Overland Journal: Discovery I, 5-speed

muskyman

Explorer
Mike

this article makes it sound like spikes or ripples in the AC power can cross over through toand affect the consistancy of the DC output.

http://papatek.blogspot.com/2009/03/what-is-power-supply.html

"For critical electronics applications a linear regulator will be used to stabilize and adjust the voltage. This regulator will also greatly reduce the ripple and noise in the output DC current. Linear regulators often provide current limiting, protecting the power supply and attached circuit from overcurrent."
I am in no way any kind of expert on this but I have to think that there is something to the "dirty power" thing.
 
This is getting pretty far afield from Scott's Disco, but . . . The company I used to work for had terrible problems with multiple computer systems crashes. We had the Power Technology Center people from our electric utility come out and monitor our A/C service. They determined that we had very dirty electricity, but couldn'y find a solution. Our (Electric) troubles went away when we moved to new office space.
 

R_Lefebvre

Expedition Leader
Hank, correct me if I'm wrong, but a laptop doesn't run on AC. I can understand how devices that run on AC would be affected by a bad AC wave, but a laptop runs on DC. Again, correct me if I'm wrong, but DC is DC. There's no wave.

It's not really elegant, but in a car / laptop application the 13-14V DC is converted to ~120V AC through the inverter. Then the AC is converted back to about 19V DC with the laptop's adapter.

That is correct.

One problem with the Youtube video that Dan posted is that they are testing it with no load. Once you load the device, inductance will make the square wave more like a true sine wave. Inductors don't work without current, which requires a load.

Also, what they are not showing us is the voltage shape of the power coming out of the 19V laptop rectifier which should have a capacitor on it to further smooth out the power supply. We don't care what's coming out of the Inverter, we care about what's coming out of the Rectifier plugged into the inverter.

I believe a lot of this stuff is bunk. I used to work for Belden, one of the largest and best wire makers in America. They used to make wire for Monster Cables. The wire construction was the exact same stuff used everywhere else, the only difference was the attention to detail placed on the jacket appearance. And that was in the "good old days" of Monster. Now they get their wire from China and it is inferior to Belden wire, but through heavy marketting have convinced everybody it is superior.

I'm not saying I don't think there is anything behind "power quality" discussions. Far from it. But I think this is much ado about nothing when talking about inverters.
 

Scott Brady

Founder
There might be some truth to the affect on Lion batteries in my MacBook Pro. I need to replace that battery every year, sometimes less.

Worth more investigation!
 

R_Lefebvre

Expedition Leader
That's pretty much par for the course with laptop batteries. The two worst things you can do to a Lion:

A)Keep it fully charged and hot. B) Cycle it from fully charged to dead flat.

Both are things that most people do. When you run your laptop plugged in, the charger charges it fully, and the running laptop gets quite hot. This is hard on a Lion. The other thing people do, is run mobile until the battery is dead and they shut down. Then they charge it when they can. This also is hard on a Lion.

The best thing to keep your Lion alive is that when you're plugged in to power, charge it half way, then remove it from the computer so it doesn't get hot. Only fully charge it when you need to go mobile, and shot down when you're maybe around 25%. Now, who does that?
 

njtaco

Explorer
So I can run my Toshiba on shore power with the battery removed?

Also, if there is any doubt about whether a modified sine wave invertor is bad for my laptop, why not spend $100 on a pure sine wave model, just to be sure? I'd spend that on a UPS/surge protector at home, why not for the truck?
 
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R_Lefebvre

Expedition Leader
So I can run my Toshiba on shore power with the battery removed?

Also, if there is any doubt about whether a modified sine wave invertor is bad for my laptop, why not spend $100 on a pure sine wave model, just to be sure? I'd spend that on a USB/surge protector at home, why not for the truck?

Probably can remove the battery.

If anybody *wants* to spend the money on pure sine wave, knock yourself out. There's no good reason *not* to. I'm just saying that you don't have to.

You shouldn't have a computer with you anyways, it's called "getting away from it all" for a reason.

We all have our own vices when camping. Some people carry laptops. Some people carry a lot of camera equipment. Some people carry really fancy knives so they can make sushi.

Some people hike or canoe for camping and think any gas powered vehicle is unnecessary and spoils the atmosphere.
 
H

Hank

Guest
Having a computer and having Internet access are two different things. My laptop is my GPS, my maps, my phone book, my MP3 player, my OBD2 reader, my tech manual, memory card dump, etc... As much as I hate the way it looks, fits, and goes against the rules of "camping", it's too much of a time saver to leave behind when needed.

