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/

"Jamie" wrote in message
...
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


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

In article ,
says...
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.

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

|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

"jason b" wrote in message
...

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

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.

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.
======


"jason b" wrote in message
...

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/

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.
======


"Jamie" wrote in message
...
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.

Jamie writes:

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.

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

It isn't harmful except to your sanity.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

Rubbishrat wrote:

"Jamie" wrote in message
...

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



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?

On Sun, 20 Feb 2005 19:37:28 -0500 Ol' Duffer
wrote:

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?

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

"Jim Adney" wrote in message
...

Or is it more likely to be power line interference?

But from where? The rectifier?

N

Jerry G. wrote:

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.

jason b writes:

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...

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

On Sun, 20 Feb 2005 18:22:00 -0500, 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 ?

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

"Jerry G." bravely wrote to "All" (20 Feb 05 22:20:24)
--- on the heady topic of " 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."
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 "jason b" wrote in message
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.

"Jim Adney" wrote in message
...
On Sun, 20 Feb 2005 19:37:28 -0500 Ol' Duffer
wrote:

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

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.

On Mon, 21 Feb 2005 07:04:29 GMT "NSM" wrote:

"Jim Adney" wrote in message
.. .

Or is it more likely to be power line interference?

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.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Monday, 21 Feb 2005 10:58:46 -500, "Asimov"
wrote:

"Jerry G." bravely wrote to "All" (20 Feb 05 22:20:24)
--- on the heady topic of " 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."
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 "jason b" wrote in message
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.

I have the same problem with mine. Every time the microwave is turned
on I get slight blurring and jitters.
The monitor is in my office opposite the kitchen.(micro is on the
other side of the wall.)
Been doing this for years and hasn't harmed my monitor in any way yet.

On Mon, 21 Feb 2005 19:04:26 -0700 "Bob Myers"
wrote:


"Jim Adney" wrote in message
.. .
On Sun, 20 Feb 2005 19:37:28 -0500 Ol' Duffer
wrote:

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

Not so; you're forgetting the AC power line itself, which
obviously is carrying a fairly high current wheneve the
microwave is operating.

That's true, and I hadn't thought of that, but the amount of magnetic
field it would create really just depends on the amount of area inside
the current loop. Assuming that this is wired in the usual way, that
loop is pretty small, since the two conductors are parallel to each
other and maybe just 1/4" apart.

I don't think that would do it, but if there was some sort of wierd
(and possibly illegal) wiring scheme that created a current loop that
surrounded the room, then that would certainly cause such a problem.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

"Jim Adney" wrote in message
...
Not so; you're forgetting the AC power line itself, which
obviously is carrying a fairly high current wheneve the
microwave is operating.

That's true, and I hadn't thought of that, but the amount of magnetic
field it would create really just depends on the amount of area inside
the current loop. Assuming that this is wired in the usual way, that
loop is pretty small, since the two conductors are parallel to each
other and maybe just 1/4" apart.

Yes, you'd think it was pretty small - but this happens all the
time. It just doesn't take that much field to affect the typical
CRT display. (I've seen AC fields all the way down to 0.1 Gauss
or a bit less still result in visible movement on the screen, during
mag. susceptibility testing - and just to put that in context, that's
something like a fifth of the strength of the Earth's field typical
in North America.) The problem is that it's an alternating
field; low-level DC fields simply cause a static displacement,
which you'll either ignore or adjust out with the centering controls,
but an AC field results in a very annoying jitter.

Bob M.

"NSM" wrote in message news:4MaSd.6667$9a3.1052@edtnps91...

It's normal. Move them further apart.

Plugged into same or adjacent AC circuit?
Doubt if it is Microwave RF field; they are not supposed to leak that much
if properly buttoned up even though there is several hundred watts of
microwave RF floating around inside to cook/heat the food.
So that means interference either magnetic field and/or distortion of the AC
waveform due to the m.wave transformer saturating each half cycle (120 times
a second?). Read somewhere that those m.wave mains transformers which feed
voltage doubling rectifier circuits for up to 5 to 6 Kv Dc for the magnetron
do operate into saturation, waveform not being important.

Hopefully nobody wears a
pacemaker in that house.

Excellent point:
Sometimes see notices in restaurants and lunch rooms where 'customers' may
microwave food themselves
"Microwave in use"; as a warning to pacemaker users! Also at an airport
lunch counter where microwave was in use by serving staff.

"Terry" wrote in message
.. .

Hopefully nobody wears a pacemaker in that house.

Excellent point:
Sometimes see notices in restaurants and lunch rooms where 'customers' may
microwave food themselves
"Microwave in use"; as a warning to pacemaker users! Also at an airport
lunch counter where microwave was in use by serving staff.

I've never believed that was more than a stupid warning, i.e. rubber ducky
marked "Not a Flotation Device"!

N

NSM wrote:

"Terry" wrote in message
.. .

Hopefully nobody wears a pacemaker in that house.

Excellent point:
Sometimes see notices in restaurants and lunch rooms where 'customers' may
microwave food themselves
"Microwave in use"; as a warning to pacemaker users! Also at an airport
lunch counter where microwave was in use by serving staff.

The warning is in case the door seal becomes defective. The leaking
high power RF can cause erratic operation or total failure of the
electronics in their pacemaker. Microwave ovens in commercial settings
get a lot of use so the chances of a failed seal are much higher.

I've never believed that was more than a stupid warning, i.e. rubber ducky
marked "Not a Flotation Device"!

N

That's exactly who the warning is for, "The stupid!" On the other
hand, if you cant swim, anything that floats may improve your chances of
keeping your head above water for a few more minutes but the toy maker
doesn't want to be sued if you drown anyway.

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida