Lincoln Electric PRECISION TIG 375 Service Manual page 87

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TYPICAL AC VOLTAGE WAVEFORM - MACHINE LOADED TO 50 AMPS
HIGH VOLTAGE/ HIGH FREQUENCY can damage test equipment.
Perform all voltage and waveform checks with high frequency circuit OFF.
Perform High Frequency Disable Procedure.
TROUBLESHOOTING & REPAIR
AC - TIG MODE
20V
AC BALANCE CONTROL IN "AUTO"
This is the typical DC (+) output voltage
waveform generated from a properly
operating machine. Note that each ver-
tical division represents 20 volts and
that each horizontal division represents
5 milliseconds in time.
NOTE: Scope probes connected at
machine output terminals: (+) probe to
electrode, (-) probe to work.
SCOPE SETTINGS
Volts/Div......................20V/Div.
Horizontal Sweep......5 ms/Div.
Coupling..............................DC
Trigger..........................Internal
PRECISION TIG 375
0V
5 ms
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