Lincoln Electric SVM188-A Service Manual page 76

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TYPICAL SCR GATE VOLTAGE WAVEFORM
TROUBLESHOOTING AND REPAIR
CONSTANT VOLTAGE INNERSHIELD
MAXIMUM OUTPUT SETTING – NO LOAD
2 V
This is the typical DC open circuit
voltage waveform. The machine was
in an open circuit condition (no load)
and operating properly. Note that
each vertical division represents 2
volts and that each horizontal division
represents 5 milliseconds in time.
Note: Scope probes connected at
SCR gate and cathode: (+) probe to
gate, (-) probe to cathode.
SCOPE SETTINGS
Volts/Div .......................2V/Div.
Horizontal Sweep .....5 ms/Div.
Coupling.............................DC
Trigger .........................Internal
DC-600
0 volts
5ms
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