Electricity Generating Keyboard
We are always in need of more energy for our living and hence are trying to make more of it. My aim was to make a self powered wireless keyboard. This type of keyboard could also help provide reusable energy to sustain our lives.
- Make a diode rectifier on the breadboard by inserting the diodes in specific positions. None of the diodes should touch each other, otherwise this could cause a short circuit.
- Insert the piezo element in the breadboard in a specific position.
- Insert the LED on the breadboard in a specific position.
- Test the circuit by tapping on the piezo element. Check that the LED lights up.
- Take a piece of cardboard
- Tape piezo elements in series by attaching red wire to white part and the black wire to golden part of the next piezo (they can be soldered or hot glued)
- Make a diode rectifier by taking four diodes and twisting each of the two sides together. One of the four sides has to have the black parts touching. The opposite point has to have the grey parts touching.
- Attach the two points of the diode rectifier mentioned before to the LED using alligator clips
- Connect the other two sides to the piezo element series using alligator clips
- Test the circuit by tapping on the piezo elements. The LED should light up.
- Replace LED with a capacitor. Charge it up by tapping the piezo several times. The capacitor should store the charge, which is tested with a multimeter.
- Order the circuit board, the soldering iron, the solder and the jumper wires
- Heat up the soldering iron
- Place the four diodes in the same way and solder the ends together
- Solder four jumper wires to each of the corners of the diode rectifier
- Place the correct components in closest corresponding holes
- Connect the piezo elements in series by soldering the proper ends
- Separate a little bit of the top layer of cardboard and insert the piezo elements in the gap (connected in series)
- Turn over the board and solder the LED and the clips to complete the circuit (the positive end of the LED should touch the meeting point of the black side of diodes and the negative side should touch the meeting point of the gray side of diodes)
- Take two alligator clips (four if the capacitor is being used) and connect the corresponding jumper wires to the correct ends of the components
- Test the circuit by tapping the keys on the keyboard and check if the bulb lights up (if a capacitor is used, then the bulb will not always light up because some of the energy is being stored in the capacitor)
- Measure the voltage by using a multimeter
- The breadboard has small connectors which help make proper connections between various components
- The circuit worked and the LED lit up
- We had to understand the circuit before we could do the prototype
- The circuit was connected mainly with alligator wires and it worked
- The amount of voltage for 200 keystrokes is 5.75 volts
- A AA battery holds 1.5 volts
- So, we can charge a AA battery in about 55 keystrokes!
- If an average person does 200 keystrokes per minute, and types for 6 hours, then that person generates 2070 volts each day. This amount of voltage can charge 1380 AA batteries!
- The circuit worked but had a few problems as it was not visible
- We had to take the whole circuit apart repeatedly because the tape was not strong enough
- So, we soldered and hot glued the piezo wires to hold them in place and this worked
- In the final test, 200 taps could generate 2.4 volts, which means that with each tap, the piezo generate 0.012 volts
- If an average person does 200 keystrokes per minute, and types for 6 hours, then that person generates 864 volts. This amount of voltage can charge 576 AA batteries! But, this is not as significant as the other test because the exact places of the piezo elements could not be seen to hit them accurately
- The tests conducted prove that the piezoelectric generator can convert the mechanical stress applied into DC current and can be stored in a capacitor.
- Arranging several piezo elements together in series or parallel increases the voltage produced and helps produce more energy.
- The voltage produced was enough to immediately power a small LED.
- The voltage produced seem to be good enough to power certain rechargeable batteries.
- Therefore, my hypothesis is correct and has been proved by the three tests.
- Hiding a piezo element (such as under the keys of a keyboard) can reduce the electricity generated, as it is not visible, and the amount of mechanical stress is reduced.
(2020, April 11). Retrieved May 15, 2020, from https://en.wikipedia.org/wiki/Thermoelectric_generator
(2020, May 6). Retrieved May 15, 2020, from https://en.wikipedia.org/wiki/Nanogenerator#/media/File:A_summary_on_the_progress_made_in_the_output_power_density_of_triboelectric_nanogenerators_within_12_months..tif
Nanogenerator. (2020, May 6). Retrieved from https://en.wikipedia.org/wiki/Nanogenerator
Capacitor. (2020, May 14). Retrieved from https://en.wikipedia.org/wiki/Capacitor
Building a Piezoelectric Generator - Activity. (2020, March 11). Retrieved from https://www.teachengineering.org/activities/view/uoh_piezo_lesson01_activity1
How Piezoelectricity Works: EAGLE: Blog. (2018, July 13). Retrieved from https://www.autodesk.com/products/eagle/blog/piezoelectricity/
I would like to acknowledge the people who helped me. My mom helped me in making the prototypes, soldering and gave me very helpful advice. My dad helped me buy the materials and gave me some ideas to make my project better. My sister helped me to put jumper wires in my bread board.