We believe that the faster a dynamo rotates the more electricity it will create. if you dont spin it fast enough the light will not turn on. We think that when you spin the crank faster the lightbulb will get brighter.

Background information

Who created the first Dynamo?

The inventor of the dynamo is a man named Michael Faraday. He invented the concept of it in 1831. He used a disc rotating between the poles of a magnet to create a current that he got from brushes contacting the disc. From this he created Faraday's Law, which describes how a change in the magnetic field around a conductor induces a voltage (electromotive force, or EMF) in it. This induced EMF is directly proportional to the rate of change of magnetic flux through the coil and the number of turns in the coil. A German electrical engineer Werner Siemens named the dynamo in a period around 1816-1892 named after the Greek word “dynamis” meaning power.

How a Dynamo Works

A dynamo converts mechanical energy into electrical energy. It does this by rotating wires in a magnetic field. The magnetic field exists around the magnets used in the dynamo. When the coils of wire spin inside the magnetic field it creates a charge in the wires. A commutator is used to ensure that as the coil's sides swap positions (from positive to negative), so they maintain the same polarity to the output, resulting in a consistent direct current. The produced DC electricity can power devices like lights.

Independent Variable: The speed we spin the crank on the dynamo

Dependent Variable: How bright the light shines

Controls: the dynamo, the lightbulb, the timer, the person spinning the crank

1. Build a dynamo a. punch out the base b. punch out the wheel bases c. use the screwdriver on the screws and the holes except on the one in the middle of the three opposite the other seperated 2 d. attach axles into both holes, facing opposite ways, and the one not in the center gets a handle attached to it e. attach the other three small wheels onto the other axle, then set up the axle setup on the base f. set up the wires by twisting and pulling on the small cut insulation g. punch out 2 small squares with holes in them and find their correct place on the base, then set one up only h. grab the motor in the kit bag and put it into the small holes in the squares facing inwards of the base i. attach the ports onto the motor and grab a pulley wheel and attach it to the axle of the motor, and secure it in place using the parts included j. set up the stands for the light and attach the lightholder and run both wires through k. attach the ports of the motor via the wires to the usb board converter l. connect the usb port to the light m. use the rubber band and connect the big wheel to the motor wheel, making a tread n. make sure its all secure

2. Spin the crank at the following 3 different speeds: 1 turn/ rotation per second\, 1/2 rotations per second\, and 2 rotations per second\, and observe the lightbulb

3. Record our observations and compare

Our observations were recorded and shown as a table.

We observe that in all 3 tests when the dynamo wheel isn't spinning fast enough, it doesn't generate enough electricity to power the LED. Also, that the big wheel needs at least 2 cranks per second to power the LED light.

lOur analysis is that in all 3 tests when the dynamo wheel isn't spinning fast enough, it doesn't generate enough electricity to power the LED. Also, that the big wheel needs at least 2 cranks per second to power the LED light.

You when you spin the wheel, at 1 per per second no light comes on and at 2 cranks per second or faster consistent power is sent to the light and it stays on. So, our hypothesis was correct the faster we cranked the dynamo the brighter the light shined.

Dynamos are currently being used in;

• bikes, for generating power to bike lights
• small special use hand crank devices
• small scale reusable energy where hydro or wind power can be used to generate DC power

Our experiment showed that the faster we cranked the lighter the bulb, which means more power was being generated. To apply this knowledge to a small scale reusable energy dynamo system you would want to place the hydro systems in a fast moving stream or your wind turbine in an areas with high speed winds to get the most energy out of the dynamo.

Dynamos are not used much in todays world as generators are much more efficient as they do not required a split commutator to change the energy to DC from AC.

The fact that we spin the wheel ourselves means that their could be error with our timing of rotation. The dynamo itself is fragile and could be damaged from using it.

https://ui.adsabs.harvard.edu/abs/2013AmJPh..81..907S/abstract

https://www.diy.org/article/dynamo

https://www.etymonline.com/word/dynamo

https://www.khanacademy.org/science/shs-physical-science/x0492729e402f0c6b:4th-quarter/x0492729e402f0c6b:light-as-a-wave-and-a-particle/a/what-is-faradays-law

Pictures:  https://americanhistory.si.edu/collections/object/nmah_709848

https://www.techagekids.com/2016/09/michael-faraday-resources-for-kids.html

https://www.explainthatstuff.com/generators.html

https://www.diy.org/article/dynamo

https://en.wikipedia.org/wiki/Faraday%27s_law_of_induction

We would like to Thank our Mom's Carolina and Karen for helping us be organized and for supporting our ideas. We would like to thank Ms.Acurri and St. Joseph school for putting on a science fair. Finally, we would like to thank the people at CYSF.