Lincoln Electric RANGER SVM148-B Service Manual page 58

E-5
FIGURE E.5 – OUTPUT BRIDGE, CHOKE, POLARITY SWITCH, OUTPUT CONTACTOR
RANGER 300 DLX
BY-PASS
BOARD
42VAC
115VAC
6 PIN
14 PIN
AMPHENOL
AMPHENOL
OUTPUT BRIDGE, CHOKE,
POLARITY SWITCH, OUTPUT
CONTACTOR AND OUTPUT
TERMINALS
The AC voltage developed in the stator weld winding
is delivered, through the reactor and range switch, to
the output bridge and polarity switch.
upon the setting of the polarity switch, either AC volt-
age or DC voltage is delivered to the output terminals.
If AC output is selected, the current path is from the
stator weld winding through the reactor, range switch,
and polarity switch; through the output contactor to
the output terminals. If a DC output is called for, the
current path is through the output rectifier bridge,
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
THEORY OF OPERATION
AND OUTPUT TERMINALS
SHUTDOWN
SOLENOID
GLOW PLUGS
ENGINE
MECHANICAL
ROTATION
STARTER
MOTOR
IDLER
SOLENOID
ALTERNATOR
BATTERY
CONTACTOR CLOSURE
OUTPUT
CONTROL
REMOTE
SWITCH
Depending
RANGER 300 D AND 300 DLX
RANGE
SWITCH
AC
OUTPUT
RECTIFIER
BRIDGE
AC
REACTOR
STATOR
ROTOR
ROTOR
SLIP
RINGS
OIL &
WATER
SENSORS
FIELD
BRIDGE
PRINTED
CIRCUIT
BOARD
FIELD
CAPACITOR
where the AC voltage is rectified to a DC voltage; and
then to the choke, where the DC output is filtered. The
filtered DC current path is through the polarity switch
and output contactor to the output terminals.
When a CV (constant voltage) is desired, the reactor is
passed by. The range switch applies a lower AC volt-
age to the rectifier bridge. The DC output of the bridge
is filtered and "stiffened" by the capacitors. This lower
but "stiffer" DC output is passed through the tapped
portion of the choke, the polarity switch, and output
contactor to the output terminals.
In the Ranger 300DLX machines, the output contactor
is in series with the electrode terminal and must be
energized (closed) to provide welding voltage at the
output terminals.
WORK
TERMINAL
CHOKE
PART OF
RANGE
SWITCH
CAPACITORS
ELECTRODE
cv
TERMINAL
output
contactor
115 & 230VAC
RECEPTACLES
CONTACTOR CLOSURE
E-5