Abnormal Open Circuit Voltage Waveform - Lincoln Electric SVM189-B Service Manual

F-24

ABNORMAL OPEN CIRCUIT VOLTAGE WAVEFORM

10Volts
TROUBLESHOOTING & REPAIR
This is NOT the typical voltage wave-
form. The output capacitor was dis-
connected from the circuit. Note the
increased ripple in the waveform. This
condition simulates the faulty output
filter capacitor. Each vertical division
represents 10 volts and that each hor-
izontal division represents 20 millisec-
onds in time.
Note: Scope probes connect at the
machine output terminals. Positive
probe to (+) terminal, negative probe
to (-) terminal.
SCOPE SETTINGS
Volts/Div.....................10V/Div.
Horizontal Sweep ...20 ms/Div.
Coupling.............................DC
Trigger.........................Internal
COMPACT WIRE WELDERS
F-24
C1
0 volts
20ms