Typical Scr Gate Voltage Waveform - Lincoln Electric SQUARE WAVE TIG 255 SVM100-A Service Manual

F-37

TYPICAL SCR GATE VOLTAGE WAVEFORM

HIGH VOLTAGE / HIGH FREQUENCY can damage test equipment.
• Perform all voltage and waveform checks with high frequency circuit OFF.
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This is the typical SCR gate pulse 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.
SQUARE WAVE TIG 255
TROUBLESHOOTING & REPAIR
CAUTION
2 volts
CH1
5ms
SCOPE SETTINGS
Volts/Div..................................2 V/Div.
Horizontal Sweep .................5 ms/Div.
Coupling .........................................DC
Trigger .....................................Internal
0 volts