# Building a PC for the van



## spannerhead (Sep 5, 2009)

I want to be able to watch movies from an external HDD to a monitor in the van, both HD and standard quality. 

I've built a few PCs for home use, and I even have an old mini HTPC that I don't use anymore but it's got a 19v Dc supply, so no good for the van.

Does anyone know the easiest and simplest and cheapest way of doing this? I don't care about watching any live TV, just .avi and .mkv files on a HDD.

Can you get a 12v DVD player that plays files from a HDD like you can with 240v? Or do I need to build a machine from scratch?

If there are any existing threads on this please do point me at them, doing a search for pcs just turns up too many wrong results


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## listerdiesel (Aug 3, 2012)

19V supply is quite do-able with a DC-DC converter.

Micro-AT motherboards are quite small these days, you can build something quite small with a full range of ports.

Otherwise, look for a portable DVD player with good resolution.

We've got a load of movies on a 1TB drive that we run through a laptop, plus the Avtex has a built-in player.

Peter


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## spannerhead (Sep 5, 2009)

Great, looks like I just need to sort out a power supply then, thanks 

Anyp idea where to get the converter, had a look on maplins but couldn't find anything?


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## lgbzone (Oct 8, 2008)

spannerhead said:


> I want to be able to watch movies from an external HDD to a monitor in the van, both HD and standard quality.
> 
> I've built a few PCs for home use, and I even have an old mini HTPC that I don't use anymore but it's got a 19v Dc supply, so no good for the van.
> 
> ...


Hi

I think in your scenario i'd use a raspberryPi running xbmc or raspbmc with an 2 1/2 inch external hard drive, a Pi can be had for 30 quid brand new, cheaper second hand, you'll need an sd card to install the free OS onto and it will run off a 5v phone charger (loads exist that run from lighter sockets). supports full HD (hardware) video playback etc and full library functionality with xbmc.

if you had further requirements i'd suggest something else but i'd like to keep that hush hush for now as it's a project i'm looking at and would like to do a write up at a later date :wink:

Lee


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## Ian_n_Suzy (Feb 15, 2009)

Hi,

As above, I would go the Raspberry PI running XBMC route (and if you have an internet connection and are that way inclined, you can have lots of fun with some readily available repository plugins).


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## max123 (May 9, 2005)

Just get a 12v tv with USB and play it from that. A Cello 12v LED Tv with USB and DVD would do the job without buggering about connecting to laptops etc
Steve


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## Ian_n_Suzy (Feb 15, 2009)

max123 said:


> Just get a 12v tv with USB and play it from that. A Cello 12v LED Tv with USB and DVD would do the job without buggering about connecting to laptops etc
> Steve


Hi,

Will the Cello play Matroska (.mkv) files from the USB/DVD? I've not found one myself yet that will play all formats, without having to convert them first to the TV specific format.


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## arh (Dec 8, 2007)

Listerdiesel, what is this dc-dc convertor?, can one be bought that converts 12vdc to 19vdc. At the moment I go from 12vdc into an inverter which comes out at 240vac which I then convert into 19vdc via the supplied ac transformer into the laptop, which I always thought daft. I haven't been able to find anyone able to supply a 12vdc-19vdc convertor.


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## spannerhead (Sep 5, 2009)

Like the idea of a Raspberry, it'll be good to have a reason to have a play with one.

Yeah, the DVDs that play movie files are a bit picky and rarely handle subtitles.

Cheers chaps!


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## Patrick_Phillips (Aug 17, 2006)

The Maplins product code is A73HU http://www.maplin.co.uk/100w-laptop-car-adaptor-with-usb-charging-socket-223912?
They will cope with 100w supply...

Patrick


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## camallison (Jul 15, 2009)

The Raspberry Pi with Raspbmc software is the route I went, and it is great.

Colin


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## listerdiesel (Aug 3, 2012)

DC-DC converters come in a huge range of sizes and ratings, but this one is probably the most suitable:

http://www.ebay.co.uk/itm/290970255308

There are plenty on 'buy it now' as well as auctions.

The input is not isolated from the output, the input and output negatives are common.

Peter


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## Pudsey_Bear (Sep 25, 2008)

listerdiesel said:


> DC-DC converters come in a huge range of sizes and ratings, but this one is probably the most suitable:
> 
> http://www.ebay.co.uk/itm/290970255308
> 
> ...


Isn't it odd that we think 12v DC to 230v AC is normal, but I for one never considered that there would be a 12v DC to 19v DC product out there, we seem to have been brainwashed into using inverters for everything, until Peter pointed me at this one


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## listerdiesel (Aug 3, 2012)

Industrially, DC-DC is big business, especially in automation where you may have 24V DC but no mains supplies.

