Strange Problem With Monitor being around Microwave..

[jason b]

Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living
room, theres a 'window' to the kitchen where I have my Microwave. They
are around 5' apart. When I turn my microwave on I get a noticable
shaking on my screen. It only has happpened with my new monitor ( Dell -
Sony Trinitron 19" model M991). Do I have anything to worry about as far
as ruining the display ?

tia ,

jason bean

--
((¯`'·.¸(¯`'·.((¯`'·.¸ * jason bean* ¸.·'´¯))¸.·'´¯)¸.·'´¯))

For me , said Sherlock Holmes, "there still remains the cocaine bottle,"
and he reached his hand up for it.

http://home.cogeco.ca/~jabean
http://musicpage.kicks-ass.org/

 

[Rubbishrat]

There's no real danger of doing any permanent damage to the screen, when you
move the monitor away from the powerful alternating magnetic field the
shaking should stop. Its just pulling the beams about inside the CRT. The
field is of course spherical in shape and its strength decreases in
proportion to the inverse of the square of the distance from the oven so
just another foot or so might be enough to stop the shivers. Try it!
Pete

 

[Ol' Duffer]

In my apt, I've got my monitor set up so that it's in my living
room, theres a 'window' to the kitchen where I have my Microwave. They
are around 5' apart. When I turn my microwave on I get a noticable
shaking on my screen. It only has happpened with my new monitor ( Dell -
Sony Trinitron 19" model M991). Do I have anything to worry about as far
as ruining the display ?

Your microwave generates a strong magnetic field (and to
a lesser degree your house wiring), which can deflect the
monitor's electron beam(s). Some monitors (and microwaves)
are better shielded than others. It won't do permanent
damage, but it can be a nuisance. It may be more or less
noticable on some display modes.

 

[Alan S]

On Sun, 20 Feb 2005 19:13:15 -0800, Jamie

|jason b wrote:
|> Does anyone know what would cause this to happen :
|> In my apt, I've got my monitor set up so that it's in my living room,
|> theres a 'window' to the kitchen where I have my Microwave. They are
|> around 5' apart. When I turn my microwave on I get a noticable shaking
|> on my screen. It only has happpened with my new monitor ( Dell - Sony
|> Trinitron 19" model M991). Do I have anything to worry about as far as
|> ruining the display ?
|>
|> tia ,
|>
|> jason bean
|>
| its most likely a voltage drop problem and i don't think its a good
|idea to operate your monitor that way. many things in your monitor are
|designed to operate at the correct voltage other wise, you may get
|area's in the monitor that will actually run hotter than it should due
|to improper voltages causing circuits to go off the lim..
| i would sugguest getting a UPS for your computer and Monitor.
|
It won't be voltage drop. Just EMI, maybe RFI. Just move them apart a
little more, or don't try to read the computer screen while cooking

I doubt that it's doing any damage; however, the screening on the
microwave is probably not much good. Hopefully nobody wears a
pacemaker in that house.

A new microwave would be far cheaper than an (unnecessary in this
case) UPS.


Cheers, Alan

 

[NSM]

Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living
room, theres a 'window' to the kitchen where I have my Microwave. They
are around 5' apart. When I turn my microwave on I get a noticable
shaking on my screen. It only has happpened with my new monitor ( Dell -
Sony Trinitron 19" model M991). Do I have anything to worry about as far
as ruining the display ?

It's normal. Move them further apart.

N

 

[Jamie]

Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living room,
theres a 'window' to the kitchen where I have my Microwave. They are
around 5' apart. When I turn my microwave on I get a noticable shaking
on my screen. It only has happpened with my new monitor ( Dell - Sony
Trinitron 19" model M991). Do I have anything to worry about as far as
ruining the display ?

tia ,

jason bean

its most likely a voltage drop problem and i don't think its a good
idea to operate your monitor that way. many things in your monitor are
designed to operate at the correct voltage other wise, you may get
area's in the monitor that will actually run hotter than it should due
to improper voltages causing circuits to go off the lim..
i would sugguest getting a UPS for your computer and Monitor.

 

[Jerry G.]

The magnetic field from the microwave, and possibly to a smaller degree, the
electrical wiring near the microwave that is supplying it, is creating a
magnetic field that the particular monitor is sensitive to. This will not
have a permanent effect on the monitor, but would be annoying to someone
like me.

If you move them a few more feet apart, you will see the effect decrease.

If you were to have an LCD type screen, there would be no effect from
magnetic fields, unless they were excessively strong.

--

Jerry G.
======



Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living
room, theres a 'window' to the kitchen where I have my Microwave. They
are around 5' apart. When I turn my microwave on I get a noticable
shaking on my screen. It only has happpened with my new monitor ( Dell -
Sony Trinitron 19" model M991). Do I have anything to worry about as far
as ruining the display ?

tia ,

jason bean

--
((¯`'·.¸(¯`'·.((¯`'·.¸ * jason bean* ¸.·'´¯))¸.·'´¯)¸.·'´¯))

For me , said Sherlock Holmes, "there still remains the cocaine bottle,"
and he reached his hand up for it.

http://home.cogeco.ca/~jabean
http://musicpage.kicks-ass.org/

 

[Jerry G.]

