Subject:  Re Request for information on PC Laptop with low EMFs (fwd)
Date:     Wed, 13 May 1998 141827 -0500 (CDT)
From:     "Roy L. Beavers" <rbeavers@llion.org>
To:       emfguru@hotmail.com
--------------------------------------------------



---------- Forwarded message ----------
Date: Wed, 13 May 1998 08:44:27
From: Alasdair Philips 
To: "Roy L. Beavers" , emfguru@hotmail.com
Cc: Pamela Schreiner 
Subject: Re: Request for information on PC Laptop with low EMFs (fwd)

Most modern lap-tops give off negligible EMFs (1000's of times less than
even the best desk-top VDU units) BUT....
Most, when run from their mains-adapters/re-chargers float up to half the
supply voltage (i.e. about 60vAC in your case, 120vAC in most of Europe)
which causes the keyboards to give off VERY high EMFs of several hundreds
of volts per metre.

The cure is easy ~ you need an earth wire from the computer (usually connect
at one of the port connectors on the rear) to a local safety electrical
earth line (usually available at the mains plug).  The reason for this
problem is that most laptop psu's only have a two wire connection to the
mains and therefore "float" (it is called "double insulated") ~ which is
a real problem for ES and can also cause/aggravate RSI as the fingers are
in these high electric fields.

I have not found the use of a screen helps reduce EMFs in laptops if the
above "earthing" is done, and they increase eye strain as the displays 
are never super-bright to start with.

Alasdair Philips,
EMF Consultant, UK.
============================================================

At 15:31 12/05/98 -0500, Roy L. Beavers wrote:
>
>---------- Forwarded message ----------
>Date: 12 May 1998 15:13 EDT
>From: Pamela Schreiner 
>To: rbeavers@llion.org
>Subject: Request for information on PC Laptop with low EMFs
>
>Could someone advise me which PC laptop has the lowest EMFs? And which
>grounded shield for monitors would reduce EMFs the most?
>
>I have electromagnetic sensitivities and am still working with computers 
>on a daily basis. We're now changing from MACs to PCs and I believe I
>have the opportunity to specify the equipment I get. I believe a laptop
>would be best. I would also need a good shield for the screen -- from
>the little testing I've done, I observe that some of the shields only
>reduce emissions by about half. 
>
>Thanks
>
>Pamela Schreiner
>pamela@nortel.ca
>
>
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips    (aphilips@gn.apc.org)
Director, UK Powerwatch,
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



Archive provided courtesy of WaveGuide, http://www.wave-guide.org
Reprinted with permission of Roy Beavers, http://www.feb.se/EMF-L/EMF-L.html