Filter
Top Products
Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC
Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC
WELD WINDINGS, RECTIFIER,
POWER MODULE AND FEEDBACK
The three-phase stator weld windings are connected to
a three-phase rectifier bridge. The resultant DC volt-
age is applied to parallel capacitors incorporated with-
in the power module. These capacitors function as fil-
ters and also as power supplies for the IGBT. See
IGBT Operation in this section. The IGBT acts as a
high-speed switch operating at 20KHZ. This device is
switched on and off by the control board through
pulsewidth modulation circuitry. See Pulse Width
Modulation in this section. This “chopped” DC output
is applied through a choke coil and shunt to the weld-
ing 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 chokes when the IGBT is turned off. See
Chopper Technology in this section.
Output voltage and current feedback information is fed
to the control board. This information is sensed from
the output terminal circuits and the shunt.
THEORY OF OPERATION
E-3 E-3
RANGER 250
FIGURE E.3 – WELD WINDINGS, RECTIFIER, POWER MODULE AND FEEDBACK
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
ENGINE
CONTROL
BOARD
ROTOR
STATOR
BATTERY
BOARD
BATTERY
CHOKE
IGBT
MECHANICAL
ROTATIO N
STARTER
I
D
L
E
R
ARC
CONTROL
OUTPUT
CONTROL
MODE
SELECTOR
POWER MODULE
THREE-PHASE
RECTIFIER
WORK
TERMINAL
ELECTRODE
TERMINAL
+
120VAC
RECEPTACLE
240VAC
RECEPTACLE
SLIP
RINGS
TO
CONTROL
BOARD
GAS
OIL
PRESSURE
SWITCH
RUN/STOP
SWITCH
FLYWHEEL
ALTERNATOR
TO CONTROL
BOARD
AMPHENOL
4
2
V
A
C
FIELD
WINDING
AUXILIARY
WINDINGS
WIRE FEED
PWR WNDG
4
2
V
A
C
2
4
0
V
A
C
1
2
0
V
A
C
W
E
L
D W
I
N
D
I
N
G
+
ANALOG
POWER
BOARD
2
0
V
D
C
4
0
TO
1
0
0
V
D
C
FROM
TOROID
CURRENT
SENSOR
SHUNT
F
E
E
D
B
A
C
K
SOL
____
REGULATED VOLTAGES
P
W
M
S
I
G
N
A
L
S