- Collect all the materials for my design 1 and design 2
- Check whether Thermoelectric Peltier and Piezoelectric Disc work or not
- Decide to build a product of design 1
- Start working on a motor wheel
: Since I had two pretty awesome plans and ideas for this project, I spent a few time to choose which design I a going to make. In the end, I decided to start with design 1 since design 1 with totally my own creative idea, from idea to process. Therefore, the satisfaction of observing my product will be much greater. In addition, I even bought a skateboard for this project, so I wanted to start with design 1. On the other hand, I was surprised by the fact that I can generate energy only by holding the thermoelectric disc and pumping the piezoelectric disc.
- Find a difficulty with the first design: lack of materials and broken material
- Change my mind and start to create design 2
- Built a structure with pipe for the flashlight
: I finally realized that I cannot finish the product of design 1 today. While I was making a wheel, I felt it takes so long time and it is impossible to create four wheels within a limited day. In addition, one of my main material, the piezoelectric disc was not enough. At first, I designed to three four piezoelectric discs at each wheel to stabilize all wheels with symmetry. However, I only found five electric discs, which means I cannot even make two wheels. Moreover, I lost one piezoelectric disc and my motor wheel was broken with unattached electrical wire. Therefore, I sadly decided to change. It felt like I gave up and fail. I really wanted to create my own design from plan to build. It was one of my dreams. More tragically, half of time that I can work was gone and I needed to restart. As a result, I didn’t even have time to regret. Even though enormous pressure was going on on my mind, I needed to start with design 2. Luckily, I could start building design 2 and built a basic structure with a pipe.
- Check how much voltage can piezoelectric disc and thermoelectric Peltier generate. (video at the bottom)
- Find out that it is impossible to turn on the flashlight without the device called voltage booster and the school doesn’t have one.
- Decide the alternative way to use the piezoelectric disc and thermoelectric Peltier to power the flashlight: using the capacitor to store the energy and then turn on the LED when enough energy is stored.
- connect two thermoelectric Peltier
Voltage booster: a DC to DC converter(changes one DC voltage to a different DC voltage) with an output voltage greater than the source voltage. Since I can only generate a maximum 1 voltage with two piezoelectric Disc and thermoelectric Peltier, I needed this converter to increase the output voltage to 3 voltage, which is a minimum requirement for LED.
Reflection: While I kept working on design 2, I encounter another challenge. The total voltage that Thermoelectric Peltier can generate is way lower than the sufficient voltage to turn on the LED. The Maximum total voltage was 0.1 V, and the sufficient voltage was 3 V. Therefore, I researched this problem and realized that I need a device called a voltage booster. Unfortunately, the school doesn’t have one. I came up with an alternative idea, which is storing the energy in a capacitor and turn on the LED when enough voltage is collected. However, I didn’t know how to use a capacitor, and I needed to decide quickly. In the end, I decided to use a rechargeable battery instead of the capacitor. Moreover, by adding a piezoelectric disc on the flashlight, the energy would be generated faster and more efficiently. In fact, the piezoelectric disc could generate enough energy to turn on the LED according to some videos.
Thursday After Class
- Build a piezo button
- Prepare all the materials for the last day, Friday.
- Improve the pipe structure of flashlight for the new design(making a space to attach a battery pack)
- Attach a battery pack
Reflection: I saw a huge improvement and progress. It was the first time I felt that I can finish within a day. Also, it reminded me of a lesson, “effort never betray”. I was building until 6 P.M.
- Attach all the materials like two piezo buttons and two thermoelectric Peltier to the pipe.
- Solder the each piezo button’s positive electrical line(red line) and negative electrical line(black line)
- Connect each thermoelectric Peltier’s electrical
- Decorate the appearance
: I was really glad that my final product looks pretty cool. Through various challenges and solutions, I learned priceless lessons. First, I thought I need to prepare more before I start by checking all the materials are there and consider about the time limit. Second, I needed to manage my materials more carefully. Since I put my materials in a packet without any order, some materials were broken and some were gone. Third, the effort never betrays: if I did not stay until 6 P.M on Thursday, I will not be even close to the finish. Lastly, don’t give up: since I didn’t give up on Monday when I encountered enormous challenges, I can make a second design successfully. However, I couldn’t finish my product 100 percent. I need to solder all the electric wires and build a cover for the LED. Fortunately, it is sure that my final product works if I only solder the wires. The testing video below can explain why my final product will work. Whenever the user pushes the piezo button and holds the thermoelectric handle, it generates sufficient energy. It is because most users will use it outside where the temperature difference between the weather and our hand is huge, which can produce more energy by the Seebeck effect.
Seebeck effect is basically a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances and can generate energy.
Testing 1: Piezoelectric Disc
Testing 2: Thermoelectric Peltier
From Mr. Stenning: recommend me not to cut and solder the wire of thermoelectric generator since if the soldered thermoelectric generator is not working, my project is failed. Alternatively he advises me to twist the wires together.
Mr. Costa: I got really helpful feedback about using machines and tools such as Power Tool and Saw.
Mr. Shokatz: Help me a lot when I have difficulties of cutting the middle pipe.
Mr. Beatty: Teach me how to store all the energy from the piezoelectric disc and thermoelectric generator.
From my friends: they recommend me to stop making the first design and start with a second design quickly. In fact, this advice was really helpful because they let me know the limitation of time and I would not be able to finish the first design.