1. FIGURE 20-1 A typical generator (alternator) on a Chevrolet V8 engine.

2. FIGURE 20-2 The end frame toward the drive belt is called the drive-end housing and the rear section is called the slip-ring-end housing.

3. FIGURE 20-3 An OAP on a Jeep generator with a diesel engine.

4. FIGURE 20-4A An OAD on a Chrysler vehicle generator.

5. FIGURE 20-4B An overrunning alternator dampener (OAD) disassembled, showing all of its internal parts.

6. FIGURE 20-5 A cutaway of a General Motors CS-130D generator showing the rotor and cooling fans that are used to force air through the unit to remove the heat created when it is charging the battery and supplying electrical power for the vehicle.

7. FIGURE 20-6 Rotor assembly of a typical alternator (AC generator)
FIGURE 20-6 Rotor assembly of a typical alternator (AC generator). Current through the slip rings causes the “fingers” of the rotor to become alternating north and south magnetic poles. As the rotor revolves, these magnetic lines of force induce a current in the stator windings.

8. FIGURE 20-7 A cutaway view of a typical AC generator (alternator).

9. FIGURE 20-8 An exploded view of a typical generator (alternator) showing all of its internal parts.

10. FIGURE 20-9 A diode symbol.

11. FIGURE Magnetic lines of force cutting across a conductor induce a voltage and current in the conductor.

12. FIGURE Sine wave voltage curve created by one revolution of a winding rotating in a magnetic field.

13. FIGURE When three windings (A, B, and C) are present in a stator, the resulting current generation is represented by the three sine waves. The voltages are 120° out of phase. The connection of the individual phases produces a three-phase alternating voltage.

14. FIGURE 20-13 Wye-connected stator winding.

15. FIGURE As the magnetic field, created in the rotor, cuts across the windings of the stator, a current is induced. Notice that the current path includes passing through one positive (+) diode on the way to the battery and one negative (-) diode as a complete circuit is completed through the rectifier and stator.

16. FIGURE 20-15 Delta-connected stator winding.

17. FIGURE 20-16 A stator assembly with six, rather than the normal three, windings.

18. FIGURE 20-17 Typical voltage regulator voltage range.

19. FIGURE A typical electronic voltage regulator showing the connections and the circuits involved.

20. FIGURE 20-19 Diagram of an A-type field circuit.

21. FIGURE 20-20 Diagram of an B-type field circuit.

22. FIGURE Typical General Motors SI-style AC generator with an integral voltage regulator. Voltage present at terminal 2 is used to reverse bias the zener diode (D2) that controls TR2.The hot brush is fed by the ignition current (terminal 1) plus current from the diode trio.

23. FIGURE A Hall-effect current sensor attached to the negative battery cable is used as part of the EPM system.

24. FIGURE 20-23 General Motors CS generator
FIGURE General Motors CS generator. Notice the use of zener diodes in the rectifier to help control any high-voltage surges that could affect delicate computer circuits. If a high-voltage surge does occur, the zener diode(s) will be reverse biased and the potentially harmful voltage will be safely conducted to ground. Voltage must be preset at the L terminal to allow the generator to start producing current.

25. FIGURE 20-24 The components inside a GM CS generator.

26. FIGURE The alternator field (rotor) current is controlled by the computer. SMEC stands for single module engine controller.