Do microwave ovens lose their oomph?

Muse

Lifer
Jul 11, 2001
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I was skating to my workout one day and spotted a microwave on the curb. It was still their on the way home, and having read a post saying microwaves have big cool magnets, I figured that I could pillage it for the magnet. I assumed it didn't work. Well, it's actually a pretty nice MWO, similar to the one in my kitchen (same glass turntable), and it's working, but it doesn't seem to have the power of my other one. Do they lose their effectiveness over time? IOW, should I just open it, take the magnet and throw out the rest?
 

gururu

Platinum Member
Jul 16, 2002
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their radioactive core is constantly losing radioactivity with time, so yes.

(I've been known to be wrong before) :p
 

dman

Diamond Member
Nov 2, 1999
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Originally posted by: Muse
I was skating to my workout one day and spotted a microwave on the curb. It was still their on the way home, and having read a post saying microwaves have big cool magnets, I figured that I could pillage it for the magnet. I assumed it didn't work. Well, it's actually a pretty nice MWO, similar to the one in my kitchen (same glass turntable), and it's working, but it doesn't seem to have the power of my other one. Do they lose their effectiveness over time? IOW, should I just open it, take the magnet and throw out the rest?

They have problems like every other appliance. Search google on Microwave oven repair, I believe there are quite a few links on the subject.
 

EagleKeeper

Discussion Club Moderator<br>Elite Member
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Oct 30, 2000
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Usually the magnitron will die. At that point it is cheaper to replace the unit than the part.

Replacing the mag used to require breaking the radioactive shielding.
 

Rumpltzer

Diamond Member
Jun 7, 2003
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Electromagnetic pulse bomb a la Oceans 11. :D

Google it for instructions.

edit - oh, and don't kill yourself in the process! ;)
 

Muse

Lifer
Jul 11, 2001
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Originally posted by: gururu
their radioactive core is constantly losing radioactivity with time, so yes.

(I've been known to be wrong before) :p

Uh, I doubt there's any radioactive material in a MWO. There would be shielding against radiation, microwave radiation, that is. That's an issue with MWO's - the seal on the door can be compromised, resulting in people being exposed to dangerous levels of MW radiation. Waitresses, etc. have been known to lose their eyebrows, etc., and undoubtedly had their odds of developing cancer elevated because the seals on the doors have deteriorated or been compromised by food residues, stuff like that. Even a new MWO has radiation issues (apart from MW radiation) - electromagnetic fields, generally in the neighborhood of 2-6 milligauss 2-6 feet from the oven, so it's a good idea not to stand close to the thing while it's doing its thing. Those levels aren't very dangerous, but it's still a good idea to limit your exposure to them if given the option. But radioactive materials with a 1/2 life? I don't think so.

My question is still whether a MWO will lose some of its ability to MW things. IOW, this thing seems to take twice as long to heat a cup of water as my other one. Do magnetrons just up and die or do they slowly lose their effectiveness?
 

Muse

Lifer
Jul 11, 2001
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Originally posted by: DrPizza
magnitron <> magnet.
Big cool magnitron. No magnets.

Ah, I guess I was misinformed. I've yet to tear one open looking for the cool magnet. I guess you saved me a bad experience.
 

Muse

Lifer
Jul 11, 2001
39,326
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Originally posted by: DrPizza
magnitron <> magnet.
Big cool magnitron. No magnets.

Quote: The MAGNETIC FIELD is provided by strong permanent magnets, which are mounted around the magnetron so that the magnetic field is parallel with the axis of the cathode.

Link
 

TheNinja

Lifer
Jan 22, 2003
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I remember one time I got inside one for a couple seconds. It was sweet!

Oh and I don't really know the answer to your question, sorry.
 

