A/C GENERATORSA/C GENERATORS

PRINCIPLESPRINCIPLES

OFOF

OPERATIONOPERATION

OPERATIONOPERATION

The generator converts mechanical The generator converts mechanical energy into electrical energy.energy into electrical energy.

Mechanical energy is given by means of a Mechanical energy is given by means of a drive belt, from the crankshaft.drive belt, from the crankshaft.

MAJOR COMPONENTSMAJOR COMPONENTS

Housing ( drive and rear)Housing ( drive and rear)

RotorRotor

StatorStator

RectifierRectifier

Brush AssemblyBrush Assembly

Voltage Regulator (Integral)Voltage Regulator (Integral)

Drive PulleyDrive Pulley

PrinciplesPrinciples

HOUSINGSHOUSINGS

Drive HousingDrive Housing: Supports the front of the : Supports the front of the rotor shaft, as a large bearing pressed or rotor shaft, as a large bearing pressed or flanged bolted. Has mounting holes for flanged bolted. Has mounting holes for installation on to engine via a bracket.installation on to engine via a bracket.

End Housing: Anchoring point for Brush End Housing: Anchoring point for Brush holder, Regulator, Rectifier and Stator holder, Regulator, Rectifier and Stator assembly. Also supports the rear of the assembly. Also supports the rear of the rotor shaft via small bearing. rotor shaft via small bearing.

HousingsHousings

ROTORROTOR

Purpose: The rotor is used to create a Purpose: The rotor is used to create a magnetic field, and rotate that magnetic magnetic field, and rotate that magnetic field inside the stator at varying speeds.field inside the stator at varying speeds.

PartsParts Projections (2) North and South Projections (2) North and South Rotor shaftRotor shaft Field WindingsField Windings Slip RingsSlip Rings

ROTOR CONSTRUCTIONROTOR CONSTRUCTION

BRUSHES AND SLIP RINGSBRUSHES AND SLIP RINGS

Purpose: To direct current to the rotating Purpose: To direct current to the rotating field windingsfield windings

ConnectionsConnections F (field terminal) ExternalF (field terminal) External Voltage regulator (insulated)Voltage regulator (insulated) Exciter DiodesExciter Diodes

Brushes and Slip RingsBrushes and Slip Rings

STATORSTATOR

Purpose: To collect Purpose: To collect the magnetic field the magnetic field created by the rotorcreated by the rotor

PartsParts 3 or 4 phase windings3 or 4 phase windings Laminated steel frameLaminated steel frame

Winding typesWinding types WyeWye DeltaDelta

Stator ConstructionStator Construction

STATOR STATOR

The Stator produces a Analog Signal, that The Stator produces a Analog Signal, that produces Alternating Currentproduces Alternating Current

Output is determined by Output is determined by Magnetic field strengthMagnetic field strength Rotor speedRotor speed Winding type (delta or wye)Winding type (delta or wye) Winding lengthWinding length Number of phases (windings)Number of phases (windings)

Stator OperationStator Operation

RectificationRectification

Purpose: Change the current from AC to Purpose: Change the current from AC to DCDC

PartsParts Diodes: Three positive and three negative.Diodes: Three positive and three negative. Exciter Diodes: Controls field current at Exciter Diodes: Controls field current at

Startup giving us full field current after start-Startup giving us full field current after start-up.up.

Heat Sink: Aluminum webbing linking diodes Heat Sink: Aluminum webbing linking diodes to end frame.to end frame.

Rectification PartsRectification Parts

Rectification OperationRectification Operation

Voltage RegulatorVoltage Regulator

Purpose: To control the current flow Purpose: To control the current flow through the field windings.through the field windings.

Process: Switches current flow on and off Process: Switches current flow on and off in the field windings, by watching line in the field windings, by watching line voltagevoltage

RegulationRegulation