10-01-2012, 12:28 PM
How a Microwave Oven Works
MicrowaveOven.ppt (Size: 858.5 KB / Downloads: 240)
What are Microwaves
Microwaves are a form of electromagnetic energy, like light waves or radio waves
Microwaves are used extensively in communications
such as to relay long-distance telephone signals, television programs and computer information across the earth or to a satellite in space.
Good for transmitting information because it can penetrate haze, light rain and snow, clouds, and smoke.
Also used in radars and in detecting speeding cars.
Microwave has become most familiar as the energy source for cooking food.
Electromagnetic Spectrum
Electromagnetic radiation exists in a range of frequencies called the electromagnetic spectrum.
Each frequency has a specific wavelength and as the frequency decreases, the actual length of the wave gets longer.
History
Invented accidentally by Dr. Percy LeBaron Spencer
While testing a magnetron during work, he discovered the candy bar in his pocket melted
Experimented with other food products (popcorn and eggs), and realized microwaves can cook foods quickly
At 1947, 1st commercial microwave oven produced (called Radarange)
Mostly used by restaurants, railroad cars, ocean liners and military
Improvement and refinements made ~ by 1967, 1st domestic microwave oven produced