DC-DC or Inverter for Laptop?

rosscarlson · 06-12-2007, 10:08 PM

So I'm going to use a Thinkpad laptop as the PC in my CarPC. I have a 07 350z and I'm planning to install it in the glove box with a 7" touch screen in the cubby.

My question is which is better, a DC-DC adaptor (I can get one for about $60) or an Inverter, which I guess would be more expensive (to be big enough to run a laptop). This is an older T40 series, so a Pentium M 1.6GHz.

One benefit of the Inverter is I would install it in such a way to give me a "power plug" in my car if I ever needed it for something else. So the question is would a DC-DC adaptor be better in some way?

Thanks,

Ross

RedGTiVR6 · 06-12-2007, 10:17 PM

Please check the FAQ link in the navbar above.

There are FAQs written specifically to answer this kind of question.

Good luck.

rosscarlson · 06-13-2007, 03:50 PM

Thanks for the no-help reply. I have read the FAQ, nothing I can find talks specifically about LAPTOP computers. They refer to desktop power supplies, etc, but not laptops. That's really what I need to know about...

Anyone else know?

Thanks,

Ross

RedGTiVR6 · 06-13-2007, 05:40 PM

wow - good luck on your own!

the information is there, you just choose to not read or search for it.

you're not going to haev much fun with this project at all...

especially considering this question get's asked almost DAILY around here...

greatwhite · 06-13-2007, 05:47 PM

There's lots there about the topic.

Desktop or laptop makes no difference.

I will offer you this though:

If there's a car adapter for your laptop, that's what I would go with.

You'll still have to adress the startup shutdown options.

A low buck way would be to hack the laptop and wire in a power button, then just set the power options in the laptop to shut off after a couple mins on battery power.

One more piece of advice:

try turning the other cheek when you get a response you don't like. Getting snarky with a respected member like Red is never a good idea. Especially when she's right.

Cheers

BJ

*edit* I also see darque is watching, I'd watch my step if I were you. Just a word of caution.

mocars2 · 06-13-2007, 06:51 PM

I know what you guys are saying - being new here but old to other forums , when you see the same question over and over it does get old. But if you guys have a great thread or 2 that you know would be perfect - maybe reply with link to that. You know when you do a search for say laptops - you get a whole bunch of stuff coming up actually over 500 posts. In the Faq I didn't really see much about laptops per se maybe there could be one topic for that - just a thought and observation from a nebbie

jwlionking · 06-13-2007, 07:26 PM

I would think a mp3car employee should have turned the other cheek with this comment. Respected? Not by me now. Sorry I made purchases from mp3car if the other employees are like this. This kind of attitude on forums sure is common... Haven't seen it on here in a while.. Hope this isn't a sign. He was respectful on the first post and then was not in this post.. Wow these kind of people infuriate me.. Ok.. Enough of my rant, now to HELP a fellow hobbyist.

This is how I accomplished a similar effect of the powersupply w/startup and shutdown controllers:

Power : Inverter - Power this with a relay which turns on and off with your ignition

Auto turn on - I purchased this item - http://www.mp3car.com/vbulletin/powe...rn-module.html

Auto Turn-off - In adjust power properties in windows on laptop - set it to go into standby when running on batteries - I set mine to 2 minutes

The auto turn on module comes with wire and a momentary switch to run up to the front of the vehicle works as an emergency switch. There are wires that you need to solder to your switch on your laptop.. I purchased a docking station so there was no damage to laptop.

Hope this helps!

Quote: Originally Posted by RedGTiVR6

wow - good luck on your own!

the information is there, you just choose to not read or search for it.

you're not going to haev much fun with this project at all...

especially considering this question get's asked almost DAILY around here...

lbridges · 06-13-2007, 07:33 PM

Quote: Originally Posted by mocars2

I know what you guys are saying - being new here but old to other forums , when you see the same question over and over it does get old. But if you guys have a great thread or 2 that you know would be perfect - maybe reply with link to that. You know when you do a search for say laptops - you get a whole bunch of stuff coming up actually over 500 posts. In the Faq I didn't really see much about laptops per se maybe there could be one topic for that - just a thought and observation from a nebbie

I'm far from being an old hand here, but I'm also an experienced forum member in other venues. As a counterpoint, I'd like to offer that the first reply said to look at the faq.

The very first faq that appears on the pull-down menu discusses the difference between DC-DC converters and inverters (the question asked).

I hate to sound pedantic, but...if a person doesn't know that the only real differences between a laptop and a desktop is expandability (less for a laptop) and a built-in UPS (of sorts - the laptop's battery), then honestly don't you think a carPC project is probably past their skill level anyway?

Just my $0.02

HyperZulu · 06-13-2007, 07:49 PM

Skill level nothing! Everyone has to start somewhere.

I don't like pushing people off with a simple RTFM or such, but this is one of those kinds of questions that is so common that it gets that response almost as a knee-jerk reaction. If you find over 500 posts on laptops, I'm sure a few of them address the topic in question.

That being said, newbies sometimes don't really even know what to look for or what they're looking at so, these kinds of posts are inevitable.

I'd say use an inverter for simplicity. And then to make it cool and complex, build a robotic arm that's programmed to push the power button when the car's ignition is on the ON position and again when it's off.

