Lincoln Electric VANTAGE SVM178-B Service Manual page 181

TABLE OF CONTENTS-THEORY OF OPERATION SECTION
E-1
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-1
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-2
Battery, Starter, Engine, Rotor, Stator, Pull Coil Board and Peripheral Board – Engine Protection . . . . . .E-2
Weld Windings, Rectifier, Power Modules and Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-3
Weld Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-4
Insulated Gate Bipolar Transistor (IGBT) Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-5
Pulse Width Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-6
Chopper Technology Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-7
ENGINE
ALTERNATOR
+12 VDC
STARTER
RUN
OIL
RUN/STOP
PRESSURE
SWITCH
ON
ENGINE
SENSORS
START
BUTTON
+12 VDC
RUN
+
BATTERY
PERIPHERAL
PCB
PULL
COIL
PCB
PULL
FUEL
IDLER
SOLENOID
SOLENOID
FIGURE E.1 BLOCK LOGIC DIAGRAM
D
L
E
W
MECHANICAL
25•
(COLD)
ROTATION
SLIP
RINGS
STATOR
WATER
TEMP.
AUXILIARY
160VDC
FLASHING
120VAC
(Not on EURO Machnes)
PULL
LOW IDLER SIGNAL (TO SUPPLY PULL VOLTS)
HOLD VOLTS FROM CONTROL PCB
* On some codes the Peripheral Board, Pull Coil Board, Idler Solenoid & Fuel Solenoid are
replaced by an Electronic Governor Control module and components. See Wiring Diagram.
VANTAGE® 500
RECTIFIER
THREE-PHASE
+ +
_ _
W
I
N
D
I
+12VDC
G
RUN
ROTOR
AUX. POWER
USE SENSING
42 VAC and 120VAC
to 14 Pin Amphenol
for Wire Feeder
(No 120 VAC on EURO Models)
WINDINGS
AC RECEPTACLES
Various combinations of
1Ø and 3Ø Outputs.
See Techincal Specs.
120 VAC
RECEPTACLES
+ +
SHUNT
TO WELD
CONTROL
BOARD TO
CONTROL
PCB
IGBT
IGBT
CHOKE
__ __
R4-50•
2-POWER MODULES
PWM PWM
SIGNAL SIGNAL
WELD
CONTROL
VOLTMETER
BOARD
AMMETER
ARC OUTPUT MODE
CONTROL CONTROL SELECT
SWITCH
E-1