Joe writes:

>Bruce Toback writes...
>
>> There are two possible causes for the erratic behavior of your computer.
>> The most likely one is that you didn't use a transformer as a step-down,
>> but rather a rectifier. If your "step-down" was very light and offered to
>> power things like lights and heaters up to 1,000 watts, it's a rectifier.
>
>This might be the problem.  The transformer was of the 1600 watt variety...

If you can pick it up with one hand and it's spec'd for anything over 100
watts, it's a rectifier rather than a transformer. A 1600-watt
transformer would weigh ten pounds or more. You can use the rectifier
only with loads that are AC/DC -- again, light bulbs and radiant space
heaters, or the rare motorized appliance with an AC/DC motor.

A rectifier simply blocks alternate half-cycles of AC, resulting in
pulsed DC. The RMS (think "average", though it's not quite the same)
voltage of the output is half that of the input, exactly what's required
for resistive (heating) loads. But the output waveform peaks at about
340V, rather than the 170V that the load sees when connected to 120VAC.
Obviously, this can damage electronic equipment that's not designed to
handle it.

People buy the rectifiers because they see a $15 small, lightweight box
that can handle 1600 watts, and compare it to a $30 big, heavy box that
can only handle 150. But the rectifiers are pretty useless to a traveler.
There should be BIG warning notes on the boxes.

-- Bruce


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