DC GENERATOR

1. INTRODUCTION
It isbeneficial tounderstandthe topicasa whole.Whatispowerengineering?Itisa subfieldof
engineeringanddealswith:the generation,transmissionanddistributionof electricpoweraswell as
electrical devicesconnectedto systems.Some of these systemsincludegenerators,motors,and
transformers.Itconsistsof a networkthatconvertsdifferentformsof energyintoelectrical energy.
An electricgeneratorisadevice thatconvertsmechanical energytoelectrical energy. Thisisdone by
the flow inthe form of electriccharge that is forcedto flow bythe generator. Anelectricgenerator
consistsof a magnetand a coil where the magnetor the coil movesto produce a change influx over
time.Thisproducesa currentto flow;because change influx overtime isproportional tothe potential
of the sub-circuitanda flowof currentisrequiredtogenerate afield.
Permanentmagnetgenerators are superioralternativestotraditional inductionmotorsthatcanbe
coupledwithturbines, diesel generators andusedforhybridvehicles.One of the biggestbenefitsof
permanentmagnetgeneratorsisthatthese donotrequire definiteenvironmentalconditionstowork
properlywhichallowsthemtobe usedforwindenergyandwaterenergyprojects.Permanentmagnet
generatorsare relativelyeasytosetupand these are alsosmall insize which furtheraddsto the
mobilityandhelpsinsavingspace inaplace where these are installed.
At the core of the workingmechanismof PMgeneratorsare powerful magnets.Whenthe magnets
rotate around conductingwires,itcreateselectricitywhichissufficientforusage inanythingfroma
small home toa large powerplant.The powerful magnetsinthe standardPMgeneratorsare able torun
for more than 25 years.The magnetsusedinthese generatorsare speciallyconstructedandcertifiedfor
longtermusage and once installedcanworkfor yearswithoutneedingreplacement.
OBJECTIVES
The intentof thisstudyis to buildadc generator. The goal of the designisto lightup10 LEDs usingthe
dc generatorcreated.
MATERIALS AND METHODS
Thispart of the paperis the materialsandmethodsperformedforthe accomplishmentof the design.To
make ease forgatheringof data in designingaDC generator,the groupsearchedinYoutube forDC
Generatorvideos.The datagatheredbecame the basisof computationsforthe designof the project.
PermanentMagnet
A permanentmagnetisanobjectmade froma material thatismagnetizedandcreatesitsown
persistentmagneticfield. Asthe name suggests,apermanentmagnetis'permanent'.Thismeansthatit
alwayshasa magneticfieldandwilldisplayamagneticbehavioratall times. A neodymiummagnet is

2. the most widelyusedtype of rare-earthmagnet,isapermanentmagnetmade froman alloy of
neodymium,ironandboron toformthe Nd2Fe14Btetragonal crystalline structure.
MagneticWire
Magneticwire isgenerallymade of eithercopperoraluminum, althoughcopperproducesmuchbetter
resultswithlesswire.Before the copperoraluminumiswound,the wire iscoatedwithathinlayerof
insulationtoprotectusersandotherdevice componentsfromthe electricitythatpassesthroughit.
Magneticwire isthenwoundintoa coil in orderto produce electromagneticeffects,althoughthe wire
itself isnotmagnetic.
RESULTS AND DISCUSSION
Thispart of the studyshowsthe parameters consideredinordertocomplete the studythatwill serveas
the basiswhetherornot the designisonthe righttrack.
The overall efficiencyof small permanentmagnetdcgeneratorsisdeterminedbyseveral independent
factors.
1. Magnet type and strength
2. Magnetic gap - the smallerthe clearance betweenarmature polesandmagnets,the betterthe
magneticflux pathandthe higherthe efficiency.
3. Windingresistance
The lowerthe internal electrical resistance of the winding,the lessenergyisdissipatedasheatthat
resultsfromcurrentflowthroughthe windingresistance. The type of wire usedin thisstudy iscalled
magneticwire.Thistype of wire hasa varnishtype of isolation.
The lengthandgage of the wire usedin the coilswill greatlyaffectthe output.The greaterthe number
of turnsinthe coil will increase the amountof magneticfluxcutbythe coil whichwill increase the
electrical output.Alsothe thickerthe wire the more ampsthe wire will produce. There are 1500 turns
made to act as a coil usinga 34 magneticwire.
4. Heat - bothambientheatandheat generatedbycurrentflow throughthe windings - the higherthe
temperature,the higherthe resistance andthe lowerthe efficiency.Aircoolingof windings,both
convective and forcedair,improvesthe generatorefficiency.
5. Windage - the resistance torotationcausedbyair frictionaroundthe rotatingarmature - is higherfor
verynarrow magneticgaps,andis alsohigherathighershaftrpms as well aslargerarmature diameters.
6. Load characteristics - the nature of the generatorload,acompletelyexternalfactor,influencesthe
overall efficiency.Generally,the maximumefficiencyoccurswhenthe source (generator) impedance is
matchedto the external loadimpedance.In dcgenerators,impedance effectsoccurwhenthe
inductance of the generatorwindingsinteractsinanywaywiththe load.A non-inductiveloadsuchasa

3. batteryor a resistance heatercanbe consideredpurelyresistive,while the generatorimpedance isthen
simplyitsinternal dcresistance.