Lincoln Electric SVM189-B Service Manual page 49

E-3
CIRCUIT
BREAKER
INPUT
RECEPTACLE
INPUT LINE VOLTAGE, FAN MOTOR
& MAIN TRANSFORMER
A circuit breaker is incorporated in the circuit to protect
the unit from current overloads.
The main transformer receives the primary voltage
from the Control Board and changes that high voltage
and low current input power to a low voltage and high
current output suitable for welding.
The fan motor is rated for the same AC Voltage as the
welder and should run whenever the machine is Power
Switch is turned ON.
THEORY OF OPERATION
FIGURE E.3 — INPUT POWER CIRCUITS
ARC
TRIGGER
VOLTAGE
RECEPTACLE
CONTROL
CONTROL
BOARD
LINE
SWITCH
FAN
MOTOR
MAIN
TRANSFORMER
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
COMPACT WIRE WELDERS
WIRE
SPEED
CONTROL
GAS
SOLENOID
WIRE
FEED
MOTOR
VOLTAGE FEEDBACK &
MOTOR POWER
+
CHOKE
MAIN
BRIDGE
E-3
+
OUTPUT
TERMINALS
-