Lincoln Electric LN-15 WIRE FEEDER SVM166-A Service Manual page 37

E-5
ELECTRODE
INPUT VOLTAGE
TOROID
ASSEMBLY
FULL
WAVE
BRIDGE
WORK
SENSING
LEAD
"WORK" VOLTAGE FEEDBACK #21
DISPLAY BOARD
The Display Board provides information to the user
through digital displays and LED's. The Display Board
communicates with the Feed Head Board via the SPI
Bus cable.
The wire feed speed display shows the rate that the
LN-15 will feed wire during the welding process. The
wire feed speed is calibrated to within +/-2%.
always displays the preset WFS.
The arc voltage display shows the average actual arc
voltage during the welding process. When welding
ceases the average arc voltage will continue to be
shown for 5 seconds. When not welding the display
show "----". The voltage is calibrated to +/-2% over a
range of 10 to 45VDC. A negative "-" will be automat-
ically displayed when the LN-15 is configured for elec-
trode negative processes.
All of the LEDs will briefly light when the machine is
first turned on.
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
THEORY OF OPERATION
FIGURE E.5 – DISPLAY BOARD
CONTACTOR
ON/OFF
FEED HEAD
SWITCH
BOARD SUPPLY
BOOST
POWER
SUPPLY
MOV
BOARD
DRIVE MOTOR
SUPPLY
GAS
SOLENOID
"ELECTRODE"
FEEDBACK
VOLTAGE #67
FEED HEAD
CONTROL BOARD
TRIGGER
COLD
WIRE
INPUT &
INCH
FEED
PROCEDURE
SWITCH
SPEED
CONTROL
It
LN-15
WELDING
FEED
PLATE
M
O
HALL
T
O EFFECT
R
MODULE
ARMATURE
RPM FEEDBACK
SPI COMMUNICATIONS
SHIELDED CABLE
TRIGGER
DISPLAY
INTERLOCK
BOARD
SWITCH
E-5