Posted by Garth Hitchens on
URL: https://www.es-forum.com/Marc-Arjuna-beware-laptops-too-also-blowdryers-tp1542893p1542939.html

Ok, to add one more opinion to the issue of Laptop computers.

In my experience, using a laptop, especially on your lap, could be
asking for trouble, depending on the design of the laptop.

One of the first devices that I found that I was electrically
sensitive to was a 17" Apple Powerbook G4 laptop. I would get
intense dizziness and tinnitus within minutes of using it, regardless
of whether it was plugged in or not. Using it on my lap
exacerbated the effect. Upon examining the magnetic field with a
spectrum analyzer, it put out a large amount of "repetitively pulsed
electronic noise" from directly below my left wrist near the keyboard
area.

I ultimately had to stop using it due to the symptoms.
Interestingly, another person with a 17" powerbook G4 mentioned to me
independently that they had symptoms when using the laptop (again,
off power). This model is no longer produced, having been replaced
by the Intel-based MacBook and MacBook pro line.

I have since extensively used an apple MacBook as well as a Macbook
Pro that LOOKS exactly like the Powerbook that gave me trouble, and
neither seems to cause me much trouble even when plugged in (all
computers bother me some). My spectrum analyzer still shows a fair
bit of noise, but at different frequencies and pulse rates.

from this I conclude that it is not just using a laptop or not, or
if it is plugged in or not, but that the internal design of the
laptop can also have a profound effect. Although it sounds odd, I
have found that at least for the Apple laptops, the switch from
motorola G4 to Intel's CPU seemed to change things enough that my ES
is not triggered anywhere nearly as much.

As Shivani has mentioned, the high frequency noise caused by internal
power conversion circuitry seems to be a key factor in ES issues.
While some of these are only active when the unit is powered by AC
power, most (like the flourescent display inverter, and dc/dc
inverters) are active anytime the laptop is in use, regardless of if
the unit is plugged in or not. And many of these are located just an
inch from your palms when you are using the laptop keyboard.

As a result, I find my ES symptoms are least triggered by using
either the laptop OR a desktop computer with standard (external)
keyboard and mouse to keep my body away from the internals of the
computer as much as possible.

Finally, I would mention that I have found it useful to keep the
actual power adapter unit for the laptop as far from my body as
possible when using a laptop "plugged in".

Hope that is useful for someone. Of course, your mileage may vary.

Garth

On Nov 27, 2006, at 7:26 AM, Marc Martin wrote:

>> He, in turn, said that many people gave him feedback that battery
>> operated laptops were NO good.
>
> Well, if Shivani says that it works for her, then that's good enough
> for me. It's a bit silly to believe some "expert opinion" over
> someone's
> first-hand experience.