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martin perman29/03/2015 09:46:19
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2095 forum posts
75 photos

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

Les Jones 129/03/2015 10:03:28
2292 forum posts
159 photos

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 Theasby29/03/2015 10:06:23
615 forum posts
21 photos

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 Wood29/03/2015 10:16:52
2742 forum posts
39 photos

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

DMB29/03/2015 10:17:28
1585 forum posts
1 photos
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 C29/03/2015 10:31:54
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7468 forum posts
230 photos

dsc00839 (640xjpgI,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 Cdsc00683 (640x480).jpg

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

martin perman29/03/2015 11:24:33
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2095 forum posts
75 photos

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 Bannister09/04/2015 16:17:22
20 forum posts
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 udall09/04/2015 23:33:58
2032 forum posts
41 photos

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

wink 2

DMB09/04/2015 23:59:39
1585 forum posts
1 photos

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 Farr10/04/2015 00:06:47
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3988 forum posts
1799 photos
Posted by jason udall on 09/04/2015 23:33:58:

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

wink 2

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. indecision

Regards Nick.

Malcolm Bannister10/04/2015 00:57:10
20 forum posts

Hi John..

That's the stuff.

Cheers

Malcolm

Danny M2Z10/04/2015 06:30:25
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963 forum posts
2 photos

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 110/04/2015 09:30:12
314 forum posts

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 Gilligan10/04/2015 09:50:28
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23121 forum posts
1360 photos
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 Wyatt10/04/2015 12:41:40
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19226 forum posts
749 photos
86 articles

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

KWIL10/04/2015 16:13:41
3681 forum posts
70 photos

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

KWIL10/04/2015 16:21:09
3681 forum posts
70 photos

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

Muzzer10/04/2015 17:14:37
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2904 forum posts
448 photos

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 C14/04/2015 02:59:18
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7468 forum posts
230 photos

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

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