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I took apart a Kenmore microwave in order to salvage the magnetron, transformer, and the HV capacitor. The transformers, HV capacitor, and the magnetron from the microwave are intact. Is it possible to make the magnetron work without the microcomputer panel?

JRE
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Sigma6RPU
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    Yes. If you look closely at the microcontroller panel you will see that it uses just a few wires to the transformer, whose secondaries then heat the filament and power the electrodes. It's pretty much just an ON/OFF thing. And no, you do NOT want to do that. Safer useful things can be done with the transformer core, for example. And the magnets from the magnetron can be removed intact, too. Seems like you are running around into dangerous places (HV TV section, microwave oven innards, etc.) – jonk Aug 07 '16 at 02:07
  • @jonk, that's a good answer. If you post it as an answer, I'd vote for it :) – bitsmack Aug 07 '16 at 02:33
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    **BAD IDEA!** First of all the power supply puts out -1,200vdc at about 10 amps. Touch it and you will loose a finger. Second thing is that an open magnetron tube will cook you and anyone nearby with microwaves, and metal objects will have arcs of mini lightning bolts coming off of them. Suggest you find a hobby that you will survive. –  Aug 07 '16 at 03:19
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    @sparky: Now he's going to DEFINITELY play with the transformer. ;) I may as well go to the TV horizontal/vertical coil question he had before this and clue him into how to bend a hanger wire to make a Jacob's ladder from the +anode, now. – jonk Aug 07 '16 at 03:35
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    @jonk. I find it disturbing that people want to experiment with lethal stuff, usually HV supplies with high current available. Yes I was shocked by the anode wire on old TV's a few times, and a 800vdc supply burned holes in my left wrist about 10 years ago, but this is nothing compared to 1200vdc @ 10 amps, as a charge on a capacitor. Mistakes at this level of power are painful, if not lethal. That is my main fear-they cannot make one mistake, or they will lose something dear to them. I wish there was a closing flag for "Lethal Hazards" if the OP is not competent enough to build it safely. –  Aug 07 '16 at 03:47
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    @sparky: Youth needs to have more than "someday you will be glad you learned about curl and divergence" to go bang their heads on a wall. They need light, action, smoke, fire, etc. The job of wiser heads is to figure out how to provide the one to help gain the other, I sometimes think. To mitigate risk, but not to completely avoid it. In this case, it would help that the OP has someone there to reduce the odds that the bad things happen while also providing the incentives to keep learning along the way. It's a tricky path to walk at times. – jonk Aug 07 '16 at 03:51
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    For example, those microwave transformer cores can be used to wind an arc welder. The currents will be usably high and the voltage safely low (20-30V or so.) That might be one of those fire and light things to suggest, I suppose. – jonk Aug 07 '16 at 03:55
  • @jonk. All we can do is issue dire warnings and hope they take safety first. We can offer answers as well, but steer them in a safe direction. They are going to do as they please anyways, just for entertainment, and bragging rights. The onus is on them in terms of safety. –  Aug 07 '16 at 04:01
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    @sparky: He may consider the arc welder idea. It will take some time, though it is within the means of most folks, he'll learn some good stuff along the way, and may get a nice tool to access still more skill development. (I'm getting chat reminders now from stackexchange.) – jonk Aug 07 '16 at 04:08
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    +1 - good question :-). As others have said.** YES** its easy enough but **NO NO NO - DO NOT do that. do NOT** | [**Them that die'll be the lucky ones.**](http://comicsradio.blogspot.co.nz/2008/11/them-that-dies-will-be-lucky-ones.html) | To the other hazards add the just maybe risk of XRAY generation by HV You REALLY do not want to encounter XRAYS. | RF from a magnetron can cook you invisibly and well. XRAYS are hard radiation, do genetic damage, and can make you sick enough to be pleased to die, worst case. BUT you are more likely to cook, burn and electrocute yourself. – Russell McMahon Aug 07 '16 at 15:01
  • To everybody who commented thanks for the advice, and @jonk I have already experimented with a Tesla coil, and used it in a science fair, and Jacob's Ladder look fun, not mention using a Van de Graff Generator. I am currently trying to build a shield (probably a Faraday's Cage) to protect myself from the radiation. I have the microwave's Faraday's cage but I wanna make a bigger one since I wanna make use the magnetron as a science fair project. – Sigma6RPU Aug 07 '16 at 15:58
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    Hopefully, you have some good advisors. When I was a teenager, I made nitroglycerin, mercury fulminate crystals, and lots of fireworks and explosives. I built telescopes and even designed one. I designed and made rocket nozzles and tested dozens of fuels over time. All this before I started college. I did this without anyone to help, so I spent long hours in a science library at the local university to educate myself before attempting things. I do understand the need to balance risk and education and not to completely avoid risk. You can't learn if you take no risks, imo. Good luck! – jonk Aug 07 '16 at 18:49
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    Very late addition to this, but the magnetron is also dangerous in another way: many magnetrons contain a ceramic element (I'm not sure what its purpose is) made of beryllium oxide, which is extremely toxic and carcinogenic if broken. – Hearth Jul 12 '19 at 21:53

