Batboard

Im looking for a good DC to AC inverter to use in my truck for my laptop & wireless router. Doesnt have to be over 200 watts, but up to 500 wouldnt be bad. I havent had much luck with the black & decker brand I've tried from walmart. They keep going bad on me. I'd like to have a small vanner inverter, but just cant seem to find a used one or anything like that thats affordable. Anyone have anything for sale or any experience with some that are better than others?
Thanks
Craig

Samlex si400hp works good for me, from tessco.

I run a Samlex 600-watt pure sine. Be aware of the input current requirements - the Samlex wants clean power with very little voltage drop at up to 100A. Xantrex/Trace would be another good one to look at. You can safely ignore the cheap stuff at Walmart - most all of it is true junk.

tvsjr wrote:I run a Samlex 600-watt pure sine. Be aware of the input current requirements - the Samlex wants clean power with very little voltage drop at up to 100A. Xantrex/Trace would be another good one to look at. You can safely ignore the cheap stuff at Walmart - most all of it is true junk.

You do realize that the first thing modern computer supplies do is rectify the signal to DC, so that all that matters is that the peak voltage is high enough to keep the input caps at about 170VDC (or 300VDC depending upon the rectifier topography) - thus "true sine" vs. modified sine really doesn't matter, right?

I'd suggest using a secondary battery to run the inverter, so that during vehicle starts the inverter won't be getting too low a voltage - that really abuses the poor things.

Better still would be to get a DC power supply for the laptop, and see if the router can be rigged to run on DC as well, to avoid the RFI issues of the inverter.

Wowbagger wrote:You do realize that the first thing modern computer supplies do is rectify the signal to DC, so that all that matters is that the peak voltage is high enough to keep the input caps at about 170VDC (or 300VDC depending upon the rectifier topography) - thus "true sine" vs. modified sine really doesn't matter, right?

Yup... but I have a few applications which have small AC motors. Motors and "modified" sine waves are not compatible, unless you like the smell of burning electrical.

The second battery is a very good idea, if you intend to run a large inverter.

The DC power supply is less universal, but it keeps you from going DC-AC-DC, and avoids lots of RFI.

tvsjr wrote:

Wowbagger wrote:You do realize that the first thing modern computer supplies do is rectify the signal to DC, so that all that matters is that the peak voltage is high enough to keep the input caps at about 170VDC (or 300VDC depending upon the rectifier topography) - thus "true sine" vs. modified sine really doesn't matter, right?

Yup... but I have a few applications which have small AC motors. Motors and "modified" sine waves are not compatible, unless you like the smell of burning electrical.

Yes, for motors and such a real sinusoid with a power factor as close to 1.0 as possible is a must - however, the OP was about running a computer and a router, so I was responding to that.

To the OP: You will of course notice that both your laptop and your wireless router take DC in anyway - do yourself a favor and do away with the inverter and the AC bricks, and wire up a DC-DC solution. Buy a spare power adapter for your laptop and chop the connector off of it if you have to (if it's one of those funky square Dell ones, for example). The wireless router probably has a pretty standard coaxial connector. Get two small adjustable DC power supplies rated for the amount of current each device needs (which should be fairly minimal in both cases), wire it up, call it done. No RFI, less efficiency lost in DC-AC-DC.

akardam wrote:To the OP: You will of course notice that both your laptop and your wireless router take DC in anyway - do yourself a favor and do away with the inverter and the AC bricks, and wire up a DC-DC solution. Buy a spare power adapter for your laptop and chop the connector off of it if you have to (if it's one of those funky square Dell ones, for example). The wireless router probably has a pretty standard coaxial connector. Get two small adjustable DC power supplies rated for the amount of current each device needs (which should be fairly minimal in both cases), wire it up, call it done. No RFI, less efficiency lost in DC-AC-DC.

You'd probably need a DC to DC converter for the laptop, as many of them take a higher voltage than the normal vehicle 13.8V, usually in the 15-20VDC range. A laptop will probably need something in the area of 5A current.

jackhackett wrote: You'd probably need a DC to DC converter for the laptop, as many of them take a higher voltage than the normal vehicle 13.8V, usually in the 15-20VDC range. A laptop will probably need something in the area of 5A current.

I have seen the DC to DC converters for most laptops at Frys and other computer stores.