Fresnel Lens

Fresnel Lens is a type of lens that can serve as a light concentrator and energy source. Because of the large amount of heat generated by a fresnel lens, great caution is needed in its use. Augustin Jean Fresnel invented the lens in the early 1800s. Fresnel lens have been used in reflectors for lighthouse lamps, illumination for overhead projectors, large-format view cameras, TV projection, and 3 dimensional photography.

Because the tropics is greatly endowed with sunlight, the fresnel lens can prove to be a powerful source of energy, powerful enough to melt metal and concrete.


Design


Fresnel lens are smooth and flat on one side and ridged and stratified into circular segments on the other. The rough and ridged surface are the surface of a magnifying glass cut into segments. The fresnel lens was invented to create a lens that was not to bulky and heavy. Being bulky and heavy , would cause the lens to absorb light. Its inventor discovered the curvature of the lens caused light to concentrate and form a beam. The thickness of the lens did not serve the latter purpose.  Augustin Jean Fresnel cut the curvature of a lens and laid it on a flat surface, greatly reducing the bulk. 

Obtaining


Large screen projection television contain large fresnel lens. Fresnel lens can be taken from a large screen projection television--50", 60", 70".  These televisions have two type of lens, Spot Lens and Linear Lens. Both lens can be used for cooking. The Spot Lens are more powerful and can melt metal and concrete. The Lens should be taken out of the television and placed in an adjustible wooden frame. The sectional and ridged edge surface of the lens is placed towards the sun.

YouTube Video


tags: energy cooking science