Energy Transfer: Motors, Generators and Sources of Electricity
y From the Electric Motor kit: electric motor with rotor – the rotating disk of an electric motor or generator . Electromagnets involve a connection between. Find customer reviews of Electric Motor Generator Kit by Dowling Magnets as well as over other toy Even better is the social connection it is making. Motors & Generators Experiment Kit and other robot products. Imparts valuable learning about the flow of electricity; Helps the kids build their Useful Links.
In our example input electrical power of the motor is 0. Motor torque changes with the speed. At no load you have maximum speed and zero torque. Load adds mechanical resistance.
Simple Electric Motors | Award-winning Science Projects
The motor starts to consume more current to overcome this resistance and the speed decreases. If you increase the load at some point motor stops this is called stall. When it occurs the torque is at maximum and it is called stall torque. While it is hard to measure stall torque without special tools you can find this value by plotting speed-torque graph.
You need to take at least two measurements with different loads to find the stall torque. How accurate is the torque calculation? While voltage, current and speed could be accurately measured, efficiency of the motor may not be correct. It depends on the accuracy of your assembly, sensor position, friction, alignment of the motor and generator axles etc.
If you want to get meaningful numbers you might use a second generator kit as explained in Torque and Efficiency Calculation section.Dowling Magnets Electric Motor Generator Kit package contents
Speed, torque, power and efficiency of the motors are not constant values. Usually the manufacturer provides the following data in a table like this one sample data from one of the motors used in generator kit: Also the manufacturers usually provide power curves for the motor at nominal voltage: Look at the science project Put Your Water to Work: Using Hydropower to Lift a Load to get ideas on how to build a water wheel.
Figure 22 can give you ideas on how to create a windmill. Remember to glue the magnets onto your hex nut if you want to try fast rotations, in order to prevent magnets from flying off and causing a hazardous situation.
Powering a generator with a windmill. You can extend your testing by adding a third coil to the generator. You could choose to make a third coil with two layers.
Find out how different combinations of these three coils allow you to test configurations from 2 layers up to 12 layers with increments of 2 layers of wiring. When combining coils, make sure that coils are synchronized or have their induced current flowing in the same direction and their peak induction at the same time. Explore the effect that changing the configuration of the magnets has on the induced electricity. Manipulating Magnets to Improve Generator Output will help you get started.
If you do have a multimeter to measure the AC current or voltage, you can study the influence of the speed at which the shaft turns on the generated electricity. Note that you might need to change the rotational speed quite a bit to be able to see a difference in the number of LEDs it can power.
This should not be an obstacle if you have a multimeter that allows measuring of alternating current or voltage available. Remember to glue the magnets onto your hex nut if you want to try fast rotations, so the magnets will not fly off and cause a hazardous situation. If you have an oscilloscope to visualize the change of current and voltage over time, calculate the power of the generator with coil 1 only, coil 2 only, coil 1 and coil 2 connected start to end, and coil 1 and coil 2 connected end to end.
Share your story with Science Buddies! Yes, I Did This Project! Please log in or create a free account to let us know how things went. You may find the answer to your question. This guide contains answers to some frequently asked questions for both projects from the generator project idea series: The axle of my coil winder seems flimsy, almost falling apart. The connections between the unfolded paperclip and the bendable iron core are probably not sturdy enough.
Undo the current connections and follow the instructions below. Make sure to use masking tape. Other tape might result in a weaker axle. To connect the unfolded paperclip to the iron core: Lay the masking tape flat on a surface. Affix the paperclip to the core by folding the short end of the tape over the core and paperclip.
Now wrap the long end of the tape around the connection. Twist the tape a little on the side where the paperclip sticks out to make the connection even stronger. Creating a sturdy connection between the unfolded paperclip and the bendable iron core. Use the following procedure in case you find it difficult to create a sturdy connection while the axle is partially in the coil winder: Attach both unfolded paperclips to the bendable iron core before placing it into the coil winder.
Unfold one L-shaped paperclip completely so it becomes a straight line.
Using the straight side of your axle, poke the axle iron core with both unfolded paperclips attached through the holes of your coil winder starting from the V-shaped corrugated cardboard, then the box, followed by the hole in the other side of the box, and finally, the hole in the last V-shaped corrugated cardboard. Bend the straightened paperclip back into an L shape.
The axle of my coil winder seems to go up and down while I wind the coil. See if the axle supports the corrugated cardboard strips that are folded in a V shape with flaps and attached to the side of your coil winder do not move while you are winding.
If they do, use more or better tape to attach them better and try again. Masking tape or packaging tape will work well here. If your axle is still going up and down while turning, the long side of one or both of the unfolded paperclips is probably not straight.
