Hi. My name is Bob Zolo of Agilent Technologies. Today I’d like to show you this instrument
called the N6705B DC Power Analyzer. The DC Power Analyzer is an interesting instrument
and it’s unique in the marketplace. Its mission is to increase the productivity of
the R&D engineer and it does that by combining multiple instrument functions into a single
package. So for example in this instrument, you could have up to four DC power supplies
plus a voltmeter, ammeter, oscilloscope, data logger, and arbitrary waveform generator.
And all of the capability is accessed through the front panel of the instrument, although
it is a programmable instrument as well over LAN, USB and GPIB. Today I’d like to show
you some of the more basic capabilities of the power supply, the voltmeter, the ammeter,
and the oscilloscope, so let’s get started. My DUT for today’s demonstration will be
this 12-volt fan. What I’m going to do is I’m going to power it up using the power
supply. So let’s get started. The main screen here you can see these four colored squares.
Each corresponds to the four outputs of the DC power supplies. But I only need one output
since the fan requires 12 volts, one output. So let me zoom in on Channel 1 where you can
see when I hit the meter button, a large display of Channel 1 and a summary of the other channels.
We’ll only be using Channel 1. The first thing I need to do is I need to program Channel 1
to 12 volts and about 1 amp to power up the fan. So let me begin by entering the values here.
I can either turn the voltage knob to raise the voltage or I can directly enter
it using the keypad, which is what I’m going to do. So I just set it there to 12 volts.
Now I move down to the current and I enter 1 for current. The output is turned off right
now and the meter of course is showing no current flowing or no power flowing. When
I turn the output on, you’ll be able to get a good measurement of the fan. So when
I hit the on button, you can see now the power supply is putting out 12 volts. The fan is
pulling about 350 millivolts or that’s a total of about 4.2 watts. And you can see
here the fan is spinning. So this shows you how the power supply powers the fan and how
you can use the voltmeter and the ammeter to make a very basic measurement on the fan.
The first thing I’d like to observe about this measurement is that the numbers on the
current are moving around a little bit And that’s because although this is a DC fan,
the current isn’t exactly DC current flowing into the fan. Now if you wanted to know what
that current actually looked like, you’d need to look at it on an oscilloscope. But
of course measuring current on an oscilloscope is a little bit difficult. It requires a current
probe or some kind of a transducer and you’d have to have an oscilloscope. But with the
DC Power Analyzer, it’s all integrated into one package.So now to access the oscilloscope
function I push the scope view button and now what you can see is the scope trace of
the fan current. So what we’re looking at here is current versus time on the fan and
you can actually see that it’s not at all DC but it’s actually a current waveform.
Now this is a live waveform, a live measurement. As I take the fan and I slow it down with
my finger, you can see the waveform changes shape. As I slow down the fan rotation, the
period of that waveform changes. So what I can do now with just this one instrument and
one set of connections very simply is power up the device and get an accurate and easy
quick measurement of the power consumption or the power being drawn by this fan.
If I need to make measurements, I mean this is an oscilloscope. I could just count the grid
squares. But there’s also a marker mode. If I hit the scope button again, I can bring
up a set of markers and I can use those markers to make measurements on the waveform.
This was a simple demonstration of how to use the DC Power Analyzer to power up a DC fan and
make some measurements on current versus time using the built-in oscilloscope function.