Hitachi ZW180 Technical Manual page 164

Alternator Operation
•
The alternator consists of field coil FC, stator coil
SC and diode D.
•
At the beginning, no current is flowing through
field coil FC. When the rotor starts rotating,
alternate current is generated in stator coil SC by
the rotor remanent magnetism.
•
When current flows through field coil FC, the rotor
is further magnetized so that the generating
voltage increases. Thereby, current flowing
through field coil FC increases. Therefore,
generating voltage increases further and the
batteries start charging.
SYSTEM / Electrical System
T2-4-14
Operation of Regulator
•
The regulator is an IC chip, which maintains
generating voltage at a constant level.
•
When generating voltage exceeds the set-voltage,
the regulator decreases current through field coil
FC. This decreases generating voltage of stator
coil SC.
•
When generating voltage becomes lower than the
set-voltage, the regulator increases current
through field coil FC. This increases generating
voltage of stator coil SC.
•
The above operation is repeated so that the
alternator generating voltage is kept constant.