MUFFLER 4N3573 - Caterpillar

The field winding uses DC voltage to create a magnetic field. The magnetic field is used to magnetize the rotor. The stator is a stationary component that surrounds the rotor. When the rotor rotates voltage is produced. The stator will then send the voltage to the rectifier. The rectifier changes the AC voltage into DC voltage. Part of the DC voltage returns to the field winding in order to maintain the magnetic field. The remainder of the DC voltage is supplied to the battery. Electrical components on the machine will then receive the voltage from the battery. The regulator limits the DC voltage at the battery terminals to 28 1 volts by controlling the current in the field winding.Alternator Operation Schematics
Illustration 1 g00866883
Electrical schematic of the N3 series alternator (35 amperes)B- - Frame to battery groundB+ - Alternator to battery positive terminalD+ - Output for the excitation circuit and regulator inputD- - Ground for the alternator and regulatorDF - Alternator output and regulator inputG - Field windingR - Auxiliary terminalU - Stator windingV - Stator windingW - Stator winding
Illustration 2 g00866887
Electrical schematic of the N3 series alternator (50 amperes) (1) Diodes for protection against load dumpB- - Frame to battery groundB+ - Alternator to battery positive terminalD+ - Output for the excitation circuit and regulator inputD- - Ground for the alternator and regulatorDF - Alternator output and regulator inputG - Field windingR - Auxiliary terminalU - Stator windingV - Stator windingW - Stator windingNote: The "R" terminal may be used by one of the following components:
Charge indicator
Tachometer
Hour meter
Electronic control moduleIllustrations 1 and 2 show the electrical schematics for the N3 series alternators.The alternator has two circuits: the charging circuit and the excitation circuit. The charging circuit functions during normal operation. The excitation circuit functions during normal operation and during start-up. An independent circuit exists for each phase of the stator. Phases are noted as "U", "V", and "W". The 50 amp alternator has two extra diodes. Diodes are connected to the neutral point of the stator. Diodes also add extra current to the output. However, the 35 ampere alternator lacks the extra diodes. The descriptions that follow show the N3 series alternator (35 ampere).Charging Circuit
The charging circuit supplies current to the battery and to the electrical systems during normal operation. Stator windings in the alternator generate three-phase AC voltage. Positive diodes and the negative diodes change the AC voltage into DC voltage. DC voltage allows the current to flow to the battery terminals.
Illustration 3 g00825118
Charging circuit with phase angle of 120°The flow of current at a 120° phase angle is shown in Illustration 3. The polarity for the stator winding is described below:
Positive at the output of winding "U"
Zero at the output of