Invention of Microwave Oven

Invention of Microwave OvenMicrowave oven just like many other inventions was invented as an accidental side product of military research. The oven was invented in 1945 by Percy Spencer. He was testing a hyperfrequency wave radiator which he had designed for the air defence radar. He noticed, however, that a peanut bar in his pocket had melted during the test. Spencer was amazed as he hadn't felt any heat himself. To verify his theory he put several corn grains in front of the radiator. He got popcorn right away. However, he failed in his third invention during this day. The egg that he had put under the radiator exploded. Spencer understood that this effect could be used in everyday life. On the 8th of October, 1945 Percy Spencer registered a patent for the apparatus which cooked food with the help of electromagnetic waves. In 2 years when the design was upgraded RaytheonCompany became a world pioneer in the production of microwave ovens. The first oven was 1.8 m high, weighed 140 kg and produced 3000 Watts. That is about 3 times as much radiation as modern microwaves produce. The central part of a microwave is magnetron. It generates electromagnetic waves of 2450 MHz frequency. In 1945 this frequency was allocated to Raytheon Company by the U.S. Federal Communications Commission for the purpose of using it in household appliances. In this way this frequency would not interfere with frequencies used in radiolocation. It also wouldn't trespass domains of TV and FM-radio. It is clear that a big box with transformers, lamps, and wires wasn't able to impress many people. So the first microwave oven wasn't popular. For the two following decades Raytheon Company was gradually reducing microwave size and its manufacturing cost price. The sales especially went up in 1972 when cheap Japanese microwaves had entered the American market. The mid 80s saw booming sales when 90 per cent of American and European families had microwaves in their households. Nowadays more than 200 million microwave ovens are used worldwide for cooking food.

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Science & Technology

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• history of technics
• invention
• microwave
• wave