GUIDE 1252933 - Caterpillar

Prestolite Alternator 1. Brush assembly. 2. Stator. 3. Rotor. 4. Roller bearing. 5. Slip rings. 6. Ball bearing.Alternator Regulator (Prestolite)
The voltage regulator is a solid state (transistor, no moving parts) electronic switch. It feels the voltage in the system and gives the necessary field current (current to the field windings of the alternator) for the alternator to make the needed voltage. The voltage regulator controls the field current to the alternator by switching on and off many times a second. There is a voltage adjustment screw on the back of the regulator. This voltage adjustment screw is used to meet different operating needs at different times of the year. An increase or decrease by 0.5 volts from the normal (N) setting is made by removing the regulator and changing the position of the adjustment screw. An increase to the voltage will be made by moving the screw to the "H" position.Alternator (Robert Bosch)
The alternator is driven by two V-type belts. It has a three phase full wave rectified output. The alternator is brushless.The rotor (4) and the bearings are the only moving parts. The alternator output is 35 amp.The main parts of the alternator are the stator (2) which has three phase windings, the rectifier (3) which changes the three phase AC to DC and provides excitation current.The field winding (1) is a stationary coil assembly that provides the magnetic field.The rotor provides the north and south poles which cut the magnetic field between the stationary field winding and the stator (2). North and south poles are separated magnetically by a non-magnetic ring (5).
6N9294 Alternator 1. Winding. 2. Stator. 3. Rectifier. 4. Rotor. 5. Non-magnetic ring.Generator
The generator is belt driven by the diesel engine. The generator keeps the battery charged and supplies current to operate the electrical components.
Cutaway View Of A Generator 1. Brush assembly. 2. Field. 3. Commutator. 4. Armature.Generator Regulator
The generator regulator controls the output of the generator. The regulator incorporates three controls: the cutout relay, the voltage regulator and the current regulator. Each control has contact points which are operated by electromagnets.Springs hold the cutout relay points open and the voltage regultor and current regulator contact points closed. The spring tension for each unit is a force opposing the force of the electromagnets.The cutout relay prevents the battery from motorizing a generator that is not producing enough voltage. Generator voltage approximately equal to battery voltage will close the cutout relay points. This closes the circuit between the generator and the battery. The generator can now supply the battery and the components of the electrical system with power.The voltage regulator prevents the generator from producing damaging high voltage. Generator voltage slightly higher than battery voltage opens the regulator points causing the generator output voltage to lower. Low generator voltage allows the spring to close the regulator points and generator voltage is again high. The action of the voltage regulator points, opening and closing, controls the output voltage of the generator. The points can open and close