But it's when using it as an MP3 player that I noticed something was not right. I have the laptop plugged into my stereo via an 1/8" plug. When the inverter is off, everything is good. But when the inverter is turned on, the music has a "buzz". This is what made me look into this some-years ago and that's when I found out the difference between pure and mod sine wave.

About that same time this really small company in town called Rosetta-Stone was having issues with computers dieing. In fact, Rosetta-Stone spent big $$$$ for all new MAC computers for everyone in the office and replaced thir PCs. My ex-wife received her MAC Pro and 3-moths later the battery was done. The computer crashes did not go away with all new equipment. Long story short, it was "dirty power". This was probably a combination of old wiring in the warehouse Rosetta-Stone lives in, and the power from the sub-station. Rosetta-Stone/Fairfield Language installed an electronic device to "clean" the power into a more stable wave. It worked, and that also sparked my interest on the subject.

We've all probably got "dirty power" in our homes or offices. It's just not as dirty as others or not bad enough to cause problems. Visit an audiophile forum and you'll learn more than you'll ever need to know about that. My ear, or budget, has no idea what some of those guys are trying to say, but it all relates back to dirty power.

Anyway, we know there is "dirty power". That's a fact. We know items such as Laptops are sensitive electronics. So why would you even risk plugging your $1,500 computer into a $29.00 inverter? It has nothing to do with Monster Cables, and it has nothing to do with how much load is applied. Dirty power is dirty power, and dirty power can harm electronics.

You'll spend $270.00 on a deep cycle battery, $400.00 on a camp stove, $200.00 for a pair of sunglasses.....why not spend $130.00 on a quality inverter? I mean come on....it like using a surge protector on your desktop....you just do it.
 

Scott Brady

Founder
You'll spend $270.00 on a deep cycle battery, $400.00 on a camp stove, $200.00 for a pair of sunglasses.....why not spend $130.00 on a quality inverter? I mean come on....it like using a surge protector on your desktop....you just do it.

Good point Dan. I have not researched inverters much, but this discussion demands a more detailed look. Xantrex makes a few nice ones. It looks like the pure sine wave models in the 400-600 watt range are about $400. Where have you found a pure sine wave inverter for $130?

Thanks
 

sinuhexavier

Explorer
Says the man that always packs a computer... LOL.

2051602072_d39d29abc1_o.jpg

What do you mean?
 

R_Lefebvre

Expedition Leader
But it's when using it as an MP3 player that I noticed something was not right. I have the laptop plugged into my stereo via an 1/8" plug. When the inverter is off, everything is good. But when the inverter is turned on, the music has a "buzz". This is what made me look into this some-years ago and that's when I found out the difference between pure and mod sine wave.

Do you know for a fact that it wasn't RF coming from the inverter? You're talking about transmitting an analog signal using a completely unprotected parallel wire cable, that was probably routed close to a leak device.

Anyway, we know there is "dirty power". That's a fact. We know items such as Laptops are sensitive electronics. So why would you even risk plugging your $1,500 computer into a $29.00 inverter? It has nothing to do with Monster Cables, and it has nothing to do with how much load is applied. Dirty power is dirty power, and dirty power can harm electronics.

Monster Cables markets "clean power power bars", that's how they got dragged into this mess. They make crap people don't need and sell to them with dubious marketing. If you don't even know how load applies to any of this, you don't know much about electrical power.

Was your ex-wife's battery on the recall list? http://www.apple.com/support/macbook_macbookpro/batteryupdate/

Did she follow these tips from Apple on how to care for her batteries?
http://www.apple.com/batteries/notebooks.html

Apples sells this Inverter for use with their laptops, which is NOT a "pure sine wave" inverter.
http://store.apple.com/us/product/TH995LL/A

Why would they do that?
 
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michaelgroves

Explorer
I researched this quite a bit when trying to choose an inverter for our 2 year RTW trip. I decided it was worth the money to buy a top-of-the-range true sine wave 2000W inverter. We had a LOT of different 230V electrical stuff that took power off the inverter. It worked perfectly, until it got fried en route (my fault), about 1/3rd of the way through the journey.

So in Guatemala, I bought a cheap 500W Modified Sine Wave inverter, which did the same job for the rest of the trip. There wasn't a single item that didn't work just as well with the MSW as the TSW. I had the other one repaired in the States, but never bothered to use it again.

These days, the price difference has closed quite a bit, and I would still be a bit tempted to go for a TSW inverter, but there's no way I'd pay a significant premium. There's a reason the market (and not just the Canadians) buys the cheaper MSW units, and that's because they work JUST as well for almost all the common applications.
 

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