Computers for the Electrically Sensitive (ES)

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Computers

 

for the Electrically Sensitive (ES)

by an ES Engineer _http://www.ctaz.com/~bhima/emfcomp.htm_

(http://www.ctaz.com/~bhima/emfcomp.htm)

 

EMF Control for Computers

Computer Tips

Gathering Stories

Questions and Answers

Proper Use of a Trifield Meter

Building a computer from scratch

EMF from hard drive

EMF from mouse

Modifying Keyboards and Screens

ES or Flicker Sensitive?

 

__

EMF Control for Computers

Build Your Own Computer Box. Professionally designed and excellent source for

extreme EMF sensitivity. Arizona Technology Access Program (AzTAP).

Information and photos for low emission computers of the electro magnetic

field.

_http://www.asilo.com/aztap1_ (http://www.asilo.com/aztap1/)

Computer Tips

Most will do better with a laptop or LCD display, unless you are very 60 hz

flicker sensitive. That eliminates most of the low frequency magnetic field,

which is very costly and hard to shield. The cords all need to be wrapped in

aluminum foil, too.

 

ES, is like allergy, only the substance is different frequencies of electro

magnetic fields. If someone is more sensitive to the low frequency magnetic

fields of a conventional monitor, then a switch to LCD might help. Likewise,

the emissions from a laptop will generally be lower, overall. However, I do

recommend that an external keyboard and mouse be used, and the unit kept away

another 18 inches.

Some will tolerate a conventional desktop computer better. If so, count

your blessings and buy a KVM extension (keyboard, video, mouse), get the

computer in another room and add a good power line filter before it plugs in.

Many

with MCS/ES have vision and hearing problems, and so faster CRT type monitors

may work better for them.

There are no practical tests other than trying different types of equipment

to see what is tolerated. [Editor's note: Have patience for the one

undergoing these tests, because the ES person can go through hell.] For any ES

that

cannot tolerate either a monitor or fluorescent backlit LCD, a plasma display,

or making an incandescent (conventional light bulb) back lit LCD display,

might be a solution.

Gathering Stories

 

_MCS Acquires Electrical Sensitivity (ES) _

(http://www.ctaz.com/~bhima/eskemp.htm)

 

 

Mary Kempf. MCS of 18 years, acquires a new sensitivity. Expertise and

commentary by an ES engineer.

 

 

Questions and Answers

Proper Use of a Trifield Meter

 

Q Do you have suggestions for someone using the Trifield meter to measure

output on computers. My neighbor friend, took one to a computer store to

measure an LCD monitor. She does not have EMF, her husband does. She tried to

measure it at home also, and the readings were as high as her CRT monitor. Her

monitor was only 2 feet from the computer. It seems like it should be measured

a

certain distance away from another component. What would that distance be?

A The Trifield meter has a responce curve that is only calibrated at 60 Hz.

I believe it peaks at 10K hz and then falls to just 1% at 100K hz. So the

readings one may get don't necessarily tell the whole story. However, a

commercial lcd display will have inverters located on the lcd controller for

it's own

use and for and the flourescent backlight. These inverters are now often in

the range of 100K to 500KHz in frequency. In the 500 KHz range, you would

expect to see harmonics to 50 MHz. So yes, many folks will find LCD displays

bothersome EMF wise as well as 60 Hz flicker-wise, and sometimes with magnetic

field readings over what a conventional CRT monitor generates. Given that the

Trifield is reading less than 1% of the actual values for these inverters,

you can see that the emissions can be substantial. In general, inverters are

our enemy. It is getting increasingly hard to find products that don't use

them, even in simple battery powered devices. It is possible to disable them

and

add external linear power supplies; this is what I did with the Eagle Vision

lcd controller. It's very high digital emissions were still more that my

projector shielding could handle.

Yes, It's also possible that your friend was reading the magnetic field from

the computer instead of the display. The units should be separated at least

6 feet for such measurements.

