Microwaves

[martin perman 1Participant @martinperman1]

Gentlemen,

This question is purely for curiosity but are there any useful parts inside a Microwave, these pop up on Freecycle regularly in "working order" my first thoughts are pieces of stainless sheet but what use are the guts.

Martin P

[martin perman 1Participant @martinperman1]

[Les Jones 1Participant @lesjones1]

Hi Martin,
Probably the most usefull part is the transformer. As they are they are they are not much use with the high voltage (Over 1000 volt.) secondry winding but this can be removed an a new low voltage secondry winding added. I have seen people using them to make a spot welder with just a few turns of copper bar ( Or very thick cable such as welding cable.) as a secondry winding. There a a few (Only made by Panasonic as far as I know.) that do not have a normal mains transformer. These are much lighter in weight. They use an inverter instead of the transformer. IF YOU DO TAKE ONE APPART SHORT OUT ANY CAPACITORS AS THESE CAN HOLD A HIGH VOLTAGE CHARGE.

Les.

[Geoff TheasbyParticipant @geofftheasby]

A little, the turntable motor, a few microswitches, the mains plug. But BEWARE of the high voltage capacitor near the magnetron, a two terminal device which can kill you with an electric shock if not discharged first by shorting with a heavily insulated screwdriver.

Geoff

[Brian WoodParticipant @brianwood45127]

The magnets around the magnetron are very powerful and make good swarf collectors when fitted inside plastic pots, better still if you include a lifting shaft in plastic to pull it past an outer collar that shovels off the swarf. They are light enough to position strategically to catch cast iron swarf as it is generated which otherwise finds it's way into everything.and everywhere.

Regards

Brian

[DMBParticipant @dmb]

Martin,
I understand that whole design has changed, eliminating the large + very heavy transformer. Quite how I dont know as I’m not an electronics whizz.
FWIW, I once read about how to alter it to make a spot welder. IIRC, it was by replacing the secondary winding with just a single winding of welding lead with the ends run out to one fixed terminal and one moving terminal.
I believe that it could have been written in detail on madmodder.
Regards,
John.

[Ian S CParticipant @iansc]

I,v got a half made spot welder made from a MW transformer, also a demagnetiser made from one of the coils from a MW transformer. I use the magnetron magnets in a linear alternator on a free piston Stirling Engine. The case is a good source of sheet metal. The primary, and secondary coils, either will do, run them from a reasonable size transformer at about 12 volts, the demagnetiser is the wooden box with the rectangular hole. Ian S C

Edited By Ian S C on 29/03/2015 10:35:13

[martin perman 1Participant @martinperman1]

Gentlemen,

Thanks for the information I like your idea's, as some of you know I restore stationary engines and maybe I could build a magnetiser for re magnetising my magneto magnets, the other bits are always useful.

Martin P

[Malcolm BannisterParticipant @malcolmbannister38996]

Posted by Brian Wood on 29/03/2015 10:16:52:

The magnets around the magnetron are very powerful and make good swarf collectors when fitted inside plastic pots, better still if you include a lifting shaft in plastic to pull it past an outer collar that shovels off the swarf. They are light enough to position strategically to catch cast iron swarf as it is generated which otherwise finds it's way into everything.and everywhere.

Regards

Brian

Hi all.

If you're dismantling magnetrons, be very careful not to chip or raise any dust from the insulation. It contains beryllium oxide which is nasty stuff.

HAZARD SUMMARY

* Beryllium Oxide can affect you when breathed in. * Beryllium Oxide is a CARCINOGEN–HANDLE WITH EXTREME CAUTION. * Contact can cause eye irritation, redness, itching and burning. * Beryllium Oxide can irritate and burn the skin. Higher exposure may cause skin ulcers to develop. * Breathing Beryllium Oxide can irritate the nose, throat and lungs. * High exposure can cause bronchitis and/or pneumonia with fever, cough and shortness of breath. * High or repeated exposure can cause permanent scars in the lungs with fatigue, weight loss, poor appetite and shortness of breath. Lung damage and heart failure can occur years later.

IDENTIFICATION Beryllium Oxide is a white, odorless powder. It is used in the manufacture of ceramics, glass, electron tubes, electronic components, nuclear fuels and nuclear moderators.

Just so that you're aware.

Malc

 

Edited By JasonB on 09/04/2015 16:55:42

[jason udallParticipant @jasonudall57142]

Gee. and they let people have those things in the home.

[DMBParticipant @dmb]

Malcolm,

Is that the same powder that comes from broken fluorescent light tubes? Maybe thats why the Council refuse collectors dont want to know?

John

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by jason udall on 09/04/2015 23:33:58:

Gee. and they let people have those things in the home.

Hi Jason, they also let you have stuff like gas and electricity which can injure and kill you much faster if you foolhardy to muck about with them.

Regards Nick.

