Control And Display Boards - Lincoln Electric PRO-CUT 55 Service Manual

E-6
INPUT
LINE INPUT
SWITCH RECTIFIER
AIR
PRESSURE
SWITCH
"A"
L
E
A
D
FAN
MOTORS
AUXILIARY
TRANSFORMER

CONTROL AND DISPLAY BOARDS

The control board receives status and analog feed-
back signals from the output board, display board,
power board and various sensors. The processor
interprets these signals, makes decisions and changes
machine mode and output to satisfy the requirements
as defined by the internal software. The control board
THEORY OF OPERATION
FIGURE E.6 – CONTROL AND DISPLAY BOARDS
POWER BOARD
CR 1
RELAY
IGBT
CAPACITOR
R
E
IGBT
C
O
N
N
E
C
IGBT
T
TRANSFORMER
S
W
I
CAPACITOR
T
C
H
IGBT
P
R
O
T
CR 1
E IGBT
RELAY
C
GATE
DRIVE
T
SIGNALS
SIGNAL
I
O
N
SIGNAL
CONTROL BOARD
18/36VAC
A
R
I
E
R
THERMOSTATS
A
L
D
Y O
W
OUTPUT
CONTROL
DISPLAY BOARD
MAIN
TRANSFORMER
CURRENT
TRIGGER & SAFETY
ELECTRODE & TRANSFER
CURRENT FEEDBACK
PILOT ENABLE
ELECTRODE SOLENOID ENABLE
AIR SOLENOID ENABLE
T S
H
A
E
F
R
E
M
T
A
Y
L
regulates the output of the machine by controlling the
IGBT switching times through pulse width modulation
circuitry. See Pulse Width Modulation in this section.
The display board receives commands from the con-
trol board and, via indicator lights, communicates Pro-
Cut 55 status and operating conditions to the user.
WORK
NOZZLE
ELECTRODE
TORCH
CONNECTOR
OUTPUT BOARD
E
L
E
C
T
R
O
D
E
CHOKE
S
O
PILOT
L
TRANSISTOR
E
N
O
I
D
TRIGGER & SAFETY
AIR
SOLENOID
12VAC
24VAC
E-6