The price of a typical converter has dropped like a stone over the past 10 years, since the Chinese started making them in volume, a bit like solar panels.

You can get isolated output converters, they just cost more as they have to have a switching circuit and a transformer, whereas these small converters are just an online boost converter.

Drop-down converters are buck, step-up are boost.

Don't forget they will need setting of the output voltage, and the output cannot be less than the input on these types. 

Peter


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## bubble63 (Sep 30, 2009)

camallison said:


> The Raspberry Pi with Raspbmc software is the route I went, and it is great.
> 
> Colin


hi Colin,

you have wet my appetite , I would love to build this with the kids as a practical project

could you give me some more details

type of drive , psu etc etc etc

regds Neill


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## camallison (Jul 15, 2009)

bubble63 said:


> camallison said:
> 
> 
> > The Raspberry Pi with Raspbmc software is the route I went, and it is great.
> ...


The Raspberry Pi is the Model B with USB sockets, power is fed from an old 5 volt power unit that was to charge an old mobile phone - you need 1 amp to be safe. Then I fitted a (powered) usb hub to plug in an infra-red receiver to take signals from a media centre PC remote. The drive I used was one rescued from a dud laptop, 2.5inch, and I put that in a small enclosure made for the purpose.

When I have an Internet connection, via a wifi dongle also plugged in to the usb hub, I can stream BBC iPlayer too.

Just Google RaspBMC and there is a wealth of information, and the software is there to download free. They tend to updat eit about once a month to take account of improvements in XBMC, on which it is based.

Happy computing.

Colin

PS - you do know that the Raspberry Pi team are based in Cambridge?


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## spannerhead (Sep 5, 2009)

Cheers everyone, I think I'll try and sort out the power supply for my existing Asrock Ion HTPC with the charger from Maplins, I'm not great with electronics and the eBay ones look a bit scary!

And if it's no good then it's be the Raspberry for sure


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## TheNomad (Aug 12, 2013)

spannerhead said:


> Great, looks like I just need to sort out a power supply then, thanks
> 
> Anyp idea where to get the converter, had a look on maplins but couldn't find anything?


Here you go:

http://www.ebay.co.uk/itm/300929683383?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I bought one of these just a couple of weeks ago to power an old cheapo secondhand laptop in the MH that I also bought for peanuts off ebay.

Piece of cake to use, as you just set the output voltage on it via a selector, and fit the correct sized diameter of tiny plug thingy for your computer ( it comes with a whole selection of sizes)...then just plug in to any 12 volt dc socket in the MH.

Incidentally, the old laptop I bought works brilliantly as a tv screen to play films/series that we download to an external hard drive and then tether to the laptop via USB..........it also works as a basic unit for wifi and skype; and if it was ever nicked or I drop it, I've only lost 40 quid.


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## cabby (May 14, 2005)

well if you had a tv that had usb socket I would just have them on usb sticks as I do, have about 4x 64gig ones with films on that have been downloaded. you can always update as you wanted and it takes up a lot less room as well.Plus you can take the usb sticks to use in another tv elsewhere.


cabby


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## spannerhead (Sep 5, 2009)

TheNomad said:


> spannerhead said:
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> 
> > Great, looks like I just need to sort out a power supply then, thanks
> ...


Same as what I just bought  Just got to find a monitor now to play it through....

Trouble with the TV's that have USB ports is that they can be picky about the file types they play, often not liking the HD .mkv format, and you can't play files with subs either unless they are hard coded.


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## urbanracer (Aug 22, 2007)

I bought a DC adapter from this company last year looks like an OE product and works OK

http://www.any-batteries.co.uk/adapter-b.php/13


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## arh (Dec 8, 2007)

Thanks for that Urbanracer, cannot find my model number so I have emailed them.


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## bubble63 (Sep 30, 2009)

camallison said:


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## bubble63 (Sep 30, 2009)

bubble63 said:


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## lgbzone (Oct 8, 2008)

bubble63 said:


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## bubble63 (Sep 30, 2009)

lgbzone said:


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## Pudsey_Bear (Sep 25, 2008)

lgbzone said:


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## spannerhead (Sep 5, 2009)

Well the old HTPC I was going to use is officially dead, so I'm going down the RaspberryPi route which I'm quite excited about too!

I can't believe something so small and cheap can output in HD.