Building a computer from scratch

Q I have been very impressed with your low emission computer works, and I

have a disability grant of about $6000 AU (about 3500 USD) to get low emission

hardware for my electrosensitivity. I was wondering what you thought of the

following solution: monitor: BEMI Sweden makes a special LCD panel: little mag

field via circuit reorganisation and shielding, no fluoros (some

incandescent setup), low elec field via shielding, vacuum sealed enclosure to

contain

circuit board VOC offgassing (about 4000 AUD) keyboard: I am obtaining a

TEMPEST military one. mouse: bit of a problem, will work something out. CPU box

enclosure: bit of a problem. Thought I may use a thick silicon steel rough

enclosure with penetrations for cabling, made by a contractor, and remoted

about 5

metres from screen. (It needs to be a bit portable) I am told that if I cut

the mag field at the source, it will in turn diminish elec emissions.

Alternatively, I can have an aluminium box built for elec shielding, but

securing

the cable exits is costly and difficult. I am concerned that if I use the steel

mag shielded box, I will have problems with conducting cables leaving the

box, effectively diminishing the shielding quality of the monitor/ keyboard.

Power Source: thought I might rely on the silicon steel to shield the switch

mode in the PC, alternatively, I have been advised to run a laptop off a car

battery to remove conducted transients from the power line.

I am most concerned about the shielding of the LCD being significantly

diminished if it is grounded straight to the PC box, which may mean I am

wasting

much money there. As you say, I need to obatin 60- 80 dB, and I will use it

about15 hrs / week occupationally, I will run a business later with an internet

shop front. Also: www.mcsrelief.com people claim very good results for their

electrosensitives by using a minimally shielded 'fume hood' for computers to

suck away the VOCs. I can very easily make one of these, and was wondering

whether you had any knowledge of their effectiveness.

A I'm very impressed with your questions. You've obviously done some good

research. Here's some thoughts, not very organized, for your to consider: The

BEMI LCD unit sounds very good, but I have not evaluated one. LCD displays are

sometimes problematic; the commercially available displays are all refreshed

at 60hz, regardless of input frequency. While the depth of modulation

(flicker) is very small (<=1% rms), I've found that lots of folks with MCS/ES

are

very, very, 60 Hz flicker sensitive. So first evaluating any active matrix LCD

display visually would be an important step. I recently checked out a custom

LCD controller by Eagle Vision that was modified to push the timing specs to

85 hz refresh rate. I modified the board to eliminate on board inverters,

which are a big emission source. It worked, and the display was much better

tolerated by me, but the high frequency emissions of the board were too great

for my custom shielded projector enclosure. (It uses the now obsolete Sharp

LQ64SP1, 6.25 " projection panel.) It is very difficult to have over 100db of

shielding effectiveness for 1Ghz and above. Someday I hope to develop a custom

fiber optic LCD interface which would allow me to drive the LCD at 85 hz but

not have a high emission controller like the Eagle Vision Flight Board in the

projector. For now, I have to take a break from electronics work. It is very

destructive to my health.

Some very flicker senstive folks have done better with high refresh rate

(>=100 Hz) conventional montiors. For me that's not practical due to the

shielding limitations. (A large open ended mu-metal enclosure limits shielding

reductions to 75% or less towards the front.)

Yes, high frequency emissions from the cables would effectively eliminate

your shielding effectiveness. For my rear projection setup, I got around the

problem by developing a fiber optic video, keyboard, and mouse interface. For

the setup you're talking about, military grade power filters would be used

between the power line and the computer. They generate low frequency magnetic

fields, however. I think it's best to remote the computer, so that only modest

shielding is used. Use rigid conduit (not the thinwall EMT) to connect a KVM

extender to your workstation (preferably the old fashioned analog type), and

I have developed a method to break the ground loop (and low frequency

magnetic fields) which can occur from this approach. Then low impedence earth

connections can be made without generating magnetic fields. This method was

used on

the secure room - shielded projection room which I designed in the

(http://www.asilo.com/) _http://www.asilo.com/aztap1_

(http://www.asilo.com/aztap1/)

Low frequency emissions were less than 0.002 milligaus throughout the living

areas of the house.

