Download Hydrogen fuel cell

The energy stations are interactive displays to support lab activities throughout the course
of our Energy Academy. Please read below to learn more about the displays and
suggested lab activities.
Hydrogen fuel cell
What type of energy storage is going on here? Where is it?
We can measure the power in 3 different places:
1. the power the light bulb uses.
2. the power the solar panel produces
3. the power the propeller uses.
Guess which of these will be the largest and which will be the smallest. Now measure
them using the kill-a-watt (Watt-hour meter) and multimeters. Remember to put an
Ammeter (current meter) in line with the load (in series), and to put a voltmeter ‘across’
the load (in parallel).
Write down your results in your notebook. Make sure to include a brief explanation of
what you’re doing.
Now make up your own question(s) that might be asked about this station. Are you able
to figure out the answer?
Micro-hydro generator
Un-pinch the tube to let the water run and make sure the generator is turning and the LED
(Light Emmiting Diodes) lights are lighting. (You might have to adjust the hose). Look at
the generator – notice the coils of wire and the spinning magnet – that’s all there is to it!
Measure the voltage of the generator. (Hint – is it AC or DC? Do the blinking lights give
you a clue?) Try changing the height of the water reservoir to see if that changes the
voltage and the speed of the generator. (Refill the reservoir when it starts to get low.)
Now make up your own question(s) that might be asked about this station. Are you able
to figure out the answer?
Hand –Cranked Generator and light bulbs
Connect the generator to one light bulb and turn the crank to light the bulb. (Be gentle
with the generators, they’re delicate.) Notice how hard it is to turn. Now, add more
lightbulbs in parallel and feel how hard it is to light them up. Is it harder or easier with
more bulbs? Measure the voltage and the current in the circuit and calculate your power
you are generating.
Try connecting the bulbs in series and see if the behavior changes.
Try connecting the generator directly to another generator. What do you think will
happen when you turn the crank? Try it.
Now make up your own question(s) that might be asked about this station. Are you able
to figure out the answer?
Coils and magnets
Spin the hanging magnet near the large coil and look at the current meter. Are you
making AC or DC current? Does it matter how close you are to the coil? Does it matter
how fast you spin it? This is the basic principle of an electric generator.
Try moving the coil of wire through the two magnets. Does it matter how close you are to
the magnets or how fast you move it?
Now try the generator flashlights. Notice the magnets and the coils. Do the flashlights
have any way to store energy? (Hint, does the light stay on when you stop generating?)
Look at the taken apart blender motor and notice the coils and the magnets.
Now make up your own question(s) that might be asked about this station. Are you able
to figure out the answer?
Capacitors
Warning – capacitors can be dangerous if charged up to high voltages. Double check with
your teammates that the power supply is set to 5V (this is a safe level).
Charge one of the capacitors with the red and black wires from the power supply and
notice what the current meter does on the power supply as you charge the capacitor (it
happens fast; look carefully!). It will be fully charged in a few seconds. Then use the
capacitor to power the light bulb. Use a timer to measure how long the bulb was on.
Now connect two capacitors in parallel and charge them to 5V. How do you think the
‘double capacitor’ will run the light bulb? Try it.
Now make up your own question(s) that might be asked about this station. Are you able
to figure out the answer? (Ask your TA before experimenting with capacitors, for safety
reasons.)
Energy storage
Calculate the amount of energy stored in a stretched spring. Remember that one way to
calculate Energy is with the equation Work (or energy) = Force * distance. Use the
spring scale to measure the ‘average’ force you use to slowly stretch the spring. Then
measure the distance you stretched it. How many Joules did you store? What do you
think you might be able to do with this amount of energy?
Stand up on a stool. Calculate how much gravitational potential energy you just stored up.
(Use the Newton scale to get the force and a meter stick to get the distance.)
Look at the AA rechargeable battery. It says 2500 mAh, which stands for milli-amp hours.
To get amp-hours, divide this by 1000 to get _______AmpHours. This means that the
battery could put out these many Amps for one hour before it ran out.
If you multiply those Amps by the Volts of the battery, you will get the power it can put
out for an hour.
If the battery can put out that much power (in Watts or J/s) for one hour (or 3600 sec) ,
how many Joules of stored energy does it contain? (Remember E=Rate * time)
How does this compare with the potential energy of you standing on a stool?
Now make up your own question(s) that might be asked about this station. Are you able
to figure out the answer?
Transformer:
This machine is used to change AC voltage to some other value. Use a kill-a-watt
(energy/ power/ Volt/ Amp meter) to measure the Volts, Amps and Watts going into the
transformer. To measure the Amps coming out of the transformer, use the multimeter that
we have previously connected in the power cord. To measure the Volts, just read the
number on the big dial on top –if you have a graded-step transformer- or connect your
multimeter in parallel with the dial set in AC Volts. Start out by transforming the voltage
to a low value. What are the values of the incoming current and the outgoing current?
Measure the power going in and the power coming out.
How many volts does the light bulb need to just start glowing dimly? How many Amps?
How much power is that? How much power does the bulb use when it is bright?
Now make up your own question(s) that might be asked about this situation. Are you able
to figure out the answer?
Mystery Boxes
Try to draw a diagram of how the bulbs are wired together.
Power adaptors
Measure the voltage of the power adaptors. See if they are AC or DC by using a
multimeter, and also the oscilloscope.
If they are DC, which part of the tip is positive and which is negative?
Then take off the tape and see if you are right.
Try lighting 2 bulbs (in series) with the adaptors. Do the bulbs seem to care if they get
alternating current or direct current?
Now make up your own question(s) that might be asked about this situation. Are you able
to figure out the answer?
Light Bulbs
Measure the power used by the different light bulbs. Can you tell which bulbs are more
efficient (that is, they produce less heat compared to light).
Now make up your own question(s) that might be asked about this situation. Are you able
to figure out the answer?