Tuesday, December 29, 2020

How microwave oven works

Microwave oven popularly known as a microwave was invented by an American scientist Percy Spencer in 1958 by accident.

The use for microwaves as the preferred mode of cooking/warming food in seconds has become a preferred mode of cooking food by most families.

So how does the microwave work? First let me say that microwaves, unlike other cooking methods like gas and electric coils cook food using frequency.

A little about frequency

Frequency is measured in a unit called hertz.

Hertz(Hz) is equal to one occurrence of repeating events per seconds.(Frequency=1/time), time in seconds.

Microwave use a specific frequency of 2450 megahertz(2450x1000,000 Hz)

So we can conclude that microwave frequency cycles 2.45 x 10^9) times per seconds.

Water molecules within the food are bombarded by the microwaves and the resulting vibrations(friction) generate heat and cook the food.

Microwaves pass through plastic, glass and ceramic but not metals, that is why it is not recommended to use metal container utensils in a microwave oven.

The component responsible in generating these microwave is the magnetron

Simply put a magnetron is two permanent magnet on either side of a vacuum tube.

Note: Microwave cooks(heat) food from inside out- that is why you cannot cook an egg in the microwave because the yolk will cook faster than the outside causing the egg to burst.

You can learn more about microwaves and how to repair them here.

Click the book cover to learn how you can put back a smile on your microwave.


  1. Hi Humphrey,
    In Microwave Oven Repair on page 17 in my printed copy first paragraph it mentions high voltage AC changed to DC and doubled using a voltage doubling circuit. A doubled voltage of AC goes to magnetron and any DC would be between diode and ground, right?
    I think you did well on keeping things understandable and I am re-reading the book. Lawrence Mc Coig

    1. Thanks for the feedback and all the best Lawrence.

      Regards Humphrey