Theory Of Operation - Lincoln Electric IDEALARC SP-250 Service Manual

- THEORY OF OPERATION SECTION -
THEORY OF OPERATION SECTION ...................... Section E
Power Supply Operation ........................................E-1 - E-3
Input Line Voltage and Main Transformer ...................E-1
Output Rectification and Feedback Control ................E-2
Constant Voltage Output .............................................E-3
Wire Drive Motor and Feedback .................................E-4
Thermal Protection ...........................................................E-5
SCR Operation ............................................................... E-6
LCD
DISPLAY
KEYPAD
MAIN
LINE
TRANSFORMER
SWITCH
RECONNECT
FAN
MOTORS

THEORY OF OPERATION

TABLE OF CONTENTS
PIEZO GAS
ALARM SOLENOID
CONTROL BOARD
G
A
T
E
S
I
G
N
A
L
C
A
P
A
C
SCR I
RECTIFIER T
O
R
S
SHUNT
Figure E.1 -Block Logic Diagram
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
IDEALARC SP-250
WIRE
DRIVE
MOTOR
TACH
GUN TRIGGER AND THUMB SWITCH
FEEDBACK
POSITIVE
TERMINAL
CHOKE
F
E
E
D
B
A
C
K
NEGATIVE
TERMINAL