Re: Transformers

M.D.Fischer (mf1@UKC.AC.UK)
Sun, 29 May 1994 04:14:23 +0100

The following is based on considerable experience, but should be taken
only as advice.

Most 'name brand' laptops/notebook computers sold outside the US have a
universal power supply unit which typically will adjust to voltages
between 90 and 300, although they usually say 100 to 240. Most of these
adjust automatically. All that is needed is a set of travel plugs (not
a transformer). In the US you should be able to contact the
manufacturer and buy a European or Asian PSU for their model. First
check the small writing on the PSU and make sure it is not already a
Universal one (it will say 100-240 vac on the case).

An alternative for all the countries on the list but Japan is a small
travel transformer which states it is for use with electronic devices
and supplies at least 50 watts. Do not get a transformer which is
intended only for electric shavers, as this will at best not work and
at worst damage your PSU (though not your computer). An excellent model
is sold by the Rand McNally Map stores with travel plugs for about
US$15. Japan will probably pose no problem, since 100v is only about
10% off USA levels and most PSU supply at least 25% more voltage than
is required. However the PSU may run hotter.

It may also be a good idea to get a small surge suppressor. If you have
a universal PSU it will adjust nicely to even large swings in voltage,
and since the computer is actually running off batteries the computer
will not be affected. However, it will not protect you from 'spikes'
in the supply voltage which can reach 1000v or more, and which can
damage your PSU or computer.

Michael Fischer University of Kent email:

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