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Step 7: The magnetron

Picture of The magnetron
P3080024.JPG
This device, the magnetron, is what heats up our foods...

There is hardly any use for this device, but the magnetron have two very large and powerful ceramic magnets! You can hack the magnetron open and extract the magnets and use them for your other projects.
 
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Please read the quote as follows.

[Quote begins]

http://www.geappliances.com/search/fast/infobase/10001153.htm

Microwave - Normal Operational Characteristics for a
Microwave

It is normal to experience any of the following with a
microwave oven:

[...]

Dull thumping
sound or hum while cooking at power levels other than high.

When using a power
level other than HIGH or 10 the magnetron tube cycles on and off to obtain the
lower power. This cycling of the magnetron tube causes this dull thumping, pulsating,
or humming noise. When combination cooking in microwave/convection models, the
cycling of the convection element and fan will alternate continuously with the
hum of the magnetron and the fan.

[...]

[Quote ends]

What do you mean by power cycle, high and low, so that low
power cycles can cause noise while high power cycles will not.

What I know is that high power or low power cycles depend
upon how long in time period the magnetron is working and how long in time
period it stops working until the next period of work to be interrupted again
by the period of non-work; and the joined period of work and of non-work is set
by the human operator using the power knob or button.

My problem is the following:

Power is set at maximum – no interruption of work for magnetron: for the first 2 minutes
more or less of magnetron operation it emits a jackhammer noise which stops at
the end of the 2 minutes period, and the magnetron continues to operate
'quietly' until it stops at the completion of the adjusted operation period or
I turn it off.

This microwave oven is not digital but mechanical in its
control, it had been in service for over 7 years. It started blowing up the
power fuse, and upon changing the power capacitor the normal function was
restored and it works as before except for the noise which was not present
before.

Please suggest some solutions; I notice that it seems the
magnetron now needs to get heated up before the noise will go away.

Please ask your engineers to investigate the mechanics and physics
of heat and noise and vibration in the operation of perhaps an overly aged
magnetron.

Thanks in advance for your reply by email.

My email: mdejess@gmail.com

jupeter54 years ago
ummm... you can use the magnetron to build a micro wave gun. basically it can also be used as an EMP device so it does have a use.
Do you think you can show me how? I want to make a Sonic Screwdriver with one of those inside it.
snateraar3 years ago
Mind you, some parts of the casing of the magnetron itself like the pink-ish ring around the outlet may contain berrylium oxide which is not quite healthy.
It's safe as long as you don't inhale it though.
Yeah, as long as you don't scrap off the beryllium oxide and snort it, you should be okay.
knoxarama5 years ago
hardly any use? you can make radio transmitters with these strong enough to kill anything that walks in front of it, mostly birds. some scientist guys in the hemelayas stood in front of giant magnetrons to heat themselves up. that can't be healthy...
And I bet that they all died of cancer or had random mutations by now.
Aleksa324 years ago
plasmana how to fireup the filament? how many amp's does the transformer need? i tried with a small 6v miniature transformer and it was like a short circuit,i think that something is wrong...
In my opinion, it would be sheer stupidity to fire up an unshielded magnetron. Not only would it cause cancer, but if left on for a few seconds, and your body would look like a tv dinner that was just cooked. If you want to fire one up, use sheet metal(steel) as shielding, and be warned that electronics would be fryed and probably your hand to if you stuck it in the why of the microwave beam.
ne171pro5 years ago
Magnetron Hardly Any Use? I'm not trying be rude but your PDF here showed me how to take apart my microwave so I could get the magnetron. (not for its magnets) Anybody out here that can help wire up my magnetron. I'm really not stupid with electricity, I cant for the life of me get it to do what I'm seeing freaking 14 year olds do. I know its not broken components (have 3 taken apart microwaves.) Is it the ground wire you touch it with? Or is just some other wire not in the circuit. Man I'm so frustrated.
omnibot6 years ago
I don't believe those magnets in the magnetron are neodymium. All I've taken out, although very powerful permanentmagnets, are far from neodymiums.
Plasmana (author)  omnibot6 years ago
Yeah, neodymium magnets very often have a nickel coating to protect it from corrosion, they look a lot like ceramic magnets, but everybody else says they are neodymium magnets...