Description & Operation

The generator is a conventional rotating field, 3-phase, self-rectifying type. System is equipped with Integrated Circuit (IC) voltage regulator. When charge indicator light voltage and generator output voltage are about equal, charge indicator light goes out. Generator rotates clockwise as viewed from pulley side. See GENERATOR APPLICATION .

The generator has a built-in regulator with diagnostic functions and voltage regulating functions, such as the following:

1. VOLTAGE REGULATION
   
   The On-Off operation of transistor TR₁ connects and disconnects the field current circuit which provides a constant output voltage level. See Fig 1.
2. DIAGNOSIS WARNING
   
   When any of the following problems occur the charge lamp illuminates:

   • No voltage generation
     
     Brush wear exceeds specified wear limits, field coil circuit is broken, etc.
   • Excessive output
     
     Output voltage is greater than 16 volts (approx.)
   • Terminal B disconnection
     
     Harness is disconnected from alternator terminal B.
   • Terminal S disconnection
     
     Harness is disconnected from alternator terminal S. In this case, voltage is slightly greater than specified regulated voltage; however, voltage regulation is still controlled and the battery is prevented from overcharging.

Fig 1: Generator Circuit Diagram

Courtesy of SUBARU OF AMERICA, INC.