I was not able to tolerate a tempest keyboard. I hope that will be good

enough for you. You can achieve tempest levels yourself by shielding with foil

and copper tape the inexpensive keytronic brand keyboards. Foil can be wrapped

around the entire keyswitch membrane. The tempest unit I tried had large

openings at each key, and copper wrapped processor. I ended up spending over a

year researching and developing a method to eliminate the processor and the

actively strobed keyboard key matrix. It was more difficult that the rest of

the

system combined in time and effort. The problem is the keyboard is in your

lap, and by some means must connect to the computer. My passive matrix

keyboard with optical and fiber optic interface to the computer works great,

even

for someone like me who is adversely affected by a solar powered calculator.

Alas, this is not available in circuit board, and the processor board which was

modified for this use from an old IR keyboard/trackball made by Keytronic is

no longer in production. I used a similar approach for the trackball; no

processor at the track ball, and optical isolation from the processor, and

fiber

optic isolation from the remote computer. A conventional keyboard's cable

connecting to the computer is of course a big antenna. If you use a direct

connection, you'll have to use rigid conduit to the computer, using a

sleeved-capacitive joint (I'll tell you how to make one) to break the ground

path for

60hz. At the workstation end, you'll have to provide a <2 ohm gound path via

000 welding cable or better, and go from conduit to 2 or more layers of copper

braid the last couple feet or so to the keyboard shield enclosure. (The

copper foil around the processor in either a Tempest keyboard or your own make

from a Keytronics.) If you use a KVM extender (analog), it should be in a

shielded enclosure 6 feet from the keyboard, with rigid conduit entering and

exiting. It's power should come from the computer end. Signal ground should be

totally isolated from the shield ground of the rigid conduit and keyboard

shielding. If you use a KVM extender and pipe (rigid conduit here in the US),

you

should pick a mouse/trackball with spoked wheel interupter. (Old fashioned.)

Then you can buy two, and rip the processor out of one. Then provide power to

light the IR LEDs (4), and send the photo transistor outputs (4) and

left/right switches (2) back to the processor in the other good board, through

an

opto-isolator.

If a conventional trackball doesn't bother you too badly, you may be able to

use copper foil to improve it, but don't expect more than a modest

improvement; you should be able to tolerate it fairly well with no shielding or

don't

bother with that approach.

Fume hoods are very helpful for chemical problems, but are useless for EMF

problems or flicker problems. Also, I've found that many MCS/ES people are

extremely sound sensitive, and the hum of fans and some motor noises are

debilitating to them. So always first evaluate the sound problem. In the

Montana

setup, (http://www.asilo.com/) _http://www.asilo.com/aztap1_

(http://www.asilo.com/aztap1/) the remote cooling blower located in her attic

was found to be a

big issue. I had to replace it with a lower rpm unit, suspend it with a

spring, and wrap it in 8 " of insulation. The old blower was just barely

audible,

but it was a frequency and character of noise that affected her severely. I

only found it out by single blind testing her, turning off various pieces of

equipment until I found that they were all off but the fan! For my own

projection system, I use a single cooling blower carefully selected for low

noise

and rpm, located in the attic, isolation mounted on 6 " of foam and again

blanketed with insulation. Thus the cooling air ducting for the projector makes

it

look like something military from the 50's. The projector is a sealed shield

enclousure with honeycomb shield vents on air inputs and outputs. Power is

filtered at entry to the projector, and data signals are all fiber optic. The

unit turns itself on by air switch when the cooling fan is operating.

Each individual has their own spectrum plot of susceptability; different

specific ranges of frequencies will elicit a bad responce. The more EMF

sensitives have fewer and smaller ranges of frequencies which are not not

bothersome.

