Theory of operation, Control and display boards – Lincoln Electric PRO-CUT 55 SVM140-A User Manual
Page 33
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
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.
THEORY OF OPERATION
E-6
E-6
PRO-CUT 55
FIGURE E.6 – CONTROL AND DISPLAY BOARDS
INPUT
LINE
SWITCH
INPUT
RECTIFIER
FAN
MOTORS
"A"
L
E
A
D
AUXILIARY
TRANSFORMER
OUTPUT
CONTROL
AIR
PRESSURE
SWITCH
P
R
O
T
E
C
T
O
N
I
SIGNAL
CR 1
DRIVE
SIGNAL
RELAY
IGBT
GATE
SIGNALS
R
E
A
D
Y
A
I
R
L
O
W
T
H
E
R
M
A
L
S
A
F
E
Y
T
TRIGGER & SAFETY
ELECTRODE & TRANSFER
CURRENT FEEDBACK
PILOT ENABLE
ELECTRODE SOLENOID ENABLE
AIR SOLENOID ENABLE
AIR
SOLENOID
TRIGGER & SAFETY
E
L
E
C
T
R
O
D
E
S
O
L
E
N
O
I
D
TORCH
CONNECTOR
ELECTRODE
NOZZLE
WORK
R
E
C
O
N
N
E
C
T
S
W
T
C
H
I
POWER BOARD
CR 1
RELAY
IGBT
IGBT
IGBT
IGBT
CAPACITOR
CAPACITOR
CURRENT
TRANSFORMER
CONTROL BOARD
DISPLAY BOARD
18/36VAC
12VAC
24VAC
MAIN
TRANSFORMER
OUTPUT
BOARD
CHOKE
PILOT
TRANSISTOR
THERMOSTATS