To all drivers who run a laptop and an inverter all day. PROBLEMS SOLVED!!

[freedomrider1]

install.jpgFor 6 years I have run a laptop mounted in my truck using an inverter to power it. As we all know running an inverter generates RFI. Can't hear far on the CB, no AM radio.

Well after all that frustrating time. my problem in solved. Your's can be too.

Auto Power Adapters, Auto Air Adapters and Power Packs for Laptop and Notebook Computers.

What we have here is not an inverter. It's a step-up transformer. Plugs in to 12v and puts out 15v or 19v depending on your computer's requirements. They have specific models for all computers. A little over $100. best money I've EVER spent trucking.

[Rev.]

Lol spam

[freedomrider1]

Hardly. Just sharing my good fortune with other drivers.

[VPIDarkAngel]

Hmmm, that's funny. I never had any RFI problems with my laptop and any inverter I've had (including the TriPac factory inverters). Then again, that site is useless to me, because Apple still won't let anyone else produce power adapters for MacBook Pro's.

[Rev.]

Hmmm, that's funny. I never had any RFI problems with my laptop and any inverter I've had (including the TriPac factory inverters).

Me either. If you're getting interference, then your system isnt set up properly, or you're using shoddy equipment.

Again I say: LOLSPAM

[flood]

Me either. If you're getting interference, then your system isnt set up properly, or you're using shoddy equipment.

Again I say: LOLSPAM

i'm with the rev 100% on this one, 6 years 5 laptops and 3 inverters (use 3 laptops at the same time now 1 for gps always running, 1 for log's always running, and 1 to get online in the bunk) and we use a cheap ***** road-pro 1500 and the only interference we get is from the power window on the drivers door over the cb when the window is going up.

[YerDaddy]

Aren't they called 12 volt DC chargers? What a revolutionary idea!

[ronjon619]

Hardly. Just sharing my good fortune

uh huh......

[freedomrider1]

You guys must REALLY think I just fell off the turnip truck. First I hold an Extra Class Amateur Radio license(I got a clue). Second...shoddy equipment. I even bought a 250 watt pure sine wave inverter look up the price on those. It helped but it didn't clear it up. Your regular inverter you buy at the T/A is called a "modified sine wave" inverter. They produce noise. Remember the lines on your old analog TV? You either have your RF gain turned way down or your full of it. Sorry, I call em as I see em.

Here's something to read. [url]http://en.wikipedia.org/wiki/Sine_wave_inverter#Output_waveforms [/url>]
If you can comprehend it.

All switch-mode power supplies make radio-frequency noise regardless of whether the output of the supply is a sine wave, a square wave or dc or whether the input is dc a sine wave or whatever. Power inverters used in boats and recreational vehicles are subsets of the general class of switch-mode power supplies. The quantifiable amount of RFI generated varies with design, implementation, and installation.

The designs which minimize the generation and propogation of noise cost more than virtually any product which you will see available (at least now and the near future) and affordable for use in the marine market, especially the high power units which are bi-directional in that they operate either as a charger or as an inverter. Just as a comparison, we "enjoy" being able to purchase an inverter/charger for less than a dollar per watt (in the USA) yet if you purchase a "relatively simple" dc/dc converter which complies with international standards for conducted and emitted RFI (radio frequency interference) you might pay 50 dollars per Watt.

Conducted RFI is interference which is generated through the conductors (either input or output) and anything connected to such wires must have internal rejection of such interference to escape its effects. Most marine and RV installations suffering audio system and radio system interference suffer from conducted RFI first and emitted RFI second. Because there are many boats with installations suffering essentially no problems with their audio, radio, tv, and computer systems (having your specific model of inverter/charger) the first "thing" to look for is just how your unit is wired in that might effect conducted interference.

Emitted interference is the most difficult to solve and the "easiest" method is merely to provide as much geometric separation between the source and the reciever which means separating the wires and units as far as possible to take advantage of the phenomenon that the susceptibility decreases as the reciprical of the distance squared. The easiest method of preventing the generation of interference lies with the design and physical packaging....not something that you can likely change. Shielding of either the source or receptor is always bandied about within the marine community yet the truth is it is a waste of time because of the difficulty in being able to do a proper job (which very few people are capable of doing either in theory or in practice) especially when considering the level of power that has to be dealt with in the case of inverter/chargers. Really effective shielding uses continuous enclosure of the source with material that shields both the electric and magnetic fields....that means using ferrous materials and magnetic materials...who has that capability? (that means that aluminum foil and copper braids, etc. just will not satisfy the total requirement).

Twisting together the input power positive and negative cables introduces coupling between the two that takes advantage of self-canceling fields (called differential mode cancellation) caused by the "gulping" of power that the inverter takes from the battery in the inverter mode or the battery takes from the charger in the charger mode. Adding capacitance between the two cables filters the voltage fluctuations as well (if needed).

By making sure that the inverter/charger power cables do not share cable runs with your susceptible loads eliminates "ground and power loops" (power loops are the mirror-image of ground loops) you will minimize the voltage fluctions induced into your suseptible receivers caused by the inverter/charger. That is why I advise single continuous leads from the inverter/charger all the way to the battery terminals. Loads should be only attachted to the battery terminals on TOP of the power (inverter/charger or other heavy drain potential sources of interference like refer compressors). No other loads or sources should share wiring with the inverter/charger all the way to the battery terminals. The ONLY exception is a short cable from a battery monitor shunt to the battery negative. All wires must be attached to the load side of the shunt in order to allow the monitor to "see" all sources and loads to/from the battery

[Rev.]

You guys must REALLY think I just fell off the turnip truck.

Sure do!

[flood]

a rookie with only three post and all of them on this tread...........? sure looks like spam to me

[miles]

I don't think so at all. The guy took the time out to try and help others with his first post and then a LOT of time with his last one. I'm looking into it, because I have some of the problems he's talking about. Thank you freedomrider1.

[Musicman]

I have a 2500 watt Tripp Lite inverter and have never experienced EMF / RFI issues. Large inverters like mine stay connected and on 24 / 7 / 365, so what good would buying a DC / DC notebook adapter do in my case? Besides anybody who does have interference issues, can simply add some EMF / RFI shielding and STOP the interference.

[mikewayne]

Why you will need a extra inverter to run a laptop.... it has its own batteries and power consumption is very low!!!!

[Freedhardwoods]

Why you will need a extra inverter to run a laptop.... it has its own batteries and power consumption is very low!!!!

Laptop batteries will last a few hours at best. I am gone for days, not hours.

I did have interference with the 1500 watt Xantrex inverter I used to run. I just bought a cheap 400 watt cobra to run my laptop on. Then I only used the big one occasionally to run my microwave. That solved my problem.

[Blind Driver]

I've never had any problems with my inverter.

[Copperhead]

I used to have issues with RFI when using an inverter, until I put in a Xantrex IP1012 AL unit. It is an external inverter/charger about the size of a group 31 battery. It can be mounted externally on a frame rail if someone wanted to do that. I had room in my battery box along side of the 4 group 31 batteries and I installed it there. You can even take a pressure washer to the inverter with no negative effect. Since the unit is enclosed, and bolted bolted to the battery box so that it is solidly grounded, it has had virtually zero effect on my CB reception. It is encased in aluminum and I think it kinda acts like a Farraday Cage when it comes to RFI. And when shore power is available, it is a pass thru unit and also will charge the batteries. I managed to get ahold of one of the last of these, since Xantrex discontinued them due to slow sales. True, these units are not the high powered 2500 watt units some may need. They were only a 1000 watt with a 3000 watt surge for 30 seconds. But my power needs are more modest than others, so it was a good choice. It is more than enough to simultaneously run my fridge and other goodies in the truck.

I just checked, and if anyone is interested in one of these, I saw a seller on Ebay that had a few of them, new in the box. Xantrex still has the brochure on these online at their website. They are darn good units that will take a real beating. They were designed for tough marine, construction, and trucking environments and can be placed in engine compartments, external rails, battery boxes, or wherever. They are a little pricey, but when you consider that these units are built like a tank and can handle being exposed to just about any environmental condition, you get what you pay for. And they emit very little, if any, RFI.

[Fredog]

I bought a laptop with a wind up motor, problem solved

[Copperhead]

I bought a laptop with a wind up motor, problem solved

LOL. But that would be a possibility, I guess. But, really, one of the small solar power units from places like C. Crane would do the trick in charging up a laptop. There are a quite a few options to get the job done.