You say voltage but I assume you mean wattage.
AC power from the wall is a perfect sine wave, shifting from -110 V to +110 V 60 times per second. Inverters try to duplicate the gradual change of a sine wave and are grouped/calssified by how close they get.
110V wall power alternates from -160V to 160V. The Root-Mean-Square (RMS) of this is 113VAC (close enough).
The cheapest inverters usually just produce a signal that jumps directly from -110 V to +110 V 60 times per second. This is adequate for most things that have a "dumb Brick" type power supply like a portable CD/tape player etc. This is _not_ adequate for something that has a motor driven by the AC current like a fan. I suspect it is also inadequate for intelligent/auto-sensing power supplies.
The next level is an inverter that generates a stepped approximation of a sine wave. Instead of 1/60th second at -110 and 1/60th second at +110, it will be 1/180th second at -110 then 1/180th second at -55 then 1/180th second at +55 then 1/180th second at +110 etc(not exactly but you get the idea). This is good enough for most things. Higher quality units will have more steps and thus be closer to an actual sine wave.
Most inverters below around 1000W use a quasi sine wave. It puts out +160V for 1/4 of a cycle, 0V for 1/4, -160V for 1/4 and 0 for 1/4. This gives 160V Peak and 110V RMS which is the same as a sine wave. Purely resistive loads (such as light bulbs) see only the RMS voltage and are happy. Switching power supplies (like most computer power supplies) see the Peak voltage and are happy. Most smaller transformers have sufficient reserve capacity that they can tolerate the abnormal waveform. The quasi sine wave inverter is fine for most any switching power supply , manually switched, auto switched or wide range input included.
Most any inverter out there should be fine for a 3400s power supply. If it doesn't work I would look for a different brand of inverter.
Rather then trying to figure out if a given inverter could power your laptop, I advise you to just get the DC power supply and not bother with an inverter unless you have other things to power with it.
That is my personal preference as it makes for one less thing to lug along. Especially when running off a portable battery pack which I do.
You could try going into the store and asking if they have any inverters specifically rated for use with laptops.
Most (All??) stores selling these inverters don't have employees with anywhere near the expertise to help. If you are lucky they'll know what an inverter is.
-Eric J --- Brian Braunschweiger <[EMAIL PROTECTED]> wrote:Rather than getting a 12 v adapter for my 3400 when I want to compute
on in the car (usually on long trips with my wife driving), I got an inverter. Unfortunately the inverter shuts itself off when I plug in the PowerBook. Sometimes it happens right away and sometimes after a minute or two. the voltage is well within the inverter's capacity.
I figured the inverter was bad and bought another one but the same thing happened.
> Any insights or solutions? >
-- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting
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