3. • 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
What are Microwaves?
4. 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.
5. Parts of Microwave
Control Panel=Allows electric current to flow to transformer.
Transformer and Capacitor=supercharge electricity, and feed
electricity to magnetron
Transformer=changes current and/or voltage into desired
level.
Capacitor=Stores electricity, but in this case soothes
current.
7. Magnetron
Empty tube with magnets around it. The copper wire receives
electric current from transformer and capacitor. Magnets
create magnetic field which make electricity flow out of wire in
beams of electrons.
Each time electrons hit edge of wall, they return back in a
circulation motion. This results in microwaves
Antenna inside magnetron send out microwaves to
waveguide
Basically converts electrical energy to radiation.
9. Parts of Microwave Waveguide=Guides microwaves into cooking chamber. Does
this by confining the space of the releasing microwaves from
the magnetron
Cooking chamber=Chamber that confines the output radiation
so that food can get heated up.
11. How the Oven Works
Electricity from the wall outlet travels through the
power cord and enters the microwave oven through
a series of fuse and safety protection circuits
These circuits include various fuses and thermal
protectors that are designed to deactivate the oven
in the event of an electrical short or if an
overheating condition occurs
• When the oven door is closed, an electrical path is
also established through a series of safety interlock
switches
12. - Sensing that all systems are set to go, the signal activates triac,
producing a voltage path to the high-voltage transformer.
- The high-voltage transformer along with a special diode and
capacitor arrangement increases the typical household voltage from
~115 volts to ~3000 volts .
13. Inside the strong metal box, there is a microwave generator called a
magnetron. When you start cooking, the magnetron takes electricity from the
power outlet and converts it into high-powered, 12cm (4.7 inch) radio waves
The magnetron blasts these waves into the food compartment through a
channel called a wave guide
The food sits on a turntable, spinning slowly round so the microwaves cook it
evenly
How do microwaves cook food?
14. The microwaves bounce back and forth off the reflective metal walls
of the food compartment, just like light bounces off a mirror. When the
microwaves reach the food itself, they don't simply bounce off. Just as
radio waves can pass straight through the walls of your house, so
microwaves penetrate inside the food. As they travel through it, they
make the molecules inside it vibrate more quickly.
15. HARMFUL EFFECTS
Continually eating food processed from a microwave oven causes long
term - permanent - brain damage by "shorting out" electrical impulses in
the brain [de-polarizing or de-magnetizing the brain tissue].
The human body cannot metabolize [break down] the unknown by-
products created in microwaved food
Male and female hormone production is shut down and/or altered by
continually eating microwaved foods.
The effects of microwaved food by-products are residual [long term,
permanent] within the human body.
16. Minerals, vitamins, and nutrients of all microwaved food is reduced or
altered so that the human body gets little or no benefit, or the human
body absorbs altered compounds that cannot be broken down.
The minerals in vegetables are altered into cancerous free radicals when
cooked in microwave ovens.
Microwaved foods cause stomach and intestinal cancerous growths
[tumors]. This may explain the rapidly increased rate of colon cancer in
America.
The prolonged eating of microwaved foods causes cancerous cells to
increase in human blood.
Continual ingestion of microwaved food causes immune system
deficiencies through lymph gland and blood serum alterations
17. Eating microwaved food causes loss of memory, concentration,
emotional instability, and a decrease of intelligence.
Standing In Front of a Microwave Really Dangerous
18. Legitimate Reasons to Avoid Microwaves
There still are some perfectly legitimate reasons to avoid them:
They heat unevenly. This can create unpleasant hot/cold spots in your
food. In the case of baby bottles, it can also cause burns if the outside
of the bottle feels cool, but the inside is boiling hot.
They don’t brown things. Few foods get nice and crisp in the
microwave, because they don’t get hot enough.
They make food dry/mushy/tasteless. This is a matter of personal
preference, and nobody can really argue with it.
19. These are all perfectly fine reasons to avoid microwaves. But none of
them are health problems
If it just makes your life a little easier, there’s absolutely no reason to
avoid them.
