Theory Of Operation - Lincoln Electric BULLDOG SVM208-A Service Manual

E-4
FIGURE E.4 - WELD WINDING, REACTOR AND AUXILIARY POWER OVERCURRENT PROTECTION
ENGINE
MAGNETO
WELD WINDING AND REACTOR
The AC voltage developed in the stator weld winding is
delivered, through the reactor, to the machine output
terminals. The BULLDOG 140 provides the user up to
125 amps of constant current AC welding for stick elec-
trodes. The reactor stores energy, and this energy is
released into the welding arc when the AC voltage
passes through the zero point. In this manner the
reactor enhances and stabilizes the AC welding arc.
The reactor is designed to provide optimum welding
characteristics when used with the recommended elec-
trodes.

THEORY OF OPERATION

MECHANICAL
ROTATION
ROTOR
SLIP
RINGS
CAPACITOR
RHEOSTAT
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
BULLDOG® 140
REACTOR
STATOR
ROTOR
STATOR
115 AND 230VAC
RECEPTACLES
BRIDGE
AUXILIARY POWER
OVERCURRENT PROTECTION
The 4000 watt auxiliary power winding and circuitry is
protected from an overload condition by two 20 amp
circuit breakers. The circuit breakers are located below
the output receptacles. They can be manually reset.
E-4
OUTPUT
TERMINALS