A Gravity Driven Sun Tracking System for Solar Cookers

Abstract

A relatively simple gravity operated device for sun tracking especially suited for use with solar cookers has been described in this invention. The device utilizes two wooden boards connected to each other through bearings. Board on the top is rotatable with respect to the bottom one. Solar cooker is placed over the board on top. A spring is constrained to expand inside a semicircular curved pipe having a slit at the top. The curved pipe is horizontally fixed to the board at the bottom. One side of the spring is held fixed, while the other side attached to a cord and a vertical rod is allowed to move. The attached cord goes over a pulley after which a liquid filled container is hanged. The liquid filled container has enough weight to impart the spring a maximum stretch in the beginning The liquid is discharged from the container at a constant rate allowing the spring to contract at a constant speed, taking along the board on the top through the vertical rod. The system provides faithful tracking of the solar cooker for up to six hours, without using any external source of energy.