managers’ workshop in week 5 (PM)workshop in week 5 (PM)

Roles within GroupsRoles within Groups Workshop Manager:Workshop Manager:

must attend layout and metalwork course in week must attend layout and metalwork course in week 7 (PM), and instruct remainder of group7 (PM), and instruct remainder of group

responsible for booking metalwork workshop for responsible for booking metalwork workshop for group and ensuring all members complete on timegroup and ensuring all members complete on time

Construction Manager:Construction Manager: responsible for the construction phase of the responsible for the construction phase of the

project – assembling the case, transformer and project – assembling the case, transformer and PCBPCB

ensures all safety precautions are taken during ensures all safety precautions are taken during construction, and checks all PSUs in the groupconstruction, and checks all PSUs in the group

must attend the construction workshop in week 8 must attend the construction workshop in week 8 (PM) and instruct remainder of group during next (PM) and instruct remainder of group during next lablab

Roles within GroupsRoles within Groups Quality Assurance Manager:Quality Assurance Manager:

responsible for the testing and specification phase responsible for the testing and specification phase of the projectof the project

must organise group during fault correction and must organise group during fault correction and specification labsspecification labs

must attend the QA managers workshop in week 8 must attend the QA managers workshop in week 8 (PM)(PM)

All group members:All group members: must participate during each normal lab sessionmust participate during each normal lab session are responsible for the safety and cleanliness of are responsible for the safety and cleanliness of

the laboratorythe laboratory should act in a responsible manner at all timesshould act in a responsible manner at all times must inform the demonstrator of any inappropriate must inform the demonstrator of any inappropriate

and/or dangerous activities in the laband/or dangerous activities in the lab

Basics of ElectronicsBasics of Electronics There are two types of skills an electronics There are two types of skills an electronics

engineer requires:engineer requires: Theoretical:Theoretical:

maths and electronics theory necessary to maths and electronics theory necessary to design circuits and systemsdesign circuits and systems

can be taught by lectures, textbooks, etc..can be taught by lectures, textbooks, etc.. Practical:Practical:

physical skills required to implement designsphysical skills required to implement designs includes such things as soldering, mechanical includes such things as soldering, mechanical

skills, assembly, fault-finding, etc..skills, assembly, fault-finding, etc.. must be must be practicedpracticed regularly to maintain regularly to maintain

proficiencyproficiency

SolderingSoldering Soldering is the process of joining two Soldering is the process of joining two

electronic components by applying a molten electronic components by applying a molten conducting metal alloyconducting metal alloy typically soldering is used to attach components to typically soldering is used to attach components to

a printed circuit board (PCB) or similara printed circuit board (PCB) or similar Soldering serves two purposes:Soldering serves two purposes:

establishes a establishes a mechanicalmechanical connection between the connection between the PCB and the component so it doesn’t fall offPCB and the component so it doesn’t fall off

establishes an establishes an electricalelectrical connection between the connection between the PCB and the component to transmit and electrical PCB and the component to transmit and electrical signalsignal

Being able to solder correctly and efficiently Being able to solder correctly and efficiently will save you a lot of time and headaches in will save you a lot of time and headaches in future yearsfuture years

What is Solder?What is Solder? Solder is a metal alloy with a low melting point used Solder is a metal alloy with a low melting point used

to metallurgically join electronic components togetherto metallurgically join electronic components together typical solder is a tin/lead alloytypical solder is a tin/lead alloy certain percentage alloys actually have a lower melting point certain percentage alloys actually have a lower melting point

than than eithereither tin or lead! tin or lead! 63/37 tin:lead is the ‘best’ ratio (Eutectic point), however 63/37 tin:lead is the ‘best’ ratio (Eutectic point), however

60/40 is also very common60/40 is also very common Solder also typically contains ‘flux’, which is used to Solder also typically contains ‘flux’, which is used to

clean oxidisaion from the surfaces to be joinedclean oxidisaion from the surfaces to be joined also keeps air from the joint while soldering and assists in also keeps air from the joint while soldering and assists in

wettingwetting note that this does note that this does notnot clean dirt, oil, rust, etc from the clean dirt, oil, rust, etc from the

surfacesurface most commonly used solders have a flux coremost commonly used solders have a flux core

Solder for traditional PCB use comes in wire form, of Solder for traditional PCB use comes in wire form, of various diametersvarious diameters

Solder Melting PointsSolder Melting Points

Tin/Lead RatioTin/Lead Ratio Melting Point (C)Melting Point (C)

