Lincoln Electric INVERTEC V300-PRO SVM105-B Service Manual page 23

Section E-1
- THEORY OF OPERATION SECTION -
Theory of Operation ...............................................................................................Section E
Power Supply Operation ......................................................................................E-2
Pre Charge and Protection Circuitry ....................................................................E-3
Switch Board and Main Transformer....................................................................E-4
Control and Output Circuitry ................................................................................E-5
Field Effect Transistor (FET) Operation ...............................................................E-6
Pulse Width Modulation .......................................................................................E-7
Protective Circuits ................................................................................................E-8
1ø OR 3ø DETETCTION (H5)
INPUT
LINE
RECTIFIER
SWITCH
1
AC1
2 AC2
3 AC3
3A
A-LEAD
24VDC
AUXILIARY
FAN
TRANSFORMER
18VAC
24VAC
TO
WIREFEEDER
TABLE OF CONTENTS
FIGURE E.1 – V300-PRO BLOCK LOGIC DIAGRAM
POWER SWITCH
SECTIONS
20KHZ
LEFT SWITCH BOARD
FET MODULES
CAP
FET MODULES
PRE-CHARGE
DRIVER
BOARD
CR1
PROTECTION
PULSE
BOARD
TRAIN
CR2
PRE-CHARGE
RIGHT SWITCH BOARD
2ND STEP PWM
FET MODULES
CAP
POWERBOARD
FET MODULES
<1 VDC
LOCAL
METER MODE
REMOTE
1ST STEP PWM VOLTAGE
15VDC-CONTROL BOARD FUNCTION VOLTAGE
24VAC-THERMOSTATS-GUN TRIGGERING
V300-PRO
MAIN
TRANSFORMER
TOP
CURRENT
TRANSFORMER
CONTROL
BOARD
BOTTOM
Y-Y FEEDBACK
TOP
VOLTAGE FEEDBACK
POT
POT
CURRENT FEEDBACK-PROTECTION
Section E-1
RECTIFIER
CHOKE
HEATSINK
1 DIODE
5 DIODES
5 DIODES
1 DIODE
CHOKE
CHOKE
SHUNT