Safe to disassemble a microwave oven?
Richard M.
J. Zeigler wrote:
>
> EG wrote:
> >
> > Is it safe to allow a child, familiar with disassembling computers and
> > household electronics, to disassemble a microwave oven?
> >
> > Or are there dangerous components inside?
> >
> > Any advice will be appreciated. Thanks.
> >
> > EarlPersonally I wouldn't. You've got mains (110) coming in and probably
> some pretty high voltages on the maggi (vacuum tube that generates the
> microwaves).
You don't actually think they meant while energized!!
Even if you did, you only need advise against doing it while it is
powered or even connected to the line.
--
"Nobody ever went broke underestimating
the intelligence of the American public."
Richard G. Mainar Digi...@serv.net
Richard M.
EG wrote:
>
> Is it safe to allow a child, familiar with disassembling computers and
> household electronics, to disassemble a microwave oven?
>
> Or are there dangerous components inside?
>
> Any advice will be appreciated. Thanks.
>
> Earl
You should define "child," because the very word tell me he/she should
not be doing it unsupervised.
However, to speak to the issue of the MW and it containing dangerous
components: As long as the unit is not plugged in and the powersupply
is discharged, there is nothing that will harm you. PROVIDED...
*PROVIDED*... you do not allow the klystron or magnetron to be opened.
It will not fall apart on its own, but some of the units use Beryllium
or other hazardous metals in their construction.
EG
J. Zeigler
Don Klipstein
EG (emp...@comet.net) wrote:
: Is it safe to allow a child, familiar with disassembling computers and
: household electronics, to disassemble a microwave oven?
:
: Or are there dangerous components inside?
:
: Any advice will be appreciated. Thanks.
: Earl
Microvave ovens have high voltage capacitors, that get charged to maybe
a few thousand volts. Especially if something has gone wrong, there is a
possibility that these capacitors may remain charged even if the microvave
is turned off and unplugged.
Please note that if a charged capacitor is briefly shorted, it can
recover a small portion of the initial charge due to "dielectric
absorption". In the case of a microwave, this means a possibility of the
capacitor having a shocking voltage after being supposedly discharged.
Please also note that a shock, even if not fatal, can cause its victim
to involuntarily bump into things. If this occurs with anything that is
live, this has the danger of causing another shock. If this occurs with a
TV or a monitor, this may result in a dangerous picture tube implosion.
For some additional info on do-it-yourself repair of appliances and home
electronics, check out Filip G.'s web site:
http://www.paranoia.com/~filipg/
- Don Klipstein (d...@misty.com or klip...@netaxs.com)
http://www.misty.com/~don/index.html
sokos mark
In article <Dyvr...@murdoch.acc.Virginia.EDU>, EG <emp...@comet.net> wrote:
>Is it safe to allow a child, familiar with disassembling computers and
>household electronics, to disassemble a microwave oven?
Nope. Computers are board level things, low voltage, with sealed power
supplies that are designed to be modular. Unless you do something really
stupid, it is hard to hurt yourself diddling with computer guts (easy
to foul up your computer, but relatively hard to hurt yourself). If they
can explain all of the hazards of opening up a power supply, why a
capacitor makes an excellent arc welder when combined with that screwdriver
in your hand (zap!) and can give you a fairly detailed description of which
parts they can and cannot touch inside the microwave, then sure, they
can open it up.
btw, "child" is an awfully vague term... (8 years old? 14? Big difference)
>Or are there dangerous components inside?
Well, in all likelihood they could muck around a bit without harm, but
I wouldn't take chances with a child. The rule is "if you don't know
what you are doing, keep your hand in your pocket".
There's probably not much of interest in there anyways. A microwave
just uses a magnetron to generate the microwaves (same as the old
radar sets from way back when) and a waveguide to shove the wave into
the box where the food is. There may be a digital board controlling
when the thing turns on and off, or you may have one of those cheapie
but almost worthless mechanical dials. Improper reassembly of the RF
stuff could cause the thing to leak RF while in use, which would not
be a good thing.
It would probably be ok to take the cover off and take a look, as long
as the child doesn't mess with any of the guts. This will probably
satisfy the child's curiosity. If they know how to rip apart a computer,
they should have no problem getting the cover off and back on safely.
I'm assuming they just are curious about how the thing works. Have
them go to the library and look up "magnetron". If you can't find
anything decent, drop me an e-mail and I'll try to give a good description
that a child can understand.
>Any advice will be appreciated. Thanks.
>Earl
- Mark Sokos (mso...@gl.umbc.edu) http://www.gl.umbc.edu/~msokos1
Electrical engineer, computer geek (er, programmer), no-talent bum musician
(have bass, will travel), and perpetual student
zapper
In article <Dyvr...@murdoch.acc.Virginia.EDU>, EG <emp...@comet.net> wrote:
>Is it safe to allow a child, familiar with disassembling computers and
>household electronics, to disassemble a microwave oven?
