Lincoln Electric OUTBACK SVM204-A Service Manual page 39

E-5
OIL LEVEL
OIL INDICATOR
LEVEL
MODULE
(KOHLER)
OIL LEVEL
SWITCH
IGNITION
/
STARTER
SOLENOID
10 AMP
FUSE
OFF
AUTO
HIGH
_ _
+ +
START
BATTERY
GENERATING POWER
Flashing
When the engine is running, power from the engine
charging system is stabilized, and then applied to the
rotor brushes through a series of PC board mounted
current limiting resistors and a "flashing" diode.
Building Output
The flashing current produces a weak magnetic field in
the rotor, which is coupled to the now running engine.
This rotating magnetic field begins to generate AC out-
put from all of the stator windings. Output from the
exciter winding is rectified by a diode bridge, filtered by
a capacitor, controlled by circuitry on the PC board,
and fed back into the rotating field winding, making the
magnetic field stronger. This stronger magnetic field
then produces higher voltage from the stator windings,
which feeds back to the rotor, making its magnetic field
even stronger.
This process of strengthening the magnetic field
through feedback from the exciter winding continues to
increase the output of the main generator. If the output
control is set to maximum and the idle switch is in the
THEORY OF OPERATION
FIGURE E.5 - GENERATING POWER
AUXIIARY WINDINGS
SLIP
_ +
RINGS
ENGINE ROTOR
BRUSHES
EXCITER
IDLE
ALTERNATOR WINDING
SOLENOID
ENGINE
SHUTDOWN
RELAY
HOUR
METER
FIELD / CONTROL PC BOARD
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
OUTBACK® 185
CURRENT
120 VAC RECEPTACLES
SENSOR
REACTOR
STATOR
WELD
WINDINGS
BOOST
WINDING
AUTOMATIC OUTPUT
IDLER CONTROL CIRCUIT
CIRCUIT
"high" position, all of the windings should be putting out
maximum voltage almost immediately. The rotor field
voltage is now considerably higher than the flashing
voltage that was used to start the generating process.
The "flashing" diode on the control PC board blocks
that higher field voltage from intruding into the 12VDC
battery system.
AC Output
The generator is now producing normal AC power from
all four of the windings. These windings consist of two
64 VAC weld windings, a 120/240 VAC auxiliary power
winding, and an 82 VAC excitation winding.
240 VAC
RECEPTACLE
CB1 CB3
CB2 CB4
+
CHOKE
OUTPUT
OUTPUT
RECTIFIER
STUDS
(2 PHASE)
OUTPUT
CONTROL
E-5