Three revolutions in the field of human lighting: LED for the third solar street lamp
When the first humans walked the earth millions of years ago, the sun was their only source of energy. The sun gave them light, warmth and, later, food crops. Every night when the sun goes down, the world gets dark.
Since then, humans have been looking for other ways to illuminate the world -- from fires and torches to modern LEDs.
In the development process of human lighting tools, there have been three major revolutions, namely the emergence and application of oil lamp, electric lamp and LED lamp.
In ancient times, in order to defend against wild animals and drive out the darkness, people coated things like pine resin or fat on bark or wood chips, tied together and made torches for lighting. After meeting the basic needs of survival, people hope to apply fire to life, so people will be combustible oil into the container, add the wick lit, became the ancestor of the oil lamp. The use of oil lamps has extended the working and rest time of human beings by 2-3 hours, which is the first revolution in the history of human lighting. Oil lamps have been used for a long time, and they have been improved many times, from animal oil to vegetable oil, and finally kerosene.
The second revolution in human lighting tools came with the advent of electricity. The emergence of electricity made a leap in human productivity, and the subsequent invention of electric light, also created the history of human use of electricity to light. In 1879, Edison lit the first electric lamp with real extensive practical value, and mankind officially entered the era of electric lighting.
In the electrical lighting stage, the development of lighting tools includes a variety of colorful electric lamps. Among them: the electric light bulb is also called incandescent lamp, which is the earliest electric lamp. Only 10% of the input energy of incandescent lamps is converted into visible light energy, and their life spans range from tens of hours to thousands of hours, and they are still widely used today. The halogen lamp is an improvement on the basis of incandescent lamp. Its volume is smaller than incandescent lamp, and the heavier gas with high pressure is filled in it, thus improving the light efficiency and prolonging the service life. A steam lamp is made by passing an electric current through various elements of steam sealed in a glass tube. Steam lamp is a common high pressure sodium vapor lamp, mainly used in road lighting.
The third revolution of human lighting tool is the development of LED lamp. The development of LED began in 1907, when British scientist Henry Joseph Round first observed the electroluminescence phenomenon in a piece of silicon carbide. In 1962, Nick Holonyak of General Electric Company (GE) of the United States invented the LED that can emit red light. George Craford invented the first orange-yellow LED in 1972; The first blue LED light appeared in 1993; In 1999, the first white LED lamp appeared, and finally developed lamps close to natural light in the field of LED research and development, and began to be used for indoor lighting. LED has a series of advantages, such as high efficiency, energy saving, long life, environmental protection and so on. It is known as the light of hope. LED energy-saving and environment-friendly lamps can make people's lives more comfortable, healthy and convenient. It is an indispensable green technology lighting revolution for human beings, and also another huge revolution in the history of human lighting since incandescent lamps.
In addition to emitting energy-efficient, high-performance LEDs, we learned how to control light and developed a range of sensors such as daylight sensors, sensing sensors and camera-based technology.