>
>
>
>Earl
>
WHY would ANYONE allow a CHILD to disassemble anything like that !!!! What a
stupid fuck! If you have to ask a question like that you need to learn some
parenting skills.
Sorry if I sound harsh, I just cant belive the question !!!
zapper
-----------------------------------------------------
"There's nothing you can do with a dedicated misfit."
The Robot, Lost in space.
-----------------------------------------------------
Sam Goldwasser
In article <539psl$5...@news.misty.com> d...@Misty.com (Don Klipstein) writes:
> EG (emp...@comet.net) wrote:
> : Is it safe to allow a child, familiar with disassembling computers and
> : household electronics, to disassemble a microwave oven?
> :
> : Or are there dangerous components inside?
> :
> : Any advice will be appreciated. Thanks.
> :
> : Earl
> Microvave ovens have high voltage capacitors, that get charged to maybe
> a few thousand volts. Especially if something has gone wrong, there is a
> possibility that these capacitors may remain charged even if the microvave
> is turned off and unplugged.
> Please note that if a charged capacitor is briefly shorted, it can
> recover a small portion of the initial charge due to "dielectric
> absorption". In the case of a microwave, this means a possibility of the
> capacitor having a shocking voltage after being supposedly discharged.
> Please also note that a shock, even if not fatal, can cause its victim
> to involuntarily bump into things. If this occurs with anything that is
> live, this has the danger of causing another shock. If this occurs with a
> TV or a monitor, this may result in a dangerous picture tube implosion.
> For some additional info on do-it-yourself repair of appliances and home
> electronics, check out Filip G.'s web site:
The cap (usually only one, a metal roughly cylindrical object with terminals
at one end) is the only dangerous electrical component but should discharge
itself in a few minutes after the oven is turned off (and unplugged!).
Shorting and then putting a clip lead across the terminals will assure
that it is discharged.
However, I wouldn't let a child (you didn't say what age or level of
knowledge) do this unsupervised. There is a lot of sharp sheet metal,
strong magnets in the magnetron, etc.
On the other hand, this would be a great educational experience (perhaps
for both of you) and with the proper supervision, safe.
> http://www.paranoia.com/~filipg/
Complete description of operation, repair, and precautions. Of course,
once you have read this, you may decide to fix it instead!
--- sam
Douglas W. Jones,201H MLH,3193350740,3193382879
From article <32585F...@homenet.ie>, by "J. Zeigler" <mic...@homenet.ie>:
> EG wrote:
>> Is it safe to allow a child, familiar with disassembling computers and
>> household electronics, to disassemble a microwave oven?
> EarlPersonally I wouldn't. You've got mains (110) coming in and probably
> some pretty high voltages ...
Of course, if you unplug it first (and leave it unplugged long enough for
any HV capacitors to leak down to nothing) you could eliminate EG's
concern.
Doug Jones
jo...@cs.uiowa.edu
+------------------------------------------------------------------------+
| 5 milliamps at 5000 volts won't kill you, but 25 watts dissapated in |
| the small volume of skin where the spark hits you will blow a nice |
| little crater, and the smell of vaporized flesh is something you won't |
| quickly forget. |
+------------------------------------------------------------------------+
Gary Tait
On Mon, 7 Oct 1996, EG wrote:
> Is it safe to allow a child, familiar with disassembling computers and
> household electronics, to disassemble a microwave oven?
>
> Or are there dangerous components inside?
>
> Any advice will be appreciated. Thanks.
>
> Earl
It sould be ok if 1: The HV capacitors are discharged (they usually have
an internal bleeder resistor ), 2: The child will not be using the parts
to generate microwaves (either in the oven or outside).
Gary Tait , VE3VBF
John Lull
In the waning years of the 20th century, z...@mhv.net (zapper) wrote
(with possible deletions):
> WHY would ANYONE allow a CHILD to disassemble anything like that !!!!
(rant deleted)
Because children need to learn. Taking things apart can be a good way
of doing that.
There are very few dangerous components inside a microwave, and it is
relatively easy to protect a child willing to follow directions from
the hazards there are.
Dan Mills
>WHY would ANYONE allow a CHILD to disassemble anything like that !!!! What a
>stupid fuck! If you have to ask a question like that you need to learn some
>parenting skills.
>Sorry if I sound harsh, I just cant belive the question !!!
Sorry, I have to disagree,
Provided you discharge the capacitor (And clip a short across it!)
There is little that is dangerous in a microwave. Do not let them
disassemble the Maggie as it could contain BeO which is a bad thing.
Also do not let them add the power transformer to their junk box,
as it will step the incomming power up to several thousand volts.
Other then that there is little to worry about.
Children love to take equipment apart (Thats how they learn!) I would
consider that the risk inherent in dissassembling almost any object
(Whithin reason) to be worth taking if the child is curious about it.