I don't think you need a super duper inverter. All the Dell laptops I've ever seen use 90W and below for their adapters. I have some IBM Thinkpads at work, but I can't remember their power ratings. I can't imagine they are much different.

DarquePervert · 06-13-2007, 08:12 PM

This hobby is not now, nor has ever been for those who aren't willing, able, and capable of doing some research to find out information.

And what's the purpose of compiling FAQs for easy reference when we're supposed to answer the same question over and over again, by jwlionking's logic.

The fact is, many members have spent a good bit of time and effort compiling information for those FAQs and adding to them. Why? To answer the obvious questions that newbies ask over and over again.

When someone is pointed in the direction of the FAQs for an answer, it's not a brush off. It's simply saying "your answer is over here." If you're not willing to look for your answer, especially when you're pointed in the direction tos tart looing, then you really have no business in a hobby that requires as much research and planning as this, plain and simple.

jwlionking · 06-13-2007, 09:57 PM

Trust me, I understand the importance of keeping forums clear of repetitive questions.

However, Just curious, did you research the true issue before you posted? I did.

Quote: Originally Posted by DarquePervert

And what's the purpose of compiling FAQs for easy reference when we're supposed to answer the same question over and over again, by jwlionking's logic.

RedGTiVR6 · 06-14-2007, 07:52 AM

search string:

"power laptop"

in the newbie forum. First result:

http://www.mp3car.com/vbulletin/newb...questions.html

third result:

http://www.mp3car.com/vbulletin/newb...er-laptop.html

search string:

"power laptop"

in the power supply forum. second result:

http://www.mp3car.com/vbulletin/powe...wake-link.html

DarquePervert · 06-14-2007, 08:29 AM

Quote: Originally Posted by jwlionking

Trust me, I understand the importance of keeping forums clear of repetitive questions.

Uh huh....

Quote:

However, Just curious, did you research the true issue before you posted? I did.

I don't really need to. I've been hanging around here long enough to know what information is and is not in the FAQs, as well as in other areas of the forum.
I know what has been discussed and hasn't been discussed. If I were the statistical type, I'd pull numbers for topics of discussions and put them on pretty charts and graphs to display. Fortunately for you (and probably everyone els), I'm not that sort.

Why do I know what is discussed over and over again? I actually read the forums. Nothing major. I'm no better than anyone. I don't have any insider knowledge or super powers. I simply pay attention.

To recap:
The OP wants to know if it's better to use an inverter with his laptop-based setup or a DC-Dc power supply (car adapter). The overwhelming majority will say DC-Dc power, as it doesn't do the double-coversion from DC to AC and back to DC. There is also less risk of noise being introduced into audio and video signal. Also, inverters that are not pure sine wave inverters generaly don't play nice with laptop batteries.

I don't need to search the forums to know this. Why? I've read and answered the same questions over and over again. Just like crtamming for an exam, the information has been beaten into my brain, like it or not.

wniemcow · 06-14-2007, 08:39 AM

Guys being new to these boards myself - and so excited to start a cool new project (something i knew nothing about until stubling on this website - its hard not to jump right in asking questions.

I know i did.. but i will add I also did alot of searches prior to posting.. With that being said my advice would be to runa few searches and then ask the question a tad different.

"Guys, i have did some searches about XXX - but in your honest opinions am i better off doing this or that (shows you done some research - gets maybe a out dated topic brought back up - new people offer new insight, new products, etc..) "

As i said before, i am new to these boards, and everybody has been more then helpful and very knowledgable about CARPC. (I have also been "hyping" this site up to others i meet and interested in same project)

rosscarlson - welcome to the boards. Its not always this tough

Ohh yah, so whats better the inverter or power supply J/K

(From what i read) its always better to use one of those mac daddy power supplies - you get the turn on turn off feature and the inverter is harder on your battery (right?) Also, the inverters tend to burn up? Sorry i read up on this a while go - cause i was thinking of doing something similar.

Anyhoot!

jwlionking · 06-14-2007, 08:56 AM

Ok, I will spell this out for you two. You pointed to the FAQ. Nothing specific there. You gave references to other areas in your comeback replys.'

Honestly, you two have been around a long time and have a lot of knowledge. Number one, don't judge someone by a number on a vbulletin forum. That doesn't account for their experience.

I have a feeling you two are getting jaded. Maybe you should sit back and think about what this forum is all about because you two are pushing it away and also making some of us think poorly about the retail site mp3car.com since you two are representatives.

For example these are right in the Forum rules:

Super Moderators

The Super Moderators do their best to maintain order and civility on the forums. They are all long-time members of the mp3car.com forums and were chosen because of their fairness and objectivity, as well as their general knowledge about the hobby, which is often put to use assisting other, newer members.

These forums exist as a community of hobbiests helping hobbiests, but also as a resource for other individuals to gain information about how to implement CarPCs in their business model.

How are you instilling this by scolding new people to the hobby and attempting to show the rest of the group your authority and experience?

All that effort and work you put into trying to prove a point to me is what we need for the new guys on the block.

How come you didn't do this for rosscarlson or the others you rebuke?

Please, in all sincerity, think about this.