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Understanding The Alternator

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By Anvil09


How The Alternator Works

The Alternator Or AC-Motor As Nicola Tesla, The Inventor Of The Device Called It. Is One Of The Most Amazing Devices We Have Available To Create Electrical Energy. And Can Be Found In Almost Every Automobile That Has Been Produced, Sense The 1960s.

This Article Is Going To Attempt To Enlighten The Reader, As To How It Works, And How They Can Make It Work For Them, To Produce There Own Electrical Energy As Well As To Remove Some Of The Missinformation, Lack Of Understanding, And The Preputal Dogma That Has Been Created By Industry That Says It Cant Be Done.

This Article Is Also Designed For Individuals That Have A Firm Understanding In Basics Electronics, And Should Not Be Attempted By Any one That Dose Not Or Has Not Worked With Electronics.

Those That Wish To Do So Are Risking There Own Life And Should Seek Profesional Assistance .

Let Us First Look At The 3 Diferant Alternators Or AC-Generators That Are Curently In Use.


3-Key Types

 These Are The Three Key Type's Of Stators Used In Industry, And The Standard Voltages That Are Obtained From There Out Puts

Keep In Mind That They Are All Large Transformers And Are Wire Coils And Just Like Any Coil They React As A Resistance

Basic Electronics Shows Us That;

Resistance In Parallel Will Act As The Lowest Resistance In The Circuit. And In Series Will Act As The Total Of All Of The Resistance Combined 

When In Parallel The Same Voltage At The Out Put And The Amperage Drops Across Each Resistor

When In Series The Voltage Drops Across Each Resistor And The Amperage Remains The Same 

The Delta Will Produce Higher AmperageBecause The Windings Are In Parallel With Each Other. Just Like Tying 3 Transformer Out Puts Togather In Parallel The Amperage Increases And The Voltage Stays The Same

The Star Will Produce Higher Voltages At The Same Amperage And Is The Same As Tying A Single Transformer To A  Large Center Taped Transformer And Obtaining The Voltage Out Puts From Each Transformer As Well As At The Center Tap

The Wye Will Produce Higher Voltages At The Same Amperage And Id The Same As Tying A Single Transformer To A Large Center Taped Transformer And Obtaining The Voltage Out Puts From Each Transformer Out Put But Dose Not Utilize The Center Tap As An Out Put    

 

The Rotor And How It Works

Understanding The Field Coil

The Field Coil Is A Copper Wire That Is Wrapped Around A Spool, The Shaft And Pole Plates Wrap Around The Coil And Are Made Of Iron. And When DC Voltage Is Applied The Pole Plates Become Magnetized.

The Way In Which They Are Place Together Gives Us Multiple Magnets With North And South Poles The Amount Of Fingers On Each Pole Matches The Amount Of Fingers On The Opposite Pole For Each Finger = 1 Magnet

The Rotor Is Then Placed Inside Of The Stator Core And Is Spun Around. "Notice" That The Pole Plates Are North And South.This Causes The Magnetic Lines Of Force To Cut Through The Copper Wire In The Stator. And Induces Voltage To Travel To The Out Puts Of The Stator Wires.

Remember That The Stator Is A Big Transformer The Only Difference Hear Is That We Do Not Have A Primary Coil Plugged Into The Wall Outlet Providing Alternating Current To Be Induced In The Secondary Which In This Case Is The Stator.

The Primary Is A DC Voltage And The Out Put Is AC And Is Obtained Mechanically By Spinning The Rotor.

And Because The Pole Plates Have Fingers That Lay Inbetween One Another The Magnetic Lines Of Force Change As The Rotor Spins Inside The Stator, The Voltage Alternates At The Out Puts Of The Stator Providing Alternating Current.

It Should Be Noted That The Faster The Rotor Spins The Higher The Voltage At The Out Puts Of The Stator "Caution" Should Be Used Voltages Can Exceed Acceptable Limits And Go As High A 600v AC And The Frequency Used In Household Current Is Most Often 50 To 60 Hz "Spin The Rotor To Fast And The Frequency Increases Well Above Acceptable Limits"

So Hears How To Calculate The Proper Speed To Obtain 60Hz With A Alternator If You Have A Single Magnet Spinning Inside The Stator That Is To Say One North And One South You Need 60 Cycles Per Second X 60 Seconds = 3600 Rpm

To Determine How Many Lines Of Magnetic Force Are Being Cut By The Alternator It Is Necessary To Count The Finger On The Pole Plates

