Message text written by "Darling,          all I want is that you should be
a pinhead -- Arlene Croce"
>I have a 220 pump from Spain.  I have forgotten: do you burn out the pump
if
its 110 and you plug it into a 220 outlet, or do you burn it out if you
have
a 220 pump and you plug it into 110?  Or both?

Sign me,  Third Rail<

Depending on the nature of the device, 220 devices run on 110 will either
run at 1/2 speed or not at all. You may try out the pump and see if it
works well enough to use. Electronic devices which convert the AC input to
DC with an internal transformer probably won't do anything, but if they
work at all, they are probably OK. 

The danger is in plugging 110 devices into 220 where the higher voltage
will cause damage. Voltage converters cut the higher voltage to lower. Most
of them are too wimpy to use with anything that takes a lot of power. I
don't know how well it works turning 110 into 220. It would I think double
the amperage demand (Ohm's law). Computers now usually have dual voltage
capability built in and only need the appropriate cord with plug for the
country you are in. As they all use one of two kinds of attachment to the
power supply, any electronics store could sell you one. 12 years ago, I had
an old laptop which did not have a dual voltage power supply, and my travel
converter failed while in Egypt, passing 220 volts back to the computer.
Its power supply burned out but I didn't know that until the battery died.
Even then I did not attribute it to the travel converter. I had assumed
that a properly designed converter would stop passing current if it failed.
If you use a converter which is not up to the demand, however, it may just
give up and let all the juice go through. The dual voltage supplies used in
most computers now (saving the manufacturers from having to make different
models for us than for most of the world) simply block voltage greater than
110 from going through, then convert the 110 to their operating DC voltage
(usually 12). Consumer electronics such as radios, TVs, stereos, are
usually not dual voltage although these are available. Since there are
usually other regional differences as well (radio frquencies, TV scanning
systems) presumably the mfgrs don't find it cost-effective. 

Sign me, Not Off My Trolley

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