I want to be able to power my laptop (Inspiron 600m) in the car, and I have read some suggestions, both in this forum and elswhere, that say that a power inverter is a better deal than an auto/air adapter: inverters are cheaper (under $50), will definitely allow the laptop to charge (which some auto/air adapters won't, for some laptops), and more versatile since they can be used with any appliance within the inverter's power limits.
But I have also read a couple of things that make me wonder if the inverter is a good idea for a laptop:
1) The cheaper inverters put out a modified sine wave, rather than a pure sine wave. (Pure sine wave inverters are much more expensive, over $100.) A couple vendor websites I have seen say that some laptops won't work properly with modified sine wave input, and to check with the laptop manufacturer. Does Dell say whether or not Inspirons--specifically the 600m--will work with a modified sine wave?
2) At least one inverter was described by the manufacturer as "much less likely" than a generator to damage sensitive electronics. Does that mean there is still a reasonable danger of damage to a laptop with an inverter (compared to when plugged into a wall outlet)? And can this danger be reduced by using a surge protector?
Finally, if any 600m users have used an inverter and can tell me whether it seemed to work fine or not, I'd like to hear it.
Could you say why you recommend the pure sine wave inverter? They're expensive, so it would be cheaper for me to get the auto/air adapter if the modified sine wave inverter won't work or might damage the computer.
Thanks; that's very helpful.
Others who are interested in an inverter for running a laptop might be interested to hear what Dell tech support finally told me:
"The AC adapter for the Inspiron 600M needs a DC inverter that outputs Modified Sine Wave. But I would suggest that you get the Dell recommended auto adapter which is available from our sales department."
That's a little more straightforward than the answers some other people report getting from Dell (such as "I don't think it will hurt your computer...").
I thought I would post this message regarding the use of surge suppressors. Below is the response I received from a technical support rep from Tripp-Lite regarding the use of surge suppressors. I had purchased a 350w inverter from them and I noticed when I plugged in my Tripp-Lite notebook surge suppressor into it the ground lite did not light up, but it did when I plugged the suppressor into my Coleman 800 watt inverter that I have hard wired to my vehicles battery.
I no longer use surge suppressors on my modified sine wave inverters after reading the reply I received. Once I can afford one I am sure I will just get a pure sine wave inverter.
"Thank you for your inquiry. Our inverters have a floating ground & the
unit will have no reference to ground. You cannot plug a surge suppresser
into a inverter, this can possibly cause a catastrophic failure of either
the surge suppresser or the inverter. Inverters output a modified sine
wave & surge suppressers only recognize a pure sine wave. The surge
suppresser will act against the modified sine wave because it is not
recognized & possibly cause the surge suppression components in the surge
suppresser to explode or the inverter to become damaged because it is
receiving a feed back of its own power."
Dell sells TrippLite 200W and 400W power inverters on their web site. Considering they're half the price of the small Dell car adapter, they're probably not pure sine wave.