Physical exercise is must for all human beings to lead a healthy life. Ancient times it came from our day to day activities. In present world urban people are busy with their work and living a mechanized life. The awareness of keeping the body fit is increasing day by day due to the diseases (Diabetes,obesity etc) and mental depression. They prefer fitness devices which is more time valuable and flexible to the user. So demand for fitness devices are increasing and variety of fitness devices are available in the market too. Our idea is to make a novel system from which the energy wasted by human is extracted back as a useful work(electrical power).We virtually modified a basic fitness device (cycling machine) to a system which will efficiently convert our energy wasted during the process into useful high-grade energy.

In a cycling machine the pedal is connected to a disc with adjustable braking set-up by which the torque required to rotate it is controlled and hence the exercising effort. In our system the rotating disc is connected to progressive engaging and disengaging mechanism and then to a gear-box equipped with 4 different speed ratio, designed based on normal cycling speed. An electrical generator with calculated power rating is coupled after gear-box, to match with the optimum speed of generator an additional gear transmission is used to transmit the power from gear-box to generator. Electric power from generator is rectified via bridge rectifier, and is purified by capacitor. Its voltage is controlled and can be stored in rechargeable battery.
Almost all electronic devices (computer, fluorescent lamp, radio, etc) are operating at 12 V DC, which is reduced and rectified from 230 V AC power supply. The above cycling machine is capable of supplying 400W of power, can comfortably power up a home PC (300W), a ceiling fan (60W) and a fluorescent tube (40W).