Lincoln Electric BULLDOG SVM208-A - Manual (Page 47)

THEORY OF OPERATION E-3 E-3
BULLDOG® 140
ROTOR FIELD FEEDBACK AND
AUXILIARY POWER
The AC voltage developed in the field winding is fed to
the full wave bridge. The DC output of the bridge is fil-
tered by the field capacitor and controlled by the output
rheostat.
This filtered and controlled feedback voltage is fed to
the rotor winding via the brush and slip ring configura-
tion. As the feedback voltage is increased or de -
creased, the outputs of the weld and auxiliary windings
are likewise increased or decreased.
FIGURE E.3 - ROTOR FIELD FEEDBACK AND AUXILIARY POWER
When full field voltage is applied to the rotor and the
engine is running at high speed (3700 RPM), a 230
VAC voltage is developed in the stator auxiliary wind-
ing. This winding is tapped to provide 115 VAC. The
two voltages (115 VAC and 230 VAC) are connected to
the appropriate receptacles and offer 5500 watts (total)
of AC power.
ENGINE
STATOR
STATOR
ROTOR
REACTOR
BRIDGE
CAPACITOR
RHEOSTAT
115 AND 230VAC
RECEPTACLES
OUTPUT
TERMINALS
ROTATION
MECHANICAL
SLIP
RINGS
ROTOR
MAGNETO
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
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