Measure. Analyze. Learn.
We're going to use the new Vernier High Current and
higher voltage sensor today.
And, we created this specifically for this environment.
For maybe testing solar panels, or doing some
alternative energy, things like that, with a small windmill.
And so, I'm going to use these two together.
And, what I have is a photovoltaic panel here.
And then, I'm going to run a motor.
This is just an old electric fan from a car, so it's a 12 volt motor.
And, I can drive the motor with the photovoltaic panel.
And, I can measure the current, and I can measure the voltage
simultaneously, and then calculate the power produced by this.
And so, this is the kind of thing you would
end up doing with this sensor.
The High Current Sensor, it is a hall probe
for measuring current; up to 10 amps of current.
You don't want to go above that, you could damage the sensor;
at a maximum of 40 volts.
And so, for that one, you want to keep it in those ranges.
And again, for something like this, for the photovoltaic panel,
it’s kind of perfect for that one.
And then, this is the 30-Volt Voltage Probe.
And, this panel produces about 18 volts open circuit,
so, it should be fine for this.
So, what I've done, is I have this wired up so that I have
the current sensor wired in series with the motor.
And, when I attach the wire, it's going to allow the current to flow.
We can measure the amount of current.
And simultaneously,
I've attached the voltage probe across the load.
In this case, it would be the motor.
And, as the motor starts to turn we can measure the power.
I'm going to plug in my sensors.
And so, they are both analog,
so, I'll plug a current sensor into channel 1,
my voltage probe into channel 2.
And, I'm getting readings close to 0.
I don't have my circuit connected right now,
so that should be fine.
And, one of the things about doing work with this outdoors
is that the LabQuest has a new high contract screen
that makes it easier for us to see what we are doing outdoors.
And so, I'm going to actually change this.
And so, if I go under the [house icon] there. Click there.
I can go to the 'Preferences', and then under 'Light & Power',
I click there. And then, down in the lower left hand corner
I have 'High Contrast'. So, if I check the box for high contrast.
Then, I can close that out. And you will see, that it will actually
change to a black and white.
It makes it much easier to see when you are out in full sun.
So, at this point, I'm going to be ready to collect my data.
And before we do that though,
let's take a look at what we're going to be collecting.
It says up there it's 'Mode' - 'Time Based'.
We're going to look at current and potential as a function of time.
10 samples per second, that’s fine for what we’re going to do.
And, 15 seconds. And so, that will be fine.
So, what I will do is, I'm going to start collection first,
then I will connect the circuit. So, I'm going to attach
the wire to the current sensor to complete the circuit.
And, we'll measure the current and potential together.
And then, we'll come back and do a calculated column of power.
So, at this point, I need to hit [collect]; here we go;
and, I'm going to attach my wire;
and as soon as I do that…
Ahh, there we go.
So now, we have some data.
And, at this point we could take a look at it.
And, at first, we see while I was attaching the wire here,
I kind of attached it and unattached it,
so we had a little bit of a little bobble there.
And here, we see that the current jumps up here.
The voltage actually begins to increase a little bit
as the motor begins to spin up, we end up with
a little bit of back e.m.f., and at some point it kind of
reaches a maximum up here.
Takes a few seconds for it to be able to get up to full power there
Now, at this point, what I might want to do is
actually look at my power produced by my panel.
And so, to so this, I need to do a calculated column.
And, when I do the calculated column,
I need to do that from the data table.
So, I'll go up, and open up my data table.
And then, under 'Table', I can do 'New Calculated Column'.
So, I'll go there. And, what I want to do is
multiply the current times the voltage.
That ends up giving me power, with the unit of watts.
And so, at this point, I'll come in; I'll rename that;
and so, I'll rename this 'power'; and 'Done';
and my units as 'watts'; {and watts}; 'Done';
So, I have my name and my units there.
Now I need to do my equation.
So, my equation that I want, I want to be able to multiply
the current times the voltage.
So, I need to go down here, and find where it says 'XY'.
So, I'll just slide down here, and so, there we go with 'XY'.
So, I'll select 'XY'.
And then, it comes up here and says, well what's X.
And it's defaulting for it to be time, and the Y to be current.
Well, I don't want it to time. I want that to be potential or voltage.
And so, I'll come here, and tell it to be 'Potential'.
So now, I will, when I hit 'OK',
it will multiply potential times current,
and will give me a graph there with the watts.
Now, here's what I want to do here.
I want to show just one of the graphs,
and I want to make the graph be the power, here.
And so, I'm going to go to 'Graph'; and I will do 'Show Graph'; 1
And, right now it's doing power in terms of watts,
in terms of time.
And so we see at first, there's my little bobble
when I'm connecting the wires,
and the power production begins to increase,
and it peaks up here someplace.
So, I might want to actually do some analysis.
I could just come over here, and may be examine.
And, if I do that, it tells me what's the power production there;
9 watts up there; so, I'm getting about 10.
I could, at this point, come in and, actually do, under 'Analyze',
go and run my 'Statistics'.
But, maybe if I want to find out,
"What was the maximum power production?"
And so, I end up with about 12 watts, there, when it does that.
So again, the High Current and 30-Volt Voltage Probe
is an excellent probe if you want to study alternative energy
with photovoltaic panels, or windmills.
And so, it is definitely a good option
for doing those kind of experiments.