Just my thoughts.
--
**************************************************************
* And on the first day the lord said....... * *
* ... LX1, GO! and there was light. * Dan Mills. *
**************************************************************
Sam Goldwasser
In article <53aom5$o...@news.mhv.net> z...@mhv.net (zapper) writes:
> In article <Dyvr...@murdoch.acc.Virginia.EDU>, EG <emp...@comet.net> wrote:
> >Is it safe to allow a child, familiar with disassembling computers and
> >household electronics, to disassemble a microwave oven?
> >Or are there dangerous components inside?
> >Any advice will be appreciated. Thanks.
> >Earl
> WHY would ANYONE allow a CHILD to disassemble anything like that !!!! What a
> stupid fuck! If you have to ask a question like that you need to learn some
> parenting skills.
> Sorry if I sound harsh, I just cant belive the question !!!
While I agree with you to some extent, what did you take apart when you
were a kid? How did you learn? I, for one, took apart (and eventually
learned to put the stuff back together) nearly anything I could get my
hands on.
Once the HV capacitor is discharged, a microwave is relatively harmless except
for sharp sheet metal. For someone with a bit of electronics knowledge, parts
of it like the controller can even be useful for other projects.
--- sam
> zapper
Richard M.
zapper wrote:
> WHY would ANYONE allow a CHILD to disassemble anything like that !!!! What a
> stupid fuck! If you have to ask a question like that you need to learn some
> parenting skills.
> Sorry if I sound harsh, I just cant belive the question !!!
>
>
> -----------------------------------------------------
> "There's nothing you can do with a dedicated misfit."
> The Robot, Lost in space.
> -----------------------------------------------------
No, you don't sound harsh... you sound like a blithering, ranting,
idiot. But you already knew that and decided to post in spite of it.
Anthony S. Pelliccio
In article <844704...@abcde.demon.co.uk>,
Dan Mills <Dmi...@abcde.demon.co.uk> wrote:
>
>Children love to take equipment apart (Thats how they learn!) I would
>consider that the risk inherent in dissassembling almost any object
>(Whithin reason) to be worth taking if the child is curious about it.
>
>Just my thoughts.
I have to agree with that statement. As a kid I had this thing about
taking ANYTHING I could get my hands on apart. As I got older I learned
how to put them back together. I think my favorite things to take apart
were old telephones and radios. I remember the old 500 and 2500 sets
where they sunk the NI into this gunk to keep the caps from drying out.
That stuff was a real pain to get unstuck from various surfaces and
the likes of skin.
Tony
Mark Zenier
in <32591a63...@news.earthlink.net>, John Lull wrote:
: In the waning years of the 20th century, z...@mhv.net (zapper) wrote
: (with possible deletions):
: > WHY would ANYONE allow a CHILD to disassemble anything like that !!!!
: (rant deleted)
: Because children need to learn. Taking things apart can be a good way
: of doing that.
: There are very few dangerous components inside a microwave, and it is
: relatively easy to protect a child willing to follow directions from
: the hazards there are.
There are very few components inside of a microwave oven and ALL of
them are dangerous if power is applied. You've got a transformer
that'll provide 2.5 kV at 200-500 milliamps. And a capacitor that
will BITE if it's charged up.
Is everything on your workbench capable of insulating that if the kid
got really interested in seeing what happens if that transformer got
plugged in?
Even the pro's get killed working on these things. They're not
that much different from a 1 KW RF linear amplifier. Read the
Safety sections in one of the newer editions of the "ARRL Handbook
for Radio Amateurs".
Mark Zenier mze...@eskimo.com mze...@netcom.com
Chris Guli
Tim Shoppa wrote:
>
> In article <53a03e$j...@umbc9.umbc.edu>, sokos mark <mso...@umbc.edu> wrote:
> >In article <Dyvr...@murdoch.acc.Virginia.EDU>, EG <emp...@comet.net> wrote:
> >>Is it safe to allow a child, familiar with disassembling computers and
> >>household electronics, to disassemble a microwave oven?
> >
> >supplies that are designed to be modular. Unless you do something really
> >stupid, it is hard to hurt yourself diddling with computer guts (easy
> >to foul up your computer, but relatively hard to hurt yourself).
>
> power supply in it :-). If you short it out with a ring
> and amputate your finger, at least it instantly cauterizes the
> wound.
>
> Tim. (sho...@triumf.ca)
What do you have, a CRAY ? I don't know any PERSONAL computer that has a
1750-watt power supply !!
--
The GNU math: LinuX * X = Linux²
J. Zeigler
Richard M. wrote:
>
> J. Zeigler wrote:
> >
> > EG wrote:
> > >
> > > Is it safe to allow a child, familiar with disassembling computers and
> > > household electronics, to disassemble a microwave oven?
