2 Alternator Functional Diagram DC Current Applied to the Rotor
3 Alternator Functional Diagram 3-Φ AC Output from the StatorDC Current Applied to the Rotor
4 Alternator Functional Diagram 3-Φ AC Output from the StatorDC Current Applied to the RotorSix Output Diodes Two per Phase Full-Wave Rectifier
5 Alternator Functional Diagram 3-Φ AC Output from the StatorDC Current Applied to the RotorSix Output Diodes Two per Phase Full-Wave RectifierThree Diodes One per Phase Sample Battery Voltage
6 Alternator Functional Diagram 2 InputsRegulator Controls the Amount of Field Current applied to the Rotor
7 Regulator Inputs Control Voltage Input Field Current Supply Controls current through the RotorField Current SupplyOne input from the alternator via the Diode TrioSecond input from the battery via the warning lamp
8 Regulator ActionIf the battery voltage drops, more current applied to the rotor, increasing the magnetic field strength, increasing the alternator voltage output.If the battery voltage increases, less field current applied to the rotor, reducing the alternator voltage output.
9 Field Current Supply Two Sources Turn ignition ON, Alternator via the diode trioBattery via the warning lampTurn ignition ON,Source of field current is the battery via the ignition switch and the warning lamp
10 Field Current Supply (continued) After engine starts,Alternator is up to speed, output of diode trio is fed back to the regulator and serves as the source of the field current.Alternator is now self-sustaining
12 Warning Lamp Turn ignition ON, Alternator at full output, Current flows through warning lamp, transistors, and field coil to ground, causing the lamp to illuminate.Alternator at full output,Voltage from diode trio equals the battery voltageequal voltage on both sides of lamplamp goes out.
13 Warning Lamp (continued) If the alternator fails,Voltage out of diode trio dropsLamp illuminates from the battery voltageIf the battery fails,Battery voltage dropsLamp illuminates from the alternator voltage
14 Sample Battery Voltage Inside the RegulatorIC1+Ic2Ic2Field CurrentIc1Sample Battery Voltage
15 Regulator Circuit When battery voltage is OK, D1 conducts T2 conducts Less current through T1 collectorT3 turns OffField current now reduced
16 Regulator Circuit (continued) When battery voltage is low,D1 is OffT2 is OffMore current flows through T1collectorTransistor T3 turns OnField current increases