Then Divide The Number Into 3600 Example Most Automotive Alternators Have 6 Fingers North And 6 Finger South So We Have 6 Magnets So We Divide 3600 By 6 That = 600 Rpm Providing 60Hz

Keep In Mind Not All Alternators Have The Same Amount Of Fingers And They Range From 3 To 8 Fingers Dependent On The Manufacturer

Keep In Mind That Most Electrical Equipment That We Use Runs Or Operates At 50 To 60 Hz Any Faster And The Wires And Components Get hot And Burn Up

It Should Also Be Noted That The Amount Of Current-Amperage At The Out Put Will Not Change Just The Voltage The Reason For This Is That The Magnetic Lines Of Force Are The Same Regardless Of How Fast The Rotor Spins

The Magnetic Force Created Determines The Amperage The Stronger The Magnetic Force The Higher The Amperage

The Amperage Is Also Dependent On The Gauge Of Wire That Is Used The Heaver The Wire The More Amperage That They Can Handle

The Field Coil It Self Is Usually Finer Wire Than The Stator Coils And Dose Not Need To Be Of a Heavy Guage The More Wraps Of Wire The Stronger The Magnet The Stator On The other Hand Needs To Be Of Substantial Gauge Usually 18 Or 16 Gauge Is Used

Standard Set Up

Standard Automotive Set Up

These Are Typical Automotive Set Ups 

Notice That There Is A Capacitor And A Set Of Diodes

The Capacitor  Acts As A Condenser And Absorbs The Excess Voltage From The Coil When It Stops Producing

Coils Spike In Voltage When They Suddenly No Longer Have Power Out And Build Up A Massive Charge The Capacitor Absorbs This Spike And Allows It To Drain Slowly

The Diodes Act As A Bridge Rectifier Unit And Convert The AC Voltage Out To Be Converted Into DC Around 15 volts The Diodes Are Rated By The Amperage That They Can Handle And Can Be Purchased An Most Automotive Supply Houses 

They Are All Part Of The Same Alternator Unit In  The Regulator And Battery Are Most Often Separate Units But Some Alternators Have The Regulator Unit Built Into The Case

There Is Alot Of Information That Can Be Found About General Automotive Charging Systems On The Web Therefore I Will Not Go Into The CompleteDetails In This Article

For Now We Need To Cover The AC Side And Explain How To Obtain The Out Puts Desired
  

The AC Side

How To Get What We Want

To Summarize The Automotive Alternator Is 3 Phase And Its A Big Transformer Most Often Center Taped

Each Coil Will Be 120 Degrees Apart,

The Stator Iron Core Used In The Automotive Industry Usually Has 36 Slots To Hold The Wire Each Coil Will Most Often Wrap Around The Iron Core Of The Stator 3 Times

Meaning 3 Wires Of Each Coil Will Be Inserted Into Every Third Slot Giving You

12 Cuts Each Is Cut X 3 Wires Producing 1 Volt Per Cut X 12 = 36 Volts

Because 3 Wires Are Combined  And 120 Degrees Apart You Only Get 1 Volt At Higher Amperage

3 Wires Cut 12 Times For The First Phase = 36 Volts 

3 Wires Cut 12 Times For The Second Phase = 36 Volts

3 Wires Cut 12 Times For The Third Phase 36 Volts

If Rotor Is Turned 10 Full Revolution Per Second Or 600 Rpm And If It Has 6 Fingers = 60 Hz Using 2 Of The Coils To Obtain The AC Out Put

72 Volts At 60 Hz If The Coils Are In Parallel At The Available Amperage Of One Coil

Or 10 revolutions X 12 Volts = 72 volts

108 Volts At 60 Hz If They Were In Series At The Available Amperage Of All Three Coils 

Or 10 revolutions X 36 Volts = 108 Volts

There Are A Number Of Ways To Obtain The Voltage And Frequency Needed

1= A DC Motor Attached To The Battery On The Voltage Regulation Side Inverter Technology Tied In To The Charging System

2= Re-wire Dule Alternators To Run In Series And Attach A DC Motor To Drive The Alternators Run The DC Motor Off Of The Battery Allowing The Charging System To Keep The Battery Charged 

3=Re-Wire Single Or Duel Alternators And Run With AC Motor Tie In To A Relay So That The Motor Starts On The DC Side Until The System Is Energized And The AC Side Takes Over Allowing The Charging System To Re-Charge The Battery Until Needed Again

Just Remember All AC Outputs Need To Be Run Through A Circuit Breaker Box And Or Fused

Use Commen Sense Don't Try This Unless You Have A Good Working Knowledge Of Electronics And For God Sake Be Careful

Good Luck In Your Experamentation's  

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