Vincent

Platinum Member
Oct 9, 1999
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Microwave ovens have different wattage ratings. So the one that you found may simply have a lower wattage rating than the one you already had. This would explain why your new microwave takes longer to heat up a cup of water.
 

funboy6942

Lifer
Nov 13, 2001
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LOL radioactive oven called a microwave oven powered by its radioactive core.
Its called a "microwave" oven because it uses, get this, microwaves :p
 

WW

Golden Member
Jun 21, 2001
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yes, there are big cool magnets on a magnetron...but, be really careful, that high voltage (4Kv) can kick you pretty good. About a dozen people a year die working on microwave ovens...try not to be one of them.

Make sure that big capacitor is discharged...or BOOM

magnetrons can get weaker as they age, but maybe it's just a low powered model..check the label..or measure it:

mw power test

 

thomsbrain

Lifer
Dec 4, 2001
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well what's the wattage of the microwave? if it's like 600 watts, then yeah, it's going to take forever to heat something.
 

Muse

Lifer
Jul 11, 2001
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Originally posted by: Vincent
Microwave ovens have different wattage ratings. So the one that you found may simply have a lower wattage rating than the one you already had. This would explain why your new microwave takes longer to heat up a cup of water.

Well, the one I have in the kitchen is 13.5 amps and this suspect one is 12 amps. But I think it's way less the 12/13.5 efficiency. IOW, if it takes 30 seconds for a cup of water to get to 80 C in the first, it's taking twice as long on this "new" one. Guess I'll tear it open for those prize magnets. But first, I'll unplug it and let it sit for a couple weeks so the capacitors discharge.:cool:
 

DrPizza

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Mar 5, 2001
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Wow. I guess I was wrong. I just don't remember there being any decent magnets in the 2 microwaves I've taken apart (to get to the other really cool thing: The big capacitor. ;) )
Careful with that cap though!
 

funboy6942

Lifer
Nov 13, 2001
15,311
395
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Best I can remember caps dont loose thier discharge over time. I used to mess around with little ones by hold a 9volt to thyem and the attaching a small toy motor to it and even after a week or so the small one still had a full charge to power the motor. That big sucker is going to pack a puch enough to kill you so I wouldnt reccomend messing with it till you figure out how to properly discharge it or just leave it be and go find some old hdd's to pull mags from :)
 

Muse

Lifer
Jul 11, 2001
39,326
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Originally posted by: funboy42
Best I can remember caps dont loose thier discharge over time. I used to mess around with little ones by hold a 9volt to thyem and the attaching a small toy motor to it and even after a week or so the small one still had a full charge to power the motor. That big sucker is going to pack a puch enough to kill you so I wouldnt reccomend messing with it till you figure out how to properly discharge it or just leave it be and go find some old hdd's to pull mags from :)

Ah, there are permanent magnets in "old HDD's?" How so? I have a few old HDs. 120 MB, 220 MB, 410 MB, 2.5 GB, 8 GB...

There must be a way to discharge big capacitors safely, eh?
 

Muse

Lifer
Jul 11, 2001
39,326
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Originally posted by: DrPizza
Wow. I guess I was wrong. I just don't remember there being any decent magnets in the 2 microwaves I've taken apart (to get to the other really cool thing: The big capacitor. ;) )
Careful with that cap though!

What do you do with that cap?
 

funboy6942

Lifer
Nov 13, 2001
15,311
395
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Originally posted by: Muse
Originally posted by: funboy42
Best I can remember caps dont loose thier discharge over time. I used to mess around with little ones by hold a 9volt to thyem and the attaching a small toy motor to it and even after a week or so the small one still had a full charge to power the motor. That big sucker is going to pack a puch enough to kill you so I wouldnt reccomend messing with it till you figure out how to properly discharge it or just leave it be and go find some old hdd's to pull mags from :)

Ah, there are permanent magnets in "old HDD's?" How so? I have a few old HDs. 120 MB, 220 MB, 410 MB, 2.5 GB, 8 GB...

There must be a way to discharge big capacitors safely, eh?