If the supply voltage was reduced to a CRT type monitor, the image size
would start to decrease, and the picture may have some blooming with the
increase of brightness. What is being described here, is the common effect
of a strong magnetic field to the mask and the deflection system of a CRT.

--

Jerry G.
======

Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living room,
theres a 'window' to the kitchen where I have my Microwave. They are
around 5' apart. When I turn my microwave on I get a noticable shaking
on my screen. It only has happpened with my new monitor ( Dell - Sony
Trinitron 19" model M991). Do I have anything to worry about as far as
ruining the display ?

tia ,

jason bean

its most likely a voltage drop problem and i don't think its a good
idea to operate your monitor that way. many things in your monitor are
designed to operate at the correct voltage other wise, you may get
area's in the monitor that will actually run hotter than it should due
to improper voltages causing circuits to go off the lim..
i would sugguest getting a UPS for your computer and Monitor.

 

[Sam Goldwasser]

its most likely a voltage drop problem and i don't think its a good
idea to operate your monitor that way. many things in your monitor are
designed to operate at the correct voltage other wise, you may get
area's in the monitor that will actually run hotter than it should due
to improper voltages causing circuits to go off the lim..
i would sugguest getting a UPS for your computer and Monitor.

More likely a magnetic interference problem from the large power transformer
in the microwave.

It isn't harmful except to your sanity.

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contact me via the Feedback Form in the FAQs.

 

[Jamie]

There's no real danger of doing any permanent damage to the screen, when you
move the monitor away from the powerful alternating magnetic field the
shaking should stop. Its just pulling the beams about inside the CRT. The
field is of course spherical in shape and its strength decreases in
proportion to the inverse of the square of the distance from the oven so
just another foot or so might be enough to stop the shivers. Try it!
Pete

5 feet away?

 

[Jim Adney]

Your microwave generates a strong magnetic field

The only thing in the microwave that would generate a strong AC
magnetic field would be the HV transformer. I've no direct experience
with microwave transformers, but I have a hard time imagining that
they are made so poorly that they have significant fringing magnetic
field that far away.

Are they really this poor?

Or is it more likely to be power line interference?

-

 

[NSM]

Or is it more likely to be power line interference?

But from where? The rectifier?

N

 

[Jamie]

If the supply voltage was reduced to a CRT type monitor, the image size
would start to decrease, and the picture may have some blooming with the
increase of brightness. What is being described here, is the common effect
of a strong magnetic field to the mask and the deflection system of a CRT.

to put an example as to why i say voltage drop is from experience.
i am not saying that is the problem how ever, i have had monitors and
Tv's produce that same effect due to the unit on the same line that
wasn't able to maintain the voltage to a minimum required level for the
regulator and thus caused strange bending and waving effects in the
image.
if this is the case, in some designs these effects are not healthy.

that is all i have to say about that one. i just find it hard to
believe that 5 feet of space is generating that kind of field, i think
i would have second thoughts about where i would be sitting on a
regular bases when the nuker was running.

 

[Tomi Holger Engdahl]

Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living
room, theres a 'window' to the kitchen where I have my Microwave. They
are around 5' apart. When I turn my microwave on I get a noticable
shaking on my screen. It only has happpened with my new monitor ( Dell
-
Sony Trinitron 19" model M991). Do I have anything to worry about as
far as ruining the display ?

The shaking on the screen could be either caused by the magnetic field
caused by the microwave oven (they have large transformers in them) or
because of the effect that microwave oven causes to your electrical
distribution (microwave oven takes lots of power, can cause noticeable
voltage drop on poor wiring etc..). Then there is possiblity of some
RFI getting to monitor because of some microwave leakage in your microwave
oven...

I don't think you need to worry bout ruining your display much...

 

[jason b]

On Sun, 20 Feb 2005 19:13:15 -0800, Jamie

|jason b wrote:
|> Does anyone know what would cause this to happen :
|> In my apt, I've got my monitor set up so that it's in my living room,
|> theres a 'window' to the kitchen where I have my Microwave. They are
|> around 5' apart. When I turn my microwave on I get a noticable shaking
|> on my screen. It only has happpened with my new monitor ( Dell - Sony
|> Trinitron 19" model M991). Do I have anything to worry about as far as
|> ruining the display ?
|>
|> tia ,
|>
|> jason bean
|>
| its most likely a voltage drop problem and i don't think its a good
|idea to operate your monitor that way. many things in your monitor are
|designed to operate at the correct voltage other wise, you may get
|area's in the monitor that will actually run hotter than it should due
|to improper voltages causing circuits to go off the lim..
| i would sugguest getting a UPS for your computer and Monitor.
|
It won't be voltage drop. Just EMI, maybe RFI. Just move them apart a
little more, or don't try to read the computer screen while cooking

I doubt that it's doing any damage; however, the screening on the
microwave is probably not much good. Hopefully nobody wears a
pacemaker in that house.