In some cases, just by trying a bunch of different pieces of equipment, one

can find a unit which is by chance a better match of it's emissions to your

own sensitivities. Starting by evaluatng the keyboard and display (visual)

issues seems a good place to start. I know a lady with a 3M 6400 VGA projection

panel who would like to sell it; I think she just wants $150. This with an

incandescent spot lamp and drafting vellum for diffuser would allow you to

evaluate that cheaply. It did not work for her; she is too flicker senstive and

can only use an old passive matrix monochrome LCD. (Which allows her to do the

word processing she needs as a professional writer, but not the internet and

email access she badly needs.)

EMF from hard drive

Q Certain electrical devices bother my uncle. He has a PC that didn't bother

him until I put a new hard drive in it; now it makes his joints hurt. One

solution might be to separate the computers from him physically and set up a

monitor/keyboard/mouse via cables and maybe a signal booster. I talked to a man

at a computer store who told me he did that for someone. Can you help or

direct me toward some help in this area?

A Since your uncle is still only somewhat EMF sensitive, there's a good

chance we could come up with a practical solution for him. The new drive may

have

had a more powerful stepper motor for head positioning, worse radio

frequency emissions from it's circuit board or cable, etc. Not a great sign for

him

that such a small change in EMI caused a problem, but a very common scenario.

Yes, remoting the keyboard and display is generally a good strategy. The

best bet is for him to try a bunch of different displays to see if he can find

one whose emissions are not in problematic frequencies. Imagine a spectograph

of the emissions of the display, and another spectograph which might

represent youe uncle's susceptability to the same broad range of frequencies.

By

trial and error, we're trying to find a good match between these two. Even

though

the essential technology is identical, the differences felt by someone

electrically sensitive can be profound.

But if he needs his laptop portablility, you could also look at other

laptops. Macs are generally the lowest in emissions, since even their US models

meet European emission standards, which are tougher than ours. You might also

consider just replacing the disk drive again- check the make, model and

performance specs on both the old and new drives, perhaps and alternate with a

better chance of being " OK " may be found.

Another strategy that has consistantly been helpful is to lower his overall

daily EMF exposure, especially at rest and sleep. Usually, if a problem is

found in the home environment, a significant (tenfold or more) improvement of

this will result in a significant improvement in about 3 weeks.

This requires getting a magnetic field meter and checking those areas, and

making adjustments such as moving clock radios from the head of the bed, etc.

The only commercial meter I recommend is the standard Trifield Meter with

custom 100x external probe, available from Dr. Lee of AlphaLabs, Salt Lake

City,

Utah. 800-769-3754 Tell Dr. Lee I sent you. The standard meter is modified

to add a jack on the side so that the 100x external probe can be plugged in

when higher sensitivity is needed.

Reducing his daily exposure level soon is the best insurance for his long

term health and success. What he learns in doing so may make a big difference

in avoiding bad situations in the future, as well. If only I had known ...

EMF from mouse

Q Do you know of any way to shield my hand from the electricity emitted by a

computer's mouse? My right hand " fries " and " prickles " with contact. It is

aggravating (or precipitating?) and arthritic condition. I have tried a radio

signal mouse, but this seems worse than the ball-rotating type. I hope there

is some advice other than having to give up computer contact altogether.

A The microprocessor, clock and synchronous serial data cable to the mouse

are problematic for lots of folks, including myself. There are two possible

solutions to the mouse problem: First is to shield the mouse internally by

using aluminum foil around the circuit board. To see if this is going to be

sufficient, try wrapping the entire mouse and a bit of the cord with foil (it

won't work then), covering it with a piece of cloth so you aren't touching

foil,

and sit there and see if it feels much better. Also try foiling the entire

cord and attaching the foil to an earth ground if the prior attempt is

unsuccessful. If either of these approaches work, take the bugger apart and

foil it

internally, and put braid over the cord if needed. I could provide a more

detailed explanation of what this does and doesn't shield, but I don't know

that

it would be helpful for the layperson.