Yes all hdd have the pem mags in them. Just take them apart and get them out. Strong as all get up too :)
They may look small but dont let the size fool you and watch your fingers. I have been pinched alot by mine getting between the mag and metal. Infact I have a few that is so strong I can place the mag on one side of my hand and metal on the other and they both are stuck to my hand. Then for fun freak people out moving the mag as the metal moves on the other side of my hand.

Not to mention a hell of a lot safer then pulling apart a microwave to get it out.
 

Spencer278

Diamond Member
Oct 11, 2002
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Originally posted by: Muse
Originally posted by: funboy42
Best I can remember caps dont loose thier discharge over time. I used to mess around with little ones by hold a 9volt to thyem and the attaching a small toy motor to it and even after a week or so the small one still had a full charge to power the motor. That big sucker is going to pack a puch enough to kill you so I wouldnt reccomend messing with it till you figure out how to properly discharge it or just leave it be and go find some old hdd's to pull mags from :)

Ah, there are permanent magnets in "old HDD's?" How so? I have a few old HDs. 120 MB, 220 MB, 410 MB, 2.5 GB, 8 GB...

There must be a way to discharge big capacitors safely, eh?

Connect a resitor to both ends of the capacitor. The larger the resistor the slower the capacitor will discharge.
 

Muse

Lifer
Jul 11, 2001
39,326
9,225
136
Originally posted by: Spencer278
Originally posted by: Muse
Originally posted by: funboy42
Best I can remember caps dont loose thier discharge over time. I used to mess around with little ones by hold a 9volt to thyem and the attaching a small toy motor to it and even after a week or so the small one still had a full charge to power the motor. That big sucker is going to pack a puch enough to kill you so I wouldnt reccomend messing with it till you figure out how to properly discharge it or just leave it be and go find some old hdd's to pull mags from :)

Ah, there are permanent magnets in "old HDD's?" How so? I have a few old HDs. 120 MB, 220 MB, 410 MB, 2.5 GB, 8 GB...

There must be a way to discharge big capacitors safely, eh?

Connect a resitor to both ends of the capacitor. The larger the resistor the slower the capacitor will discharge.

It won't burn out the capacitor? I have a ~45 Ohm 5 watt resistor, I think. That will probably work, I guess.

So, what can I do with a big capacitor? :D
 

Muse

Lifer
Jul 11, 2001
39,326
9,225
136
Originally posted by: funboy42
Originally posted by: Muse
Originally posted by: funboy42
Best I can remember caps dont loose thier discharge over time. I used to mess around with little ones by hold a 9volt to thyem and the attaching a small toy motor to it and even after a week or so the small one still had a full charge to power the motor. That big sucker is going to pack a puch enough to kill you so I wouldnt reccomend messing with it till you figure out how to properly discharge it or just leave it be and go find some old hdd's to pull mags from :)

Ah, there are permanent magnets in "old HDD's?" How so? I have a few old HDs. 120 MB, 220 MB, 410 MB, 2.5 GB, 8 GB...

There must be a way to discharge big capacitors safely, eh?

Yes all hdd have the pem mags in them. Just take them apart and get them out. Strong as all get up too :)
They may look small but dont let the size fool you and watch your fingers. I have been pinched alot by mine getting between the mag and metal. Infact I have a few that is so strong I can place the mag on one side of my hand and metal on the other and they both are stuck to my hand. Then for fun freak people out moving the mag as the metal moves on the other side of my hand.

Not to mention a hell of a lot safer then pulling apart a microwave to get it out.
Will all HD's have pretty much equally strong magnets? Like I say, I have 120 MB, 220 MB, 410 MB, 2.5 GB, 8 GB, (and bigger). I love strong magnets. Very handy.
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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I lost a good 50 IQ reading this thread.

There is no radioactive.. anything.. in a microwave oven.

Microwaves do not "leak" through "faulty door seals". Infact, most microwaves don't have any sort of "door seal". The wavelength is too large to fit through any hole larger than what, 1cm?

It's spelled magnetron.

Are you sure the two units are of the same wattage?

Yes, all HDDs have strong neodymium magnets in them.

Got magnets?