> > >
> > >
> > > Any advice will be appreciated. Thanks.
> > >
> > microwaves).
>
> Even if you did, you only need advise against doing it while it is
> powered or even connected to the line.
>
Neither of which will guarantee there is no shock hazard.
No, actually I was assuming the unit was uplugged but that the incoming
voltage would have been rectified and stored on capacitors. If the
microwave is being torn apart I have to assume it probably didn't work
anymore. Without knowing why I automatically assume that bleeder
resistors may be open and capacitors remain charged. Since the age of
the child and its experience level weren't stated, I tend to assume the
worst case scenario. I guess I used to see too many of the guys in the
service get a good shock from the delay line in an MG13 radar system on
the F101, and they knew what they were doing, supposedly.
Bill Rothanburg
Sam,
Sorry, but I have to disagree with you on this one. The last time I got
"bit" by a capacitor, it was in a microwave. The microwave had 'smoked'
(literaly, apparently the transformer had shorted). It had been unplugged a
good half hour before I tried pulling the lead to the cap.
Fortunately, the jolt left my heart and sense of humor intact.
Bill
In message <SAM.96Oc...@colossus.stdavids.picker.com> -
s...@stdavids.picker.com (Sam Goldwasser)07 Oct 1996 11:18:26 GMT writes:
:>
:>In article <539psl$5...@news.misty.com> d...@Misty.com (Don Klipstein) writes:
:>
:>> EG (emp...@comet.net) wrote:
:>> : Is it safe to allow a child, familiar with disassembling computers and
:>> : household electronics, to disassemble a microwave oven?
:>> :
:>> : Or are there dangerous components inside?
:>> :
:>> : Any advice will be appreciated. Thanks.
:>> :
:>> : Earl
zapper
If I am the idiot, why are YOU asking such a DUMB question???
(a) How old is this "child"?
(b) Assuming its a preeteen, why would anyone allow him/her do disassmble an
appliance?
(c) Just in the asking of the question proves you do not have the knowledge to
adequetly supervise the operation.
(d) If you do not like the response perhaps you souldnt have posted the
question.
Justin D. West
Douglas W. Jones,201H MLH,3193350740,3193382879 wrote:
>
> From article <32585F...@homenet.ie>, by "J. Zeigler" <mic...@homenet.ie>:
>
> >> Is it safe to allow a child, familiar with disassembling computers and
> >> household electronics, to disassemble a microwave oven?
>
>
> Of course, if you unplug it first (and leave it unplugged long enough for
> any HV capacitors to leak down to nothing) you could eliminate EG's
> concern.
>
Do you have enough life span to cover the years it would take to
discharge a HV
capacitor?
T.V. repairmen have been known to get themselves killed while working on
old
t.v's that haven't been on for a number of years. Why? Because the
caps hadn't
discharged completely.
That, and watch your jewliery (sp?) when working on electronics. One
fellow I
know just went to the hospital because a HV cap jumped to his watch, and
shocked
the living daylights out of him.
J...
John.D.W...@tek.com
In article <53a03e$j...@umbc9.umbc.edu> mso...@umbc.edu (sokos mark) writes:
>From: mso...@umbc.edu (sokos mark)
>Subject: Re: Safe to disassemble a microwave oven?
>Date: 7 Oct 1996 00:14:38 -0400
>In article <Dyvr...@murdoch.acc.Virginia.EDU>, EG <emp...@comet.net> wrote:
>>Is it safe to allow a child, familiar with disassembling computers and
>>household electronics, to disassemble a microwave oven?
>Nope. Computers are board level things, low voltage, with sealed power
>supplies that are designed to be modular. Unless you do something really
>stupid, it is hard to hurt yourself diddling with computer guts (easy
>to foul up your computer, but relatively hard to hurt yourself). If they
>can explain all of the hazards of opening up a power supply, why a
>capacitor makes an excellent arc welder when combined with that screwdriver
>in your hand (zap!) and can give you a fairly detailed description of which
>parts they can and cannot touch inside the microwave, then sure, they
>can open it up.
>btw, "child" is an awfully vague term... (8 years old? 14? Big difference)
The short answer is that it depends on the age and experience of the child.
About the only thing that is dangerous is the power supply capacitor, which
should be treated with great respect until it is discharged. If the child
doesn't know how to do that, don't open the cabinet. If the oven has not been
run for a long time, the capacitor probably has self-discharged by now, but
why take a chance? There is not all that much of interest in a microwave
oven anyway.
J. Winkelman
Richard M.
J. Zeigler wrote:
>
> Richard M. wrote:
> >
> > J. Zeigler wrote:
> > >
> > > >
> > > > Is it safe to allow a child, familiar with disassembling computers and
> > > > household electronics, to disassemble a microwave oven?
> > > >
> > > >
> > > > Any advice will be appreciated. Thanks.
> > > >
> > > microwaves).
