Lincoln Electric RANGER 250 SVM150-A Service Manual page 43

Section E-1
-THEORY OF OPERATION SECTION-
Theory of Operation .............................................................................................................Section E
General Description ..............................................................................................................E-2
Battery, Engine, Rotor, Stator and Engine Protection ...........................................................E-2
Weld Windings, Rectifier, Power Module and Feedback.......................................................E-3
Analog Power Board and Control Board ...............................................................................E-4
Insulated Gate Bipolar Transistor (IGBT) Operation .............................................................E-5
Pulse Width Modulation .........................................................................................................E-6
Chopper Technology Fundamentals ......................................................................................E-7
GAS
ENGINE
STARTER
FLYWHEEL
ALTERNATOR
OIL
PRESSURE
SWITCH
SOL
I
D
BATTERY
L
RUN/STOP
E
SWITCH
R
BATTERY
BOARD
TABLE OF CONTENTS
FIGURE E.1 - RANGER 250 BLOCK LOGIC DIAGRAM
MECHANICAL
ROTATION
SLIP
RINGS
STATOR
FIELD
WINDING
4
2
V
A
C
TO CONTROL
BOARD
RECEPTACLE
RANGER 250
THREE-PHASE
RECTIFIER
+
4
0
D W
TO
L I
1
E N
0
W D
0
I
N V
G
D
C
ANALOG
POWER
ROTOR BOARD
AUXILIARY WIRE FEED
WINDINGS PWR WNDG
4
2
V
A
2 1
C
4 2
0 0
AMPHENOL
V V
A A
C C
240VAC 120VAC
RECEPTACLE
Section E-1
TERMINAL
TO
CONTROL
BOARD
ELECTRODE
TERMINAL
IGBT
CHOKE
SHUNT
POWER MODULE
2 S
FROM
0 I
P
TOROID
G
W
CURRENT
V N
M
SENSOR
D A
C L
S
CONTROL
BOARD
REGULATED VOLTAGES
ARC OUTPUT MODE
CONTROL CONTROL SELECTOR
WORK
__ __
+
F
E
E
D
B
A
C
K