Abnormal Open Circuit Dc Weld Voltage Waveform - Lincoln Electric RANGER 3PHASE SVM207-A Service Manual

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ABNORMAL OPEN CIRCUIT DC WELD VOLTAGE WAVEFORM

HIGH IDLE - NO LOAD - OUTPUT CONTROL AT MAXIMUM
TROUBLESHOOTING AND REPAIR
ONE OUTPUT DIODE NOT FUNCTIONING
50 volts
This is NOT the typical DC (+) output
voltage waveform. One output diode
is not functioning. Note the "gap" in
the waveform. One output diode was
disconnected to simulate an open or
nonfunctioning output diode.
vertical division represents 50 volts
and each horizontal division repre-
sents 5 milliseconds in time.
Note: Scope probes connected at
machine 115VAC receptacle.
SCOPE SETTINGS
Volts/Div.....................50V/Div.
Horizontal Sweep .....5 ms/Div.
Coupling.............................DC
Trigger.........................Internal
RANGER® 3 PHASE
CH1
0 volts
5 ms
Each
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