> >
> > You don't actually think they meant while energized!!
> > Even if you did, you only need advise against doing it while it is
> > powered or even connected to the line.
> >
>
> Neither of which will guarantee there is no shock hazard.
>
> No, actually I was assuming the unit was uplugged but that the incoming
> voltage would have been rectified and stored on capacitors.
I don't buy your explanation. You didn't mention a thing about the HV
capacitor in your post about 110 volt mains comming in. Nor did you
suggest that that was the only possible hazard and it could easily be
eliminated by shorting the cap.
Sam Goldwasser
In article <325863...@serv.net> "Richard M." <digi...@serv.net> writes:
<snip>
> You don't actually think they meant while energized!!
> Even if you did, you only need advise against doing it while it is
> powered or even connected to the line.
Well, there is also the high voltage capacitor. This is supposed to discharge
in something like 30 seconds or less but bleeder resistors can fail open
and not result in any symptoms. Thus, discharging the capacitor should be
done whenever touching *anything* in the microwave power generation circuits.
Other than this, the only danger is sharp sheet metal.
See the Microwave Repair FAQ at:
http://www.paranoia.com/~filipg/HTML/REPAIR/ (in the USA)
mirrored at this URL in Italy:
http://ftp.cised.unina.it/pub/electronics/REPAIR/ (better for Non-USA)
for general and safety information.
--- sam (s...@stdavids.picker.com)
Sam Goldwasser
<snip>
> It will not fall apart on its own, but some of the units use Beryllium
> or other hazardous metals in their construction.
It is a magnetron and I don't think consumer microwave oven magnetrons would
contain any beryllium.
--- sam
Sam Goldwasser
> Personally I wouldn't. You've got mains (110) coming in and probably
> some pretty high voltages on the maggi (vacuum tube that generates the
> microwaves).
Certaily, wait until the dinner is cooked :-) See the many other postings
outlining the potential danger of the HV capacitor on unplugged ovens.
--- sam
Robert Ogburn
John Lull wrote:
In the waning years of the 20th century, z...@mhv.net (zapper) wrote
(with possible deletions):
Because children need to learn. Taking things apart can be a good way
of doing that.
Thanks, oh so true. So many people, so little learned.
Tim Shoppa
>>Is it safe to allow a child, familiar with disassembling computers and
>>household electronics, to disassemble a microwave oven?
>
>supplies that are designed to be modular. Unless you do something really
>stupid, it is hard to hurt yourself diddling with computer guts (easy
>to foul up your computer, but relatively hard to hurt yourself).
You're obviously assuming that my computer doesn't have a +5V 350Amp
zapper
>>Subject: Re: Safe to disassemble a microwave oven?
>The short answer is that it depends on the age and experience of the child.
>About the only thing that is dangerous is the power supply capacitor,
I guess that 4KV from the HV transformer dont count, huh......
Les Bartel
John.D.W...@tek.com wrote:
> why take a chance? There is not all that much of interest in a microwave
> oven anyway.
Perhaps not to you and me, but to a child, a great deal. (I was a child once
[my wife says I still am, sometimes.]) I'd say, depending on the age AND
ability of the child, cut off the power cord and remove the high voltage
capacitor. Then let him/her at it.
- les
Lee K. Gleason
>>
>> >> Is it safe to allow a child, familiar with disassembling computers and
>>
Does anyone know if any exotic metals are in the magnetron? Vacuum
tubes in the old days often contained thorium and beryllium...neither
of which would do you any good if you cracked 'em open...if the
maggy contains anything like that, I'd rather not have a kid open it
up to see what makes it work.
> Do you have enough life span to cover the years it would take to
> discharge a HV
> capacitor?
>
> T.V. repairmen have been known to get themselves killed while working on
> old
> t.v's that haven't been on for a number of years. Why? Because the
> caps hadn't
> discharged completely.
Years? Is there any documentation on this, besides "an old TV tech
told me"? ...I'm not saying it's not possible, but actual deaths from
years old TV caps sound very much like the tale grew in the telling...and
some of those old TV techs were known to tell a fishing story or two
to earnest young squirts...
Mind you, I don't dispute the absolute necessity to handle any circuit,
alive or dead with caution, and I would never proceed to work on one
of those old TV sets without making sure that the caps (and the leyden
jar formed by the picture tube) were discharged...it's just that
the story has an apochryphal ring to it...
Lee K. Gleason N5ZMR
Control-G Consultants
gle...@mwk.com
Richard M.
Lee K. Gleason wrote:
>
> >>
> >> >> Is it safe to allow a child, familiar with disassembling computers and
> >> >> household electronics, to disassemble a microwave oven?
> >>
>
> Does anyone know if any exotic metals are in the magnetron? Vacuum
> tubes in the old days often contained thorium and beryllium...neither
> of which would do you any good if you cracked 'em open...if the
> maggy contains anything like that, I'd rather not have a kid open it
> up to see what makes it work.
