Charging System - Mitsubishi MOTORS Space Runner 1998 Workshop Manual

16-2

CHARGING SYSTEM

GENERAL INFORMATION
The charging system uses the alternator output
to keep the battery charged at a constant level
under various electrical loads.
Voltage
Approx. 14.4 V
Time
When the ignition switch is turned on, current flows
in the field coil and initial excitation of the field
coil occurs.
When the stator coil begins to generate power after
the engine is started, the field coil is excited by
the output current of the stator coil.
The alternator output voltage rises as the field
current increases and it falls as the field current
decreases. When the battery voltage (alternator
S terminal voltage) reaches a regulated voltage
SYSTEM DIAGRAM
<4G9>
Stator coil
Field coil
ENGINE ELECTRICAL -
OPERATION
Rotation of the excited field coil generates AC voltage in
the stator.
This alternating current is rectified through diodes to DC
voltage having a waveform shown in the illustration at left.
The average output voltage fluctuates slightly with the
alternator load condition.
B
G
S
Voltage
L
regulator
FR
Charging System
of approx. 14.4 V, the field current is cut off. When
the battery voltage drops below the regulated
voltage, the voltage regulator regulates the output
voltage to a constant level by controlling the field
current.
In addition, when the field current is constant, the
alternator output voltage rises as the engine speed
increases.
Engine-ECU
+
Ignition
switch
Charging
warning lamp
-
Battery