3 Answers3

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Unfortunately, it is possible to make the magnetron work outside the oven, but as the comments have said, this is a really bad idea. Do not fire up a magnetron after removing it from an oven.

You recall what a microwave oven is designed to do? Heat food! Do you know what you are? A big bag of food.

If you are lucky, you might discover this with your hand. The skin has nerves, and a cooling blood supply, and you'd probably spot it warming long before the proteins begin to denature. If you are unlucky, you might discover this with your eye. The cornea has no nerves and no blood supply, and you'd probably spot it first with your vision going cloudy, as it does exactly what egg white does when you heat it. This would be permanent.

In terms of life-changing injuries, it's even more dumb than messing with lasers without goggles. Do not fire up a magnetron after removing it from an oven.

It's quite easy to take a magnetron apart with a screwdriver and a pair of cutters to release the two ferrite magnets. These are strong enough to be fun, without the bone-crushing danger of neodymiums, but they can still give a fold of skin a nasty nip, so keep them away from 8 year olds (sorry my daughter!)

Before you power up anything removed from the microwave, let me review different, safer, sources of high voltage, and the effects of their limited current or energy on the human body.

TV flyback - very limited current, painful shock
TV tube, charged - very limited energy, painful shock
Auto ignition coil - very limited energy, painful shock
Neon sign transformer - fairly limited low current, serious shock, but probably survive
Microwave oven transformer - high enough voltage to jump through clothes, currents to one amp, serious shock, probably die

Neil_UK
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    To further underscore the point, **microwave ovens are the most dangerous consumer products to service**. – jbarlow Aug 07 '16 at 09:46
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Just DON'T. I was a radar technician in the Navy and was once shocked by a home microwave magnetron. I will refrain from using my Navy speak as to how it felt but will say it HURT and my vocabulary was laced with salty language. I had someone rush me for an EEG or EKG or something in case there was damage. I didn't want to die on the basement floor for being stupid. I never made that mistake again.

Whammer USN
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If you must, the safest way to do it would be to make a power supply by pulsing a car ignition coil, arranged so it puts out a negative voltage to the cathode. You will need something like a scope soldering iron transformer for the filament, which takes 3.3V & about 11A. If you want a smooth output, you will need a capacitor rated at more than 4kV and a string of at least 5 1N4007 diodes as well.

The other option is a 7.5KV neon sign transformer and a bridge of 4 strings of at least 5 1N4007s. Neon sign transformers are rated at o/c voltage & s/c current, &, as far as I was able to find out, a 30mA transformer produces about 26mA at a tube voltage of 1/2 the transformer o/c voltage, so it will give you about 24.4 mA rms (about 22mA av) at 4kV. Magnetrons normally run at about 300mA, so it will produce about 1/14 of the normal output power. Keep it away from your eyes though. Check out Neil-UK's advice above.

Peter R. McMahon
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