Transcript Alternator
Alternator Functional Diagram Alternator Functional Diagram DC Current Applied to the Rotor Alternator Functional Diagram 3-Φ AC Output from the Stator DC Current Applied to the Rotor Alternator Functional Diagram 3-Φ AC Output from the Stator DC Current Applied to the Rotor Six Output Diodes Two per Phase Full-Wave Rectifier Alternator Functional Diagram 3-Φ AC Output from the Stator DC Current Applied to the Rotor Three Diodes One per Phase Sample Battery Voltage Six Output Diodes Two per Phase Full-Wave Rectifier Alternator Functional Diagram 2 Inputs Regulator Controls the Amount of Field Current applied to the Rotor Regulator Inputs • Control Voltage Input – Controls current through the Rotor • Field Current Supply – One input from the alternator via the Diode Trio – Second input from the battery via the warning lamp Regulator Action • If 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. Field Current Supply • Two Sources – Alternator via the diode trio – Battery via the warning lamp • Turn ignition ON, – Source of field current is the battery via the ignition switch and the warning lamp 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 selfsustaining Alternator Circuitry Warning Lamp • Turn ignition ON, – 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 voltage – equal voltage on both sides of lamp – lamp goes out. Warning Lamp (continued) • If the alternator fails, – Voltage out of diode trio drops – Lamp illuminates from the battery voltage • If the battery fails, – Battery voltage drops – Lamp illuminates from the alternator voltage Inside the Regulator IC1+Ic2 Ic2 Field Current Ic1 Sample Battery Voltage Regulator Circuit • When battery voltage is OK, – D1 conducts – T2 conducts – Less current through T1 collector – T3 turns Off – Field current now reduced Regulator Circuit (continued) • When battery voltage is low, – D1 is Off – T2 is Off – More current flows through T1collector – Transistor T3 turns On – Field current increases