The Theory
What is piezoelctricity ? Piezoelectric Effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress or in more detail piezoelectricity, also called the piezoelectric effect, is the ability of certain materials to generate an AC (alternating current) voltage when subjected to mechanical stress or vibration, or to vibrate when subjected to an AC voltage, or both. In our case we only use ability of certain materials to generate an AC voltage.
Application Design
There are a number of applications of piezoelectricty and various methods of harvesting piezoelectricity. But we were cautious not to repeat any of conventional harvesting methods. When we looked around we saw various of methods but of we found this most efficient. We are assembling piezoelectric elements on the wheel of a vehicle. When the vehicle moves one of piezoelectric elements come in contact with ground on which a pressure is exerted . And due to the pressure variation it generates an alternating voltage. Next instant another piezoelectric element come in contact with ground and it also generates a similar alternating voltage. When vehicle moves fast all of piezoelectric elements come in contact with ground and all of them generate alternating voltage,then it is conducted through the RIm of tyre and passed through the bridge rectifier circuit to converting the AC component to DC .This power is utilized for the charging the battery in vehicles. By this energy harvesting we are making a attractive map guide for the cyclist with a Esp-01 micro controller.
The power will mainly depends mainly on two factors
1.The surface area of the tyre.
2.The rpm of tyre(rotations per minute)
so we should take care of that.
I hope that,it is a reliable and continuous source of energy for the moving vehicle is guaranteed.