I posted to the thread about the beryllium hazard. read back, but let's
not run amuck with DANGER warnings. Have you efer tried to open a
magnetron? Also, why can't you just tell the kid not to try and for
what reason?
I really don't care for horror stories. The exceptions are not to be
used to substantiate new rules.
Joe Seymour
If your microwave is UL listed, and it probably is if it was sold in the US,
it has bleeder resistors on the capacitors. It never hurts to discharge
large caps, especially if the oven was malfunctioning. I've heard lots of
stories of people getting "bitten" by caps but I don't know of a single
fatal instance. You can get nice "arcs and sparks" from a large cap and a
screwdriver, but unless your kid plans to put a wet finger from each hand on
the capacitor leads, the risk is very low.
I don't know what exotic metals are in a microwave, but beryllium is safe to
handle. It is only a problem when heated; it can release a toxic gas but
this takes more than skin temperature, a closed environment, and a
sufficient amount of beryllium. If your kid is in the habit of eating metal,
I'd worry about a lot of things. The biggest risk is probably from slipping
with the screwdriver. I'd say that you should ask them a question, something
that they can discover, and let them go to it.
My opinion,
Joe S.
John 015
In article <SAM.96Oc...@colossus.stdavids.picker.com>,
s...@stdavids.picker.com (Sam Goldwasser) said:
>
>> You don't actually think they meant while energized!!
>> Even if you did, you only need advise against doing it while it is
>> powered or even connected to the line.
>
>Well, there is also the high voltage capacitor. This is supposed to discharge
>in something like 30 seconds or less but bleeder resistors can fail open
>and not result in any symptoms. Thus, discharging the capacitor should be
>done whenever touching *anything* in the microwave power generation circuits.
This reminds me of a 2200uF/450 Volt electrolytic capacitor
I charged up and then forgot about. Coming back six months
later it whacked me good. I didn't think electrolytics could
hold charge that long. Of course I don't know what voltage
it had dropped to at the time when I touched it's terminals.
John
John.D.W...@tek.com
In article <53epk4$o...@news.mhv.net> z...@mhv.net (zapper) writes:
>From: z...@mhv.net (zapper)
>Subject: Re: Safe to disassemble a microwave oven?
>Date: Wed, 09 Oct 96 02:55:15 GMT
>>>Subject: Re: Safe to disassemble a microwave oven?
>>The short answer is that it depends on the age and experience of the child.
>>About the only thing that is dangerous is the power supply capacitor,
>I guess that 4KV from the HV transformer dont count, huh......
>zapper
...............
Well, I'd assume the unit would not be plugged in and turned on when it was
being disassembled, but maybe that's assuming too much.
Uday Kamath
zapper (z...@mhv.net) wrote:
: In article <Dyvr...@murdoch.acc.Virginia.EDU>, EG <emp...@comet.net> wrote:
: >Is it safe to allow a child, familiar with disassembling computers and
: >Any advice will be appreciated. Thanks.
: >
: >Earl
: >
: WHY would ANYONE allow a CHILD to disassemble anything like that !!!! What a
: stupid fuck! If you have to ask a question like that you need to learn some
: parenting skills.
: Sorry if I sound harsh, I just cant belive the question !!!
Parenting skills, if you ask me this guy has excellent parenting skills,
They guy who wrote this is a dumbass who never felt the joy of opening
up appliances as a child. When I was a child 6 years>> my parents let
me open up all my old appliances, they made sure I didn't have anything
plugged in and stuff. Sometimes when they weren't looking I would plugg in
stuff and get a big spark and get a big shock but this would be part of
the experience. From about 6 -13 I used to open up everything and never
put things back together, I finally learned how to put things back together
and by the time I was 16 I could fix anything in the house, nowadays we
never spend 500$ to fix our TV, my mother just tells me she'll take me
out for dinner and the TV's fixed. My father wishes he still had that
old SW radio that I had opened up when I was 5, I would fix it now!!
Earl, go ahead, give him all your (inexpensive) stuff and let him look
inside, he will get a lot of experience. With a microwave I would
open it up with him, just because of the HV, If hes opened up a TV set
I would say this would fall under the same catagory!!
-Uday
<kam...@expert.cc.purdue.edu>
and putting them back together
g
: -----------------------------------------------------
Richard M.
J. Zeigler wrote:
<massive clip of drip>
> I did mention the high voltage on the maggi, any person with
>experience would realize
And therein lies the problem, Mr. Hindsight. This is a BASIC
electronics forum and the very question assures us that there is little
or no experience. Gawd! Are you that sightless?
Get over the fact that you gave poor advice because you didn't know how
benign a microwave can be when properly approached.
Your advice of staying away, taught nothing.