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## bubble63 (Sep 30, 2009)

spannerhead said:


> Well the old HTPC I was going to use is officially dead, so I'm going down the RaspberryPi route which I'm quite excited about too!
> 
> I can't believe something so small and cheap can output in HD.


bought mine via the RS web site, easy peasey

arrived today , so the weekend activities are set 8)

neill


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## spannerhead (Sep 5, 2009)

Rs web site too, £43 including case, power lead and sd card with os, free delivery, bargain!!


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## Pudsey_Bear (Sep 25, 2008)

Peter, I bought this one as you suggested and it arrived yesterday, I'm now unsure of the best way to mount it in/on, fuses, cable etc, as it came in bag, no instructions.

The item description does give some info but I don't get it at all.


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## camallison (Jul 15, 2009)

Kev_n_Liz said:


> Peter, I bought this one as you suggested and it arrived yesterday, I'm now unsure of the best way to mount it in/on, fuses, cable etc, as it came in bag, no instructions.
> 
> The item description does give some info but I don't get it at all.


Why not mount it in a small enclosure - your local Maplin store will have plenty of different sizes. Just leave plenty of space inside around it for heat to dissipate. Cabling could include inline fuses on both input and output and it could go through cable glands of suitable size (just to restrain the cables). I am sure you saw the diagram below as to how to wire it. Then just adjust the output voltage to what you want on that trimmer potentiometer.

Colin

[EDIT - the labelling on that diagram is wrong and confusing, but the annotations on the board say, from the top downwards, IN+, IN-, OUT-, OUT+ ..... hope that helps  ]


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## listerdiesel (Aug 3, 2012)

There are four threaded mounting stand-offs, input and output terminals are marked, fuse the input only, the output is current limited, I'd use a 5A fuse.

The fins need to be either vertical if on a flat surface or if you are mounting it on the side of a wall, the fins need to be vertically orientated for air flow.

Wire up the input, turn it on and check the output voltage, adjust as required then connect the output wiring.

Both negatives are in the middle, on this picture the captions are wrong:










If you look on the back of the PCB you'll see the connections screen printed with both the negatives together as below:










Peter


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## Pudsey_Bear (Sep 25, 2008)

Thanks Colin, I've been giving a bit more thought to it since posting earlier & I was thinking 0.5mm2 wire and a 1 amp fuse each +ve side, but the board has 4 brass nuts for mounting so I'll need to take it to maplins to get the right screws, look like M3 though.

Was thinking Stixall instead of glands.


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## listerdiesel (Aug 3, 2012)

I've sent a message to the seller re the connection diagram error.

Remember that the input and output are not isolated from each other.

Peter


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## Pudsey_Bear (Sep 25, 2008)

Thanks Peter, I hadn't noticed the error in the description, but would have followed the board though.

Sounds like you favour an open box mounting, or closed with plenty of drilled holes.

5amp input only fuse noted.


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## Pudsey_Bear (Sep 25, 2008)

listerdiesel said:


> I've sent a message to the seller re the connection diagram error.
> 
> Remember that the input and output are not isolated from each other.
> 
> Peter


I noticed you said that in an earlier post, but what does it mean, do I need to do or not do anything in particular?


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## listerdiesel (Aug 3, 2012)

No need for you to do anything, it is purely a caption error, the PCB is OK.

You do need ventilation at the higher end of the output range, try it and see how hot it gets before you decide.

Peter


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## Pudsey_Bear (Sep 25, 2008)

listerdiesel said:


> You do need ventilation at the higher end of the output range, try it and see how hot it gets before you decide.
> 
> Peter


Right I'll test it for temp once fitted, but I was referring to

"Remember that the input and output are not isolated from each other."

What does that mean and what are the implications for me, being a sparky thicko?

All I need now is to find a matching lead for the laptop, I had this problem with the TV, no one seems to do a made up lead locally and as the sizes are in increments of 0.5mm difficult to size the inner contact, I asked at Maplins and they couldn't size either, you'd think they'd have a set of sockets to plug into for sizing accurately.


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## arh (Dec 8, 2007)

Mine is on the way as we speak, (dc-dc converter). Thanks for the info Peter, I'd already noticed the error but the fuse info is good. I'm thinking a replacement transformer for the plug if I cannot find one any other way. arh.


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## DocHoliday (Jul 18, 2008)

Picking up an old thread here. If you want something a bit more full-featured that will run Windows, you could google Brix. I have no experience of these but they look like a neat, small, high performance PC taking a 19V input. Much more expensive than the Pi, of course.

Most people would be satisfied with a laptop, but somehow the idea of a mini-desktop tucked away in my van appeals.


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