Hello Andreas:
1) PCMCIA cards.
a. I have not heard of any safety problems IN PCMCIA
cards.
It is possible that a fault in the card could cause
an overheating event in the card. For an overheating
event to develop into a fire, the combination of the
card and the host computer would have to provide air
(oxygen) to the fuel for any fire to exist. Within
the PCMCIA card assembly, there is insufficent air to
allow a fire to develop. Even before a fire erupts,
the heating usually causes oxidation which will consume
any available oxygen in a small space. Therefore, the
heating event would have to be sufficiently great as to
cause heating of fuel materials in the host computer to
ignition temperatures. Ignition temperatures of plastics
range from 350 C to 475 C. It is unlikely that a fault
in the PCMCIA card can dissipate sufficient power to
heat a plastic in the host computer to ignition
temperature before the failure becomes so gross as to
open a component and interrupt the current.
You asked about safety problems CAUSED BY the PCMCIA
card. A safety problem caused by the card would
likely appear in the computer. Typically, this would
be an overheating situation somewhere in the computer
circuits that provide power to the PCMCIA card.
b. Warnings against other brand PCMCIA cards.
This may be a good idea from a safety point of view,
but severely limits the usefulness of the PCMCIA
capability.
The only hazard associated with PCMCIA cards is that
of fire. I've already mentioned that it is unlikely
that a PCMCIA card could itself burn. The host
computer slot can be constructed so as to prevent
spread of heating such as by using a metal enclosure
around the PCMCIA slot so as to act as a heat sink in
the event of an overheating event.
Further protection against overheating can be provided
by controlling the overcurrent to the PCMCIA card by
means of a fuse or a current-limiting regulator.
c. PCMCIA card manufacturers safety tests?
I don't know. But, I would doubt it. The amount of
testing is immense base on all the different notebook
and other PCMCIA card applications.
d. Safety tests with PCMCIA cards in place?
Yes and no.
Input tests would be done with all PCMCIA slots loaded
to maximum power. Same for the heating tests.
IEC 950 says that no abnormal fire tests are necessary
if the supply is "Limited Power" (as specified in Sub-
clause 2.11). Most notebook computers are powered from
a "Limited Power" source, hence no abnormal testing.
(The battery is NOT a "Limited Power" source, but if it
is provided with a fuse, then it is a "Limited Power"
source.")
2) IEC 950 for notebook computers or ac adapter or both?
The Scope of IEC 950 states, "This standard is applicable
to mains-powered or battery-powered information technology
equipment..."
The Scope would therefore include BOTH the computer and the
ac adapter.
However, in some countries (e.g., USA), low voltage equipment
is exempt from third-party safety certification.
Best regards,
Rich
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Richard Nute Quality Department
Hewlett-Packard Company Product Regulations Group
San Diego Division (SDD) Tel : 619 655 3329
16399 West Bernardo Drive FAX : 619 655 4979
San Diego, California 92127 e-mail: [email protected]
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