Mark Zenier
in <53hk8s$o...@canyon.sr.hp.com>, Joe Seymour wrote:
: I don't know what exotic metals are in a microwave, but beryllium is safe to
: handle. It is only a problem when heated; it can release a toxic gas but
: this takes more than skin temperature, a closed environment, and a
: sufficient amount of beryllium. If your kid is in the habit of eating metal,
: I'd worry about a lot of things. The biggest risk is probably from slipping
: with the screwdriver. I'd say that you should ask them a question, something
: that they can discover, and let them go to it.
It's not beryllium metal, but beryllium oxide ceramic insulators that
crumble into dust, given enough force. I don't know how easily it
is absorbed, but there are warning stickers on the packaging for
BeO insulators used for power transistors.
Mark Zenier mze...@eskimo.com mze...@netcom.com
J. Zeigler
Richard M. wrote:
>
> I don't buy your explanation. You didn't mention a thing about the HV
> capacitor in your post about 110 volt mains comming in. Nor did you
> suggest that that was the only possible hazard and it could easily be
> eliminated by shorting the cap.
>
You don't have to! Of course I didn't mention every possible hazard, I
just told him to stay out of it. But then again, you didn't either, in
fact all you suggested was he either turn it off first or unplug it. I
did mention the high voltage on the maggi, any person with experience
would realize that would require a step up transformer, rectification,
and a storage device (yeah, that means a cap). If the original poster
didn't have the means to understand what I said he certainly didn't
belong inside the unit. Most equipment of this nature has a label on it
saying no user-serviceable parts inside, and its there for good reason.
I guess you feel your advice that the kid dig around in there when you
don't know his age or experience level is sound service practice. I
think not.
J. Zeigler
Richard M. wrote:
>
> And therein lies the problem, Mr. Hindsight. This is a BASIC
> electronics forum and the very question assures us that there is little
> or no experience. Gawd! Are you that sightless?
Your right, and that's EXACTLY why I told them to stay out of it.
> Get over the fact that you gave poor advice because you didn't know how
> benign a microwave can be when properly approached.
And according to you turning off the power, OR unplugging it was
sufficient! Gawd help us!!!
> Your advice of staying away, taught nothing.
I wasn't trying to teach, I was suggesting that I wouldn't let my kid do
it, which I would not. I did say it was my personal opinion. If you
don't like it, don't use it.
David Moisan
jo...@sr.hp.com (Joe Seymour) wrote:
> If your microwave is UL listed, and it probably is if it was sold in the US,
>it has bleeder resistors on the capacitors. It never hurts to discharge
Joining the tail end of this thread, I've another suggestion:
If you're giving equipment to your kid or anyone else to scrap for
parts, cut the AC plug. That way the microwave or TV or whatever
won't be plugged in by accident by someone else. I'm sure that the
kid stripping the microwave would be told this, but another family
member might not realize it, to their great detriment.
I've given stuff to people (and kids!) to scrap and found this to be a
wise precaution. Yes, I did strip lots of TV's and such when I was
younger, too.
Dave
| David Moisan, N1KGH Email: dmo...@shore.net |
| WWW: http://www.shore.net/~dmoisan n1...@amsat.org |
| Invisible Disabilities Page: |
| http://www.shore.net/~dmoisan/invisible_disability.html |
Richard M.
J. Zeigler wrote:
>
> Richard M. wrote:
> >
> > And therein lies the problem, Mr. Hindsight. This is a BASIC
> > electronics forum and the very question assures us that there is little
> > or no experience. Gawd! Are you that sightless?
>
> Your right, and that's EXACTLY why I told them to stay out of it.
>
Thanks for conveniently ignoring the part of the response where I sated
you were the only one to offer such advise and actaully caught grief
from almost everyone eose for doing it. You're hard-headed and
impossible to reason with... I am very fortunate to NOT have had a
father like you. I learned much from my supervised tinkering.
J. Zeigler
>
>
> Thanks for conveniently ignoring the part of the response where I sated
> you were the only one to offer such advise and actaully caught grief
> from almost everyone eose for doing it. You're hard-headed and
> impossible to reason with... I am very fortunate to NOT have had a
> father like you. I learned much from my supervised tinkering.
>
I didn't you didn't read the additional post. Included are 11
attachments that supported my position.
Your statement is interesting, first I'm the 'only one' and then in the
same sentence 'caught grief from almost everyone', make up your mind.
The only one that gave me any grief was you, the rest of the group
that did disagree simply stated their case for letting the kid into the
microwave to tinker. You at best seem to have to engage in personal
attacks and I'm not the only one you have done this with. You don't
reason, to always drop down to a personal attack. Your comment in this
post I'm responding to is a prime example. Mis-state a fact, then follow
up with a personal attack. Grow up!
I notice that you still haven't responded as to your qualifications. Oh
well, I didn't really expect you would anyway.
