PRINCIPLES OF OPERATION A/C GENERATORS PRINCIPLES OF OPERATION

OPERATION The generator converts mechanical energy into electrical energy. Mechanical energy is given by means of a drive belt, from the crankshaft.

MAJOR COMPONENTS Housing ( drive and rear) Rotor Stator Rectifier Brush Assembly Voltage Regulator (Integral) Drive Pulley

Principles

HOUSINGS Drive Housing: Supports the front of the rotor shaft, as a large bearing pressed or flanged bolted. Has mounting holes for installation on to engine via a bracket. End Housing: Anchoring point for Brush holder, Regulator, Rectifier and Stator assembly. Also supports the rear of the rotor shaft via small bearing.

Housings

ROTOR Purpose: The rotor is used to create a magnetic field, and rotate that magnetic field inside the stator at varying speeds. Parts Projections (2) North and South Rotor shaft Field Windings Slip Rings

ROTOR CONSTRUCTION

BRUSHES AND SLIP RINGS Purpose: To direct current to the rotating field windings Connections F (field terminal) External Voltage regulator (insulated) Exciter Diodes

Brushes and Slip Rings

STATOR Purpose: To collect the magnetic field created by the rotor Parts 3 or 4 phase windings Laminated steel frame Winding types Wye Delta

Stator Construction

STATOR The Stator produces a Analog Signal, that produces Alternating Current Output is determined by Magnetic field strength Rotor speed Winding type (delta or wye) Winding length Number of phases (windings)

Stator Operation

Rectification Purpose: Change the current from AC to DC Parts Diodes: Three positive and three negative. Exciter Diodes: Controls field current at Startup giving us full field current after start-up. Heat Sink: Aluminum webbing linking diodes to end frame.

Rectification Parts

Rectification Operation

Voltage Regulator Purpose: To control the current flow through the field windings. Process: Switches current flow on and off in the field windings, by watching line voltage

Regulation