Bosch Alternators

Fig. 1 Bosch alternator w/integral regulator:

Fig. 2 Rear view of Bosch alternator w/external regulator:

Fig. 3 Rear view of Bosch alternator w/regulator in-engine electronics:

The main components of the Bosch alternator are the front and rear housings, stator windings, rotor and rectifying diodes. Current is supplied to the rotor through slip rings and two brushes which, on integral regulator units, are built into the voltage regulator positioned on the rear housing. The rotor is supported in the front and rear housings by ball bearings. The stator windings are assembled inside a laminated core which forms part of the alternator frame. A diode plate containing positive and negative diodes is soldered to the stator winding leads.
Alternator field current is supplied through a diode trio which is also connected to the stator windings. A capacitor which is mounted to the rear housing, protects the diode plate assembly from high voltages and suppresses radio noises. On all units, the voltage regulator is solid state, which is not serviceable or adjustable. On integral regulator units, the voltage regulator can be replaced without disassembling the alternator. On units with voltage regulator in-engine electronics, the electronic voltage regulator is contained within engine electronics Power Module and Logic Module.