Try to straighten it as much as you can. You might need to take the axle out of your winder to do this. Sometimes, it is easier to start with a new paperclip, unfold it, straighten it, and attach it to the core. When winding the coils, the windings become increasingly less even as I add more layers. It is normal that windings become increasingly less neatly arranged, one next to the other, as more layers are added, as any irregularity in one layer makes it harder to evenly wind the next layer.
To get a good result with as few irregularities as possible, it is very important to wind the loops very neatly, one next to the other, when creating the first layer of loops on the bendable core. Use your thumb and pointer finger to pack individual loops tightly together in case they tend to spread out.
Do the best you can for all of the following layers. Figure 2 shows some acceptable results for consecutive layers of winding. Consecutive layers of winding might show increased irregularity.
Shed Light on Electric Generators: Do More Coils Generate More Electricity?
Bending the bendable iron core seems so hard. You do need to put some force on the core to make it bend. Figure 3 shows the process. Here some tricks that might help you create a bigger force: Use the palms of your hands, close to your wrist, to hold the core on the table and push the free end over. Use mittens or cloth to protect your hands. It might allow you to push harder without hurting yourself.
Use leverage by putting your second hand near the end of the iron core, as far as possible away from the table edge. Bend slightly over the core and use your body weight to create a bigger force. Once the coil is in somewhat of a U shape, you can fold the coil a little more by pushing the legs toward each other.
If all of the above fail, you might need to ask an adult for help. Illustrations of the different steps involved in bending the coil. I stacked the neodymium magnets and now I am having difficulty separating them. Neodymium magnets are strong, be patient when separating them.
They can usually be separated by hand, one at a time, by sliding the end magnet off the stack. If you cannot separate them this way, try using the edge of a table or a countertop. Place the magnets on a tabletop with one of the magnets hanging over the edge.
Then, using your body weight, hold the stack of magnets on the table and push down with the palm of your hand on the magnet hanging over the edge. With a little work and practice, you should be able to slide the magnets apart. Just be careful that they do not snap back together, pinching you, once you have separated them.
Next time you stack the magnets, you might want to cut out small pieces of cardboard and place them between the magnets. The cardboard will help them separate more easily.
I have a hard time keeping track of the polarity magnetic north and south poles of the neodymium magnets. A compass like the one that comes in the science kit can always be used to verify the polarity of a magnet. Bring the compass in the vicinity of your magnet. The white part of the needle will point to the magnetic south pole and the red part of the needle will point to the magnetic north pole, as shown in figure 4. Once you identified the pole, you can color code them by placing small pieces of masking tape on the magnetic north pole side of the magnets.
A compass placed in the vicinity of a magnet indicates the magnetic poles of a magnet. My magnets tend to fly off when the generator is turning fast, what can I do? Definitely use a strong glue e. Magnets flying off are a hazard. If you would like to try different magnet configurations, we advise you choose from the following options: Test at a slower rate of rotation, where there is no need to glue the magnets on the hex nut.
In this case, the magnet configuration can be changed by switching magnets around. Glue the different magnet configurations on two different hex nuts, creating two rotors. Switch rotors to test the different magnet configuration at a high rate of rotation.
Note that although a rotor with six neodymium magnets is advised in the science projects, you can get good results with a one coil generator and two neodymium magnets placed degrees apart. My LED does not light up when testing a generator created with one coil containing six layers of windings and a magnetic configuration with alternating magnetic poles facing out. First, make sure to dim the light in the room when testing. Give a quick short turn to the rotor. Some students need to implement a mechanism that creates fast enough bursts of rotation to generate light.
Consider trying the "bucket with waits" mechanism described in the procedure to create fast turns. Here some things you can check: Do both leads coming from the coil show a bare wire section, or a section where insulation has been removed?
You should be able to see the bare wire all the way around. If not, remove remaining insulation and try again. Hints on how to remove insulation efficiently can be found in the procedure of the science project or in the Science Buddies Wire Stripping Tutorial.
If you have a multimeter any typethis step explains how to use it to narrow down which part of your generator is failing. If you do not have a multimeter, go to step 3, below. Although measurements of a DC multimeter will not be accurate due to the alternating aspect of the generated current and voltage, it can still be used to indicate whether current or voltage is present during a quick turn of the rotor. If voltage over or current through the coil is detected when making a quick turn, the circuit to the LED was somehow broken.
Step 3, below, will help you further narrow down the problem. If the multimeter does not detect any current or voltage, skip step 3 and check the magnet configuration step 4, below and the wiring of the coil step 5, below. Is there a closed circuit of conducting material connecting the coil and the LEDs? Does the bare wire section of a coil lead touch the nail, and only the nail? You might want to wind the bare copper section of the lead a couple of times around the nail. Check this for both the start and the end lead.
Does each nail touch one, and just one, leg of the LED? Is your LED working? Check with a new light if you have one available.