0/1000/100 327327

40/6040/60 230230

50/5050/50 214214

60/4060/40 190190

63/3763/37 183183

95/595/5 224224

100/0100/0 232232

The Soldering IronThe Soldering Iron A soldering iron is a device used to apply heat to A soldering iron is a device used to apply heat to

solder, allowing it to melt in the desired locationsolder, allowing it to melt in the desired location The temperature of the iron can be controlled The temperature of the iron can be controlled

using the “Curie effect”using the “Curie effect” The tip of a soldering iron is specially designed The tip of a soldering iron is specially designed

and must be treated with careand must be treated with care this is the ‘wettable’ part of the iron, the part to which this is the ‘wettable’ part of the iron, the part to which

solder will ‘stick’solder will ‘stick’

The Soldering IronThe Soldering Iron You should always ensure that:You should always ensure that:

you are soldering on a heat-resistant surfaceyou are soldering on a heat-resistant surface the tip is kept ‘wet’ when in use, that is it has the tip is kept ‘wet’ when in use, that is it has

a thin coating of solder on it at all timesa thin coating of solder on it at all times you do not abrade the tip of the ironyou do not abrade the tip of the iron the iron is not left turned on when not in usethe iron is not left turned on when not in use the temperature is not set too highthe temperature is not set too high

After use, you should:After use, you should: clean the tip with a damp spongeclean the tip with a damp sponge apply a coating of solder to the tipapply a coating of solder to the tip allow to cool before storingallow to cool before storing

Correct Soldering Correct Soldering TechniqueTechnique

Place the components to be soldered into the correct holes in Place the components to be soldered into the correct holes in the PCBthe PCB the legs should protrude onto the side the legs should protrude onto the side withwith the copper tracks the copper tracks the component should be pushed fully onto the surface of the the component should be pushed fully onto the surface of the

PCB where possiblePCB where possible wires should be ‘tinned’ or coated with solder before being wires should be ‘tinned’ or coated with solder before being

placed onto the boardplaced onto the board Turn the PCB over and secure firmlyTurn the PCB over and secure firmly Heat the joint with the soldering ironHeat the joint with the soldering iron

touch both the component leg and the copper track touch both the component leg and the copper track simultaneouslysimultaneously

allow to heat for 2-3 secondsallow to heat for 2-3 seconds Apply the solder to the jointApply the solder to the joint

hold against the iron, component leg and PCBhold against the iron, component leg and PCB you should see smoke as the flux in the solder burns offyou should see smoke as the flux in the solder burns off remove solder after the smoke disappears (about 2 seconds remove solder after the smoke disappears (about 2 seconds

later)later) finally, remove the soldering iron from the jointfinally, remove the soldering iron from the joint

Correct Soldering Correct Soldering TechniqueTechnique

Good and Bad JointsGood and Bad Joints

Things to ConsiderThings to Consider

The copper on PCBs is held onto the The copper on PCBs is held onto the fiberglass with gluefiberglass with glue this glue melts at 150C while solder melts at this glue melts at 150C while solder melts at

180C!180C! this is a this is a design featuredesign feature which allows the copper which allows the copper

to move slightly as it expands with heatto move slightly as it expands with heat To prevent damage to the PCB, don’t:To prevent damage to the PCB, don’t:

apply too much pressure with the ironapply too much pressure with the iron move the PCB or iron excessively while heatingmove the PCB or iron excessively while heating design PCBs with very small unconnected copper design PCBs with very small unconnected copper

regionsregions

Surface Mount SolderingSurface Mount Soldering A newer soldering technique where components are A newer soldering technique where components are

soldered onto the soldered onto the toptop of the PCB of the PCB much smaller PCB area requiredmuch smaller PCB area required considerably more preciseconsiderably more precise more efficient use of PCB spacemore efficient use of PCB space

Requires a more complicated approachRequires a more complicated approach good eyesight and/or a magnifier and a steady hand are good eyesight and/or a magnifier and a steady hand are

requiredrequired apply a bead of solder to one pad, then apply flux to all apply a bead of solder to one pad, then apply flux to all

padspads move the component into position and apply heat to the move the component into position and apply heat to the

bead of solder, ensuring a correct positionbead of solder, ensuring a correct position apply solder to each other connection ensuring good apply solder to each other connection ensuring good

wettingwetting reheat first connection again to ensure good connectionreheat first connection again to ensure good connection

Surface Mount SolderingSurface Mount Soldering