If foiled shielding is inadequate, then it's a engineering job. In my track

ball, I disabled the microprocessor and all the circuitry except the LEDs and

photodetectors, and then use opto-isolators between the photodetector (4)

signals and a the microprocessor from a second track ball. A separate clean

regulated power supply (very small toroidal transformer remoted) is used power

the LEDs and photodetectors. I am unable to build these for someone but will

be glad to provide technical consulting for an engineer or good electronics

technician who is willing to do the work for someone.

Modifying Keyboards and Screens

This approached worked for a mildly EMF sensitive person, though it is not

recommended for the extremely EMF sensitive.

 

Q My approach was to take the info on the site, combine it with my symptoms,

and try to find inexpensive solutions using off the shelf technology. If

this hadn't worked I would have looked at the more bespoke solutions but that

turned out not be necessary. Before I started this exercise I was using a

earthed laptop, with and external keyboard and mouse, but found after 30

minutes

in front of the lcd, I was getting a feeling of sun burn. Even ignoring the

screen effects, I was getting headaches if I just rested my hands on the

keyboard. So extrapolating from what I had seen on the site, I needed an lcd or

similar rear illuminated projector. Airgap between keyboard and computer - an

IR

keyboard.

I agree in part with the comment on DLP projectors (see answer below) and

colour wheel effects. I sometimes notice the effect if I watch a film with this

projector when there are large areas of the image changing quickly, but on a

computer display I haven't noticed it. I think it would be worthwhile

putting together various hardware configs which have been useful to people

together

with the sensitivity level they address. I would have thought it would give

other ES people a place to start.

First for the keyboard: I found a couple that have Infrared connection with

the computer and are battery powered with 3 metres range. It looks like most

of these are being discontinued, but a Google search for " infrared keyboard

airkey " finds a selection. I saw some for less than UK£25. For a screen, I

read the advice a number of times, then guessed that one of the solutions that

would work was a data projector. Consequently I bought a benq PB6200, which

gives XGA for a UK£1020. Combining these allows me to use a computer over 2

metres away with no ill effects. I have also been careful about routes of power

and network/modem cables, so they stay well away from me.

A While I'm glad that he has a setup he can use, and this is a possible

approach for mildly ES, many would find either the IR keyboard or the projector

intolerable. Here's why: A modern LCD or DLP projector uses a switching power

supply both for the LCD/DLP controller board and (more importantly) the metal

halide lamp. The lamp generates substantial RFI, since it is an arc device

driven with a high current (AC) square wave. Very few ES types bad enough to

not tolerate a well chosen laptop (one which matches their personal

sensitivities fairly well) could be in the same house with a projector. Also

the DLP

projectors are usually not tolerated due to the color wheel and resulting

spectural flicker. Many " normal " people find the DLPs objectionable, visually.

IR

keyboards do eliminate the cable to the computer, but the microprocessor in

the keyboard is still a significant source, and the high current pulses to the

IR LEDs make them higher in emissions than most conventional keyboards.

There is no substitute for individual testing of components other than

extreme levels of shielding and isolation, which are usually not affordable. I

wish the problem was easier- but the most likely to be successful approach is

to

try a lot of different units to find ones which are more personally

compatible, and then do modest, affordable levels of shielding and use distance

(with

shielded cables) to reduce exposure levels in order to avoid sensitizing

over time.

ES or Flicker Sensitive?

Q I would like to know how to test if I have electrical sensitivity or

flicker sensitivity. I teach school all day under many fluorescent lights and

have

symptoms afterwards. I also have the symptoms after watching TV. My LCD

screen on my computer does not seem to bother me. How can I determine what my

sensitivity is?

A If she covers the TV display with paper and still gets her symptoms while

reading or lounging nearby while it is on, then it's ES. If she was really

flicker sensitive, the LCD display would be bothersome since it's a 60 Hz

display with a small amount, less than 1%, of modulation or " flicker. "