15
Initial Checkout Procedure
The following procedure will verify that the MegaPulse 1.2x50-12.3PF-1 500ohm 0.5J tester is working
correctly. We recommend that this procedure be conducted periodically to ensure proper operation of the
tester. The following items are needed to conduct this procedure: A measuring instrument to monitor the
output waveform. Always ensure that the measuring instrument (usually an oscilloscope with a high-
voltage probe) is rated for the voltage involved, and that the frequency response of the instrument and
probe are capable of measuring the output waveform of the MegaPulse 1.2x50-12.3PF-1 500ohm 0.5J
tester. A measuring instrument or probe with a low frequency response will result in erroneous readings
that could be mis-read.
CAUTION
High voltage generated by the MegaPulse tester is exposed during this test. A risk of shock
exists. Exercise care when using the MegaPulse tester.
1.
Connect the tester to a proper source of supply using the included 18 AWG power supply cord.
2. Plug the Output and Return test leads into the jacks on the front panel.
3.
Connect the ends of the test leads to an appropriate measuring instrument (typically an oscilloscope
with a high-voltage probe). Note that the
RETURN
lead is referenced to the chassis ground of the
tester. See
Figure 8
as an example.
4.
Turn the Tester on. Toggle the
POLARITY
switch if necessary so that the
NOR
indicator is lit.
5.
Note that the Voltage meter may indicate that some residual voltage is present on the main storage
capacitor, even when the tester is first turned ON. This is due to inherent charging of the internal
capacitors. Pressing the
TRIGGER
switch will discharge the capacitors (be sure not to touch the
output and return leads when pressing the trigger switch).
6.
Adjust the digital
VOLTAGE
knob to the desire value.
7.
Push the yellow
CHARGE
button. Verify the red
TRIGGER
indicator is now lit.
8.
Adjust the
VOLTAGE
knob so that the front panel LED display is reading a voltage that is suitable
for the measuring instrument that is being used. Push the red
TRIGGER
button, and view the
resulting impulse waveform on the measuring instrument.
9.
Note that the peak amplitude of the measured output waveform is proportional to the voltage that is
read of the front panel of the MegaPulse, but it will always be somewhat lower. This is because the
meter on the MegaPulse is measuring the voltage on the main impulse storage capacitor. This
voltage will intentionally dissipate to some extent before reaching the output leads.
10. Repeat steps 5 through 8, except this time toggle the
POLARITY
switch so that the
REV
indicator
is lit. Note that the impulse waveform will now be a negative pulse, so it will probably be
necessary to make adjustments to the measuring instrument to get a proper reading.
11. Adjust the digital
VOLTAGE
knob to “00000”. Turn the rear-panel power switch OFF.
Summary of Contents for MegaPulse 1.2x50-12.3PF-1
Page 1: ...MegaPulse IMPULSE TESTER 1 2x50 12 3PF 1 500ohm 0 5J Instruction Manual...
Page 3: ......
Page 5: ...1...
Page 12: ...8 Figure 5 Test Voltages and Tolerance from IEC 60255 5...
Page 29: ...25 Figure A 5 Breakdown as the voltage is rising...
Page 30: ...26 Figure A 6 Dieletric breakdown immediately after Vpeak...
Page 31: ...27 Figure A 7 Dielectric breakdown after Vpeak delayed breakdown...