A new microwave would be far cheaper than an (unnecessary in this
case) UPS.


Cheers, Alan

It's a small micorwave. Panasonic I think. Sooner or later it'll get
replaced.


jason



--
((¯`'·.¸(¯`'·.((¯`'·.¸ * jason bean* ¸.·'´¯))¸.·'´¯)¸.·'´¯))

For me , said Sherlock Holmes, "there still remains the cocaine bottle,"
and he reached his hand up for it.

http://home.cogeco.ca/~jabean
http://musicpage.kicks-ass.org/

 

[jason b]

There's no real danger of doing any permanent damage to the screen, when you
move the monitor away from the powerful alternating magnetic field the
shaking should stop. Its just pulling the beams about inside the CRT. The
field is of course spherical in shape and its strength decreases in
proportion to the inverse of the square of the distance from the oven so
just another foot or so might be enough to stop the shivers. Try it!
Pete

I tried this Pete and it seems to be the problem. I moved it towards
the screen and it got worse and visa versa. Thanks alot for the help.

j b



--
((¯`'·.¸(¯`'·.((¯`'·.¸ * jason bean* ¸.·'´¯))¸.·'´¯)¸.·'´¯))

For me , said Sherlock Holmes, "there still remains the cocaine bottle,"
and he reached his hand up for it.

http://home.cogeco.ca/~jabean
http://musicpage.kicks-ass.org/

 

[Boris Mohar]

Does anyone know what would cause this to happen :
In my apt, I've got my monitor set up so that it's in my living
room, theres a 'window' to the kitchen where I have my Microwave. They
are around 5' apart. When I turn my microwave on I get a noticable
shaking on my screen. It only has happpened with my new monitor ( Dell -
Sony Trinitron 19" model M991). Do I have anything to worry about as far
as ruining the display ?

You won't ruin the monitor. If it really bugs you get an LCD monitor.



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

 

[Asimov]

"Jerry G." bravely wrote to "All" (20 Feb 05 22:20:24)
--- on the heady topic of "Re: Strange Problem With Monitor being around
Microwave.."


It could simply be the MWO triac leaving notches in the power line ac
and this harmonic rich waveform is modulating the monitor's supply.
IOW the monitor's line regulation is rather poor. Try it on a
different breaker circuit, that might clear up the problem. I can't
believe the magnetic leakage from the MWO transformer is that great.
However the shielding on many monitors is scant to non-existant so it
wouldn't be too surprising.


JG> From: "Jerry G." <[email protected]>
JG> Xref: aeinews sci.electronics.repair:11081 sci.electronics.misc:3798

JG> The magnetic field from the microwave, and possibly to a smaller
JG> degree, the electrical wiring near the microwave that is supplying it,
JG> is creating a magnetic field that the particular monitor is sensitive
JG> to. This will not have a permanent effect on the monitor, but would be
JG> annoying to someone like me.

JG> If you move them a few more feet apart, you will see the effect
JG> decrease.
JG> If you were to have an LCD type screen, there would be no effect from
JG> magnetic fields, unless they were excessively strong.

JG> --

JG> Jerry G.
JG> ======


JG>
JG> Does anyone know what would cause this to happen :
JG> In my apt, I've got my monitor set up so that it's in my living
JG> room, theres a 'window' to the kitchen where I have my Microwave. They
JG> are around 5' apart. When I turn my microwave on I get a noticable
JG> shaking on my screen. It only has happpened with my new monitor ( Dell
JG> - Sony Trinitron 19" model M991). Do I have anything to worry about as
JG> far as ruining the display ?

JG> tia ,

JG> jason bean

.... High Voltage Electronics: Life's a glitch, then you fry.

 

[Bob Myers]

The only thing in the microwave that would generate a strong AC
magnetic field would be the HV transformer

Not so; you're forgetting the AC power line itself, which
obviously is carrying a fairly high current wheneve the
microwave is operating. And said power line includes
that bit in the wall, which could be directly behind the
monitor in question.

From the description, this is almost certainly a magnetic
interference problem.

Bob M.

 

[Jim Adney]

But from where? The rectifier?

Yes, that's always been my assumption. (Or rather that there's
distortion of the AC line waveform where the rectifier conduction
turns on and off.) My TV gets "hum bars" on it whenever the microwave
is on. The bars are clearly tied to the line frequency. I see 2 "hum
bars" per TV frame, so I believe that this indicates 120 Hz. A full
wave rectifier would produce a 120 Hz pattern, while a magnetic flux
problem would be 60 Hz.

My TV is 15' from the microwave, so I really don't think that it's the
leakage flux from the transformer.

-