Weld Windings, Rectifier, Chopper Module And Feedback - Lincoln Electric Cross Country 300 Service Manual

LINCOLN ELECTRIC
Figure E.3 – Weld windings, rectifier, chopper module and feedback
GLOW PLUG GLOW PLUG
SWITCH SWITCH
ENGINE ENGINE
ALTERNATOR ALTERNATOR A
START START
SHUTDOWN SHUTDOWN
BUTTON BUTTON
STARTER STARTER
SOLENOID SOLENOID
12V STUD 12V STUD
RUN
RUN
SWITCH SWITCH
+ +
BATTERY BATTERY
– –
Weld Windings, Rectifier, Chopper Module and Feedback
The three-phase stator weld windings are connected to a three-phase rectifier bridge. The resultant DC
voltage is applied to four paralleled capacitors incorporated within the chopper module. These capacitors
function as filters and also as power supplies for the IGBT's. See IGBT Operation in this section. The IGBT's
act as high-speed switches operating at 20Khz. These devices are switched on and off by the weld control
board through pulse width modulation circuitry. See Pulse Width Modulation in this section.
This "chopped" DC output is applied through choke coil and a shunt to the welding output terminals. The
choke functions as a current filter. Free-wheeling diodes are incorporated in the power module to provide
a current path for the stored energy in the choke when the IGBTs are turned off. See Chopper Technology
in this section.
Output voltage and current feedback information is fed to the weld control board. This information is
sensed from the output terminal circuits and the shunt.
STATOR STATOR
MECHANICAL MECHANICAL
COUPLING COUPLING
ENGINE ENGINE
ENGINE SENSOR ENGINE SENSOR
OIL PRESSURE OIL PRESSURE
IDLE IDLE
TEMPERATURE TEMPERATURE
SOLENOID SOLENOID
SOLENOID SOLENOID
ROTOR ROTOR
ENGINE PROTECTION / ENGINE PROTECTION /
FLASHING FLASHING
IDLE CONTROL BOARD IDLE CONTROL BOARD
FUEL LEVEL FUEL LEVEL
DASH BOARD DASH BOARD
SENSOR SENSOR
GAUGE GAUGE
–
RECTIFIER
BRIDGE
ROTOR ROTOR
SLIP RINGS SLIP RINGS
+ + – –
IDLE IDLE
SWITCH SWITCH
AUX. POWER AUX. POWER
RECEPTACLES RECEPTACLES
LOW IDLE COMMAND LOW IDLE COMMAND
REMOTE REMOTE
AMPHENOL AMPHENOL AMPHENOL
Cross Country™ 300 Service Manual
+
CHOPPER
CHOKE
BD IGBT
WELD CON WELD CONTROL BOARD NTROL BOARD
ARC ARC
OUTPUT OUTPUT
CONTROL CONTROL CONTROL CONTROL L
WELD WELD WELD WELD
AMPMETE AMPMETER R
VOLT METER VOLT METER
+
POSITIVE
OUTPUT TERMINAL
SHUNT
–
NEGATIVE CC
OUTPUT TERMINAL
–
NEGATIVE CV
OUTPUT TERMINAL
MODE MODE
SWITCH SWITCH
6