Keysights InfiniiVision X-Series oscilloscopes
offer a broad range of power-related measurements with the power measurements option.
This video is part of a series of several short videos
on specific power supply related measurements.
Here we show a simplified schematic
of a switch mode power supply, along with the list of measurements that can be performed
on the power supply to test and characterize it.
In this video demonstration
we all focus on performing a power quality measurement
on the AC input, which is highlighted in green here
For our demonstration, we'll be using Keysight's
switch mode power supply demo board.
This is the same DUT we use in many of our hands-on workshops around the world.
The first task in making a power quality measurement is to probe the AC input with voltage and current probes.
You'll typically need a high voltage differential probe
and a clamp-on Hall Effect current probe.
This particular power supply demo board has PCB current loop traces built-in to make current probing easy.
When making current measurements on your DUT, however, you will typically need to create your own wire current loops.
Let's start making measurements.
I'll begin with the default setup so we can start everything from scratch.
Next I'll go into the analyze menu,
which, this menu actually you can get to directly with the front panel key-select the power application.
Now that we have the power menu up, this popup shows the various powers measurements
that can be performed with the power option, and we have videos on each of these.
We're going to select the power quality measurement.
The next step is to go into the signals menu.
Now on this menu to see a diagram similar
to the diagram we showed earlier, it gives you hints on how to connect your probes.
We can also assign which channel of the scope
is voltage, in this case we use the default channel one,
current is channel two. We're going to make our measurement based upon two cycles.
And then I will simply press auto setup.
What auto setup does is it provides optimum scaling for the voltage waveform
which is the yellow sinusoidal looking waveform. It's a little distorted from our step down transformer.
The green waveform that's pulsed is the current waveform, which is pretty typical for power supply.
And then the purple waveform is the power waveform. This is created using the scope's waveform math,
it simply multiplies the instantaneous voltage times the instantaneous current to produce the power waveform.
At this point, we're all ready to perform our power quality measurements.
To perform the various power quality measurements, I simply press apply.
And then it automatically turns on all the important measurements including:
power factor, real power, parent power, reactive power, press factor voltage in which case you can see it's about 1.38,
and an ideal sinewave would be about 1.414.
Press factor of current, phase angle, RMS voltage, and the frequency which you can see- this is 60 Hz.
It also supplies full statistics so you can get mean, min, max, and standard deviation.
Now you probably noticed that the statistics window with our
I think we have eight or nine different measurements up there
is covering up part of the waveform. We can move this around, or you can go to transparent dialogues
or you can just simply turn the statistics off and look at the real time updated statistics measurements of power quality.
As mentioned at the beginning of this demonstration, this short video was part of a series of several short videos
on specific power supply related measurements.
To learn more about InfiniiVision X-Series oscilloscopes and how they can help you test to debug your power supplies,
contact your local Keysight authorized distributor and ask for a demonstration.
Thank you.