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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