I'm happy that you had supervised tinkering. From the nature of the
original post that started this thread, it was very clear that the
gentleman asking the question didn't have the background to supervise,
that was why he asked the question. As for not being your father,
Thank God, I've been blessed. My 4 boys are all well behaved and don't
stoop to personal attacks to try and make their arguments. They rely on
facts they can prove.
Your post and this one have nothing to do with electronics, I would
suggest that if you have further things to say on this thread you do it
via email, and quit bothering the rest of the group with this trash,
however its up to you.
Kent A Vander Velden
>>>Subject: Re: Safe to disassemble a microwave oven?
>>The short answer is that it depends on the age and experience of the child.
>>About the only thing that is dangerous is the power supply capacitor,
>I guess that 4KV from the HV transformer dont count, huh......
Although zapper is apparently much wiser than all of us, wouldn't
cutting the cable of the microwave be enough?
--
Kent Vander Velden
gra...@iastate.edu
Sam Goldwasser
> Although zapper is apparently much wiser than all of us, wouldn't
> cutting the cable of the microwave be enough?
He clearly knows that even if the transformer has been removed and disconnected
from the wiring, the kid will know where to locate a patch cord and plug,
connect it directly to the AC line, and then be stupid enough lick the output
terminal.
--- sam
Kennedy
>In <53epk4$o...@news.mhv.net> z...@mhv.net (zapper) writes:
>
>
>>>>Subject: Re: Safe to disassemble a microwave oven?
>
Just bad - gets to juggle with the kitchen knives.
Very bad - gets to play hide and seek on the freeway.
Really bad - gets to disassemble the microwave.
Sorry, I thought this thread was in alt.tasteless.jokes.
--
______________________________________________________
Kennedy
I was uncooled before uncooled was cool.
Richard M.
J. Zeigler wrote:
> You at best seem to have to engage in personal
> attacks and I'm not the only one you have done this with.
Hundreds read and post here. You fall into a category of a handful of
people who deserve comment on your persona. I make no apology for it.
> You don't
> reason, to always drop down to a personal attack.
"Always"... hmmm. Seems to be a biased and absolute statement. Please
don't confuse comment on your persona with argument ad hominem. It is
not the same. Do you know that?
>
> I notice that you still haven't responded as to your qualifications. Oh
> well, I didn't really expect you would anyway.
Then you don't read too well.
altavoz
Richard M. wrote:
>
> J. Zeigler wrote:
> > attacks and I'm not the only one you have done this with.
>
> people who deserve comment on your persona. I make no apology for it.
>
> > reason, to always drop down to a personal attack.
>
> don't confuse comment on your persona with argument ad hominem. It is
> not the same. Do you know that?
>
> >
> > well, I didn't really expect you would anyway.
>
do we need a nap little people ?
______End of text from altavoz___________
Richard M.
altavoz wrote:
>
> Richard M. wrote:
> >
> > J. Zeigler wrote:
> > > attacks and I'm not the only one you have done this with.
> >
> > people who deserve comment on your persona. I make no apology for it.
>
> do we need a nap little people ?
>
> ______End of text from altavoz___________
That actually made me laugh, AV. Thanks.
Jim Blaser
I would hate to get off of the subject of criticizing other peoples ideas
of safety, but is there any danger in taking the megatron apart to get at
those powerful magnets?
What exactly is inside of a megatron? I've seen the magnets, and the
aluminum heat sink surrounding it, but what is inside the megatron
itself?
This is assuming there is no power applied, and the capacitor is discharged.
BTW I'm an adult, and also aware of the dangers of RF energy.
Thanks in advance for a polite response,
Jim
Sam Goldwasser
In article <547vs2$s...@login.freenet.columbus.oh.us> jbl...@freenet.columbus.oh.us (Jim Blaser) writes:
> I would hate to get off of the subject of criticizing other peoples ideas
> of safety, but is there any danger in taking the megatron apart to get at
> those powerful magnets?
> What exactly is inside of a megatron? I've seen the magnets, and the
> aluminum heat sink surrounding it, but what is inside the megatron
> itself?
Absolutely no danger except to your credit cards and diskettes :-)
Disassemble the fins/steel case (usually unscrews), cut the filament
connections, and the magnets will come out. What you are left with is
the actual vacuum tube.
Inside is a filament similar to that in a light bulb and a set of circular
cavities machined/punched in the surrounding metal.
I doubt that there is any particular danger in breaking this open but some
have mentioned the possibility of toxic substances like berrylium. I don't
believe there is anything particularly dangerous inside but probably not
worth taking any chances.
You don't need to go inside to get at the magnets.
Get a copy of any good EE text and there will be a picture of a magnetron
construction.
BTW, it is a good idea to coat the magnets with a plastic based paint or
the stuff used to coat tool handles to prevent the brittle ceramic magnets
from chipping as the chips will manage to find their way everywhere and are
just as magnetic as the main ring.
--- sam