[Malcolm BannisterParticipant @malcolmbannister38996]

Hi John..

That's the stuff.

Cheers

Malcolm

[Danny M2ZParticipant @dannym2z]

Microwaves also have the property of disrupting your local home WiFi system (when they are working).

I tried this with a laptop. It's true – the signal bars dropped out when I was making a cuppa.

**LINK**

* Danny M *

[Jesse Hancock 1Participant @jessehancock1]

Never liked WiFi and have always wondered why people have it in their home. (Fine if you're out and about.) Used to get terrible reception whenever a motor vehicle went by. (not so bad today(better insulated)).

As for other stuff which affects your lungs almost everything you breath with the exception of clean air does you no good. (See discussions on fumes from lathes etc.) Coal miners, steel makers, flour millers, loft insulators, and on and on. Any industry generating seen and unseen air pollution is no good to human longevity. Remember the Swedes moaning about acid rain coming from Britain? Drive motorways for long enough and you will be filthy and possibly feeling tired or ill from fumes (hence the recommendation to take frequent rests).

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Danny M2Z on 10/04/2015 06:30:25:

Microwaves also have the property of disrupting your local home WiFi system …

.

Have a look at the MetaGeek website.

MichaelG.

[Neil WyattModerator @neilwyatt]

I have a great article on making a spot welder from a microwave, with detailed design and drawings lined up for a few month's time.

Neil

[KWILParticipant @kwil]

Spot welders made this way are what the miniature gas turbine builders use to fabricate their jet engines.

[KWILParticipant @kwil]

The real danger from flourescent tubes is not berylllium but Mercury in the phosphor powder (ie white powder). Check the recyling companies sites for their explanations.

Edited By KWIL on 10/04/2015 16:21:36

[MuzzerParticipant @muzzer]

Doesn't look as if beryllium is actually as bad as made out. It's no longer covered by EU RoHS restrictions, which rather underlines that.

"There is no inhalation risk associated with the massive forms in which the metal, alloys and ceramics are used. In order to contract CBD, an individual must be exposed to airborne beryllium in the form of a dust, mist or fume. This particulate must be small enough to reach the air sacs deep in the lungs and the individual must be sensitive to beryllium.

The carcinogenic risk associated with beryllium is by no means certain and recent studies strongly support a reclassification of beryllium as non-carcinogenic in humans. For purposes of risk analysis, it is necessary to be aware that the evidence for carcinogenicity which led to the current classification for beryllium has not been formally reviewed in over 15 years. Recent studies, which will be discussed below, have shed light on the question of beryllium carcinogenicity and have concluded that beryllium is not carcinogenic in humans or may at worst be an extremely weak carcinogen under conditions of massive airborne exposure levels not encountered since the 1940’s."

Interesting background here.

You'd have to do something pretty special to harm yourself on account of the BeO in a magnetron. You might cut yourself on the sharp edges of course….

Murray

[Ian S CParticipant @iansc]

One use for the magnets, take 2 bits of steel(mild as you can get), a triangle shape is good, put one each side of the magnet, and you have a magnetic welding support.

Ian S C

[martin perman 1Participant @martinperman1]

Twenty years ago, whilst working for a machine tool business, I had to go to a company in South Wales who manufactured Berylliium insulators, when I arrived on site I was asked if I had any clothes that could be destroyed and because I didnt I was issued with a paper suit, breathing hood and sealed gloves. The machines in the building were in negative pressure cabinets and were loaded by the operators through glass doors so air was drawn into the box. I had to fault find and replace circuit boards on a surface grinder with thick rubber gloves and when I finished I was hoovered down as I left the machine cabinet and then had to remove the suit and shower before putting my clothes back on.

When is was leaving site I asked the customer what happened to the machines when they were worn out and he pointed to JCB and a derelict site, all old plant was buried in the ground as they were not allowed to sell the machines because they couldnt guarantee that they were clean.

The next time the machines had a problem we would send spares and fix them over the phone as our company wouldnt send anybody else after me to fix them.

Martin P

[Tim StevensParticipant @timstevens64731]

Put a spare magnet on the rack where you keep your supplies of steel, then you can identify the stainless that got in with the mild by mistake.

Voice of experience calling …

Tim

[Bill PudneyParticipant @billpudney37759]

When I was involved with estimating a request for a quote arrived which required, amongst other things, the machining of Beryllium. At that time (early 1990s), the safety requirements were very, very extensive, to the extent that it wasn't worth our while setting up for what was basically a fairly small job. So I made some enquiries, there was no-one in Australia who was able to machine the material, i.a.w. the requirements. In fact the only place that I could find who would be prepared to take on the task, was the company that requested a quote from us!  As this rather defeated the point of the quotation, work on it was stopped at that point!

cheers

Bill

Edited By Bill Pudney on 15/04/2015 05:23:44

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