Ch2

 

Chukwuma Agubokwu
10.22.07

Engineering RP

Chapter Two

Introduction

Traditional sources for electronic energy over the past years have been by outlet by way of transformer by way of a fossil-fuel-based power plant. Recently the feasibility of eliminating all of the steps and the waste and damage caused by them has been brought about by the advent of something that's been around before all of that existed: movement. In technical terms, this is called kinetic energy harvesting*. I aim to conduct research in this area. There are a few methods which have been engineered to conduct such a task including using naturally occurring, electrically charged crystals or ceramics that output electricity when pressure is applied*; electroactive polymers which behave the same way but are significantly lighter*; and electrostatic plates of a charged varactor  in which vibrations are converted into electrical energy*.

I must find a practical and efficient way in which to produce electrical energy by means of regular, everyday movement. To save time on costly and dangerous mistakes in wiring, I will be using a CAD-based* program that will aid in circuit design. The program is called SPICE and I will be using their student edition which is called PSpice* The design on computer will be based in the graphic representation of wiring theory and less the actual physical configuration. Once safely tested  on this design simulator. I can begin creating a live version of my system and begin testing outputs in various degrees to collect extensive information.

 

Accutron Watches

              Accutron Watches are the first ever electric watch to not use the balance wheel and hairspring mechanism that is customary in mechanical watches. They instead used a system that was based around the mechanism of a tuning fork. This tuning fork made the Accutron revolutionary in many ways. The watch's accuracy was significantly better than that of its wheel/spring counterparts because it had only two positions in which gravity could aversely affect the mecanical operations (tongs faced up or down) where as the wheel/spring mechanism was susceptible in five positions (face up or down, winding knob left, right or up). Maintenance and average lifespan were also much improved in this iteration of the electric watch as there were substantially less moving parts than the convoluted wheel/spring system of the time. Something of historic importance about this watch is its use of the transistor, being that it was one of the very first consumer products to use what was a radically new technology at the time. There are other things that made this watch very superior in technological standards to that of the current range of  watches out during its time, but my research focuses on the watch's interface between a physical movement (albeit very minute) and electricity. The way that the Accutron system works is that small bursts of electricity from the battery go into the magnets on either side of the tongs of the pendulum ever so often in order to keep it vibrating. This vibration is in turn harnessed to move the hands on the popularly see through face of the watch. I believe that this system, if slightly reconfigured can work in the opposite direction: the movement of the tuning fork producing electricity.

CAD (PSpice)

          PSpice is the program on which my theoretical circuit testing will be done. This program was created at UC Berkeley to make it easier to run testing on circuit configurations without having to waste time making possibly faulty circuitry. The uses of the program are based on the ability to simulate circuits and their behavior, the version that I use has a GUI that circumvents the requirement of typing inputs in code for each element or connection, I can instead pick visual representations of transistors or diodes and draw wires connecting them. SPICE has become industry standard for circuit design because of the delicate and expensive nature that is undertaken: you just cannot afford to have circuits less than perfect when they cost so much for each tangible iteration. The information that is realized upon analysis of the systems is communicated mathematically with non-linear differential equations, which can be shown in simple but effective graphs along side the workspace.

Pendulum and Human Gait

      The movement side of my research involves  the swinging of a penndulum by way of a human walking. This involves mathematical and physics research in the areas of differentials. I need to combine the formulas used to calculate the forces of a pendulum swinging and a person walking to see how much electricity is generated with each step.

Summary

*Definitions of Terms

1. A charge pump is an electronic circuit that uses capacitors as energy storage elements to create either a higher or lower voltage power source. Charge pump circuits are capable of high efficiencies, sometimes as high as 90-95% while being electrically simple circuits.

2. Varactor is a contraction for "variable capacitor", a type of capacitor  whose energy capacitance (ability to store electricity) can be changed.

3. Piezoelectricity is the ability of some materials (notably crystals and certain ceramics) to generate an electric potential in response to applied mechanical stress.

4. Energy harvesting (also known as Power harvesting or energy scavenging) is the process by which energy is captured and stored. Frequently this term is applied when speaking about small autonomous devices, like those used in sensor networks. A variety of different methods exist for harvesting energy, such as solar power, ocean tides, piezoelectricity, thermoelectricity, and physical motion.

5. CAD stands for computer aided design.

6. PSpice is a SPICE (Simulation Program with Integrated Circuit Emphasis)  analog circuit simulation software that runs on personal computers, hence the first letter "P" in its name. It was developed by MicroSim and used in electronic design automation. MicroSim was bought by OrCAD and now belongs to Cadence Design Systems.

7.Transistor

8.Tuning fork