Managed to get my old old laptop playing MP3's and outputing sound into an old CD carkit tape converter.. :)

Tried it out last night in the car and it all plays with suprizingly good quality (as good as the MP3 anyway), through my Kenwood head unit. The CD Rom drive seem to read about 5seconds of music ahead so no skipping occurred even with very spirited driving. :D

Next thing I need to do is source a cheap way to power the laptop from the cars 12volts as the battery will probably only last 1.5 to 2hours.. :(

Then mount the laptop on the dashboard somehow to allow setting up of a playlist by the passenger or before I start my journey.
This will be a tempory mounting as the eventual plan is to add a keypad and LCD display etc.. ;)
Need to disable the sleep mode which the laptop goes into when you shut the screen down too at that point so I could mount the laptop under a seat or similar.

Later plans include a larger laptop harddrive as at 1.2Gig, there is not much room for MP3's, but the CD rom drive allows for 700MBs and there is about 300MBs of space on the laptop.
I am sure if I reformat the drive and install just the bare minimum I should find a little more space for the time being anyway.

Anyone know a good place to get a 12v to 240volt converter or a 12v for laptop converter? :)

Also ages ago I remember seeing links on here to someone who had done similar in a Scooby but with a desktop PC, lost all my links when I changed job.. is the guy on here or anyone got links to his website? :)

Cheers

JGM :)

Screwfix (http://www.screwfix.com/) do a 12 > 240v invertor for £40.

Superb.. cheers..

Might be more handy that a proper laptop one too thinking about it as I could fit other 240volt items at a later date and use it when camping.. playstation, tv etc..

Cheers

JGM :)

Maplins 150W inverters were 29.99, and 300W were 39.99. Dunno if the offer's still valid, but I got one.

If it's a toshiba laptop, check morgan-auctions.co.uk as they have the converters on there daily for no reserve. Mine cost me a tenner. :D

Cheers Chiark..

I do not understand 150W or 300W? the screwfix one was 150W, will 150W be adiquete? I suppose a laptop will not draw many Watts but a laptop and a couple of other items would.

It is an Olivette laptop..

Was it not your website I looked at previously?

cheers

JGM :)

What, chiark.com (http://www.chiark.com/scooby/limp.asp)? ;) Yes, that's me. :D

150W vs 300W is just the power output of the AC supply. 150W should be adequate for the thing, just check on the base of the PSU as that should give an indication of the current in. Power = Voltage * current, so if you're drawing more than around 0.8A-ish you'll be in trouble with 150W.

Oh no it sounds like a school science lesson... flashback!!

<slap> snap out of it..

So if I went for a 300W I could then expand later or use it for camping and running more than one item etc..

I guess it would only use as much as the car battery power as you were drawing? so no difference in battery consumption between 150W and 300W with the same item attached?

I shall have a look at your website when work is quiet :)

Cheers

JGM :)

It's a bit messy going from 12v DC to 240V AC back to 22V or 12V (whatever the laptop wants...) And it's not going to be efficient.

Try Traco power (http://www.tracopower.com/products/index.htm) for some sensible isolated power supplies. They should have one to suit your requirements. There are plenty of other companies out there making similar products too...

They are available from RS and Farnell

(I know it's more effort getting the design work done, but I think it could prove to be worth it :) 50Hz noise getting into things will prove to be awkward!)

Way to complex for me...

thinking that there must be a way of getting from 12V to what the laptop wants... intend looking into whether Olivetti do a converter, just keep forget to write down the info from the laptop power supply..

Cheers for the website info though, I shall try and make head and tail of it..

JGM :)

If you let me know what the laptop wants - both voltage and power or current requirements, I'll give it some thought. (I need to do something similar for my "father-out-law's" yacht laptop)

Targus do a lot of car chargers for laptops www.targus.co.uk should help.

I'm looking into doing this slightly differently.

Using the top case, an existing hard drive and ram.
http://www.ultim8pc.co.uk/index.asp?section=products&idd=2

A motherboard from the same suppliers is £60 which has onboard graphics card with tv-out (rca and s-video) and a 800mhz processor
The best bit is, the case requires a 12 volt input and is silent.
I havent worked out what to do for control or video yet, but it'll do the job

Looks an interesting case and mobo, especially for this use. I'm going to re-do my display soon with an LCD panel. At the moment, I'm using a matrix orbital display which also acts as the input too, which is nice.

You could just use a numeric keypad for control, and either a cheap TFT LCD or something else like the matrix orbital stuff... I think maplin also do displays now.

Just done a bit more digging - it'll need a well regulated 12v power supply. Your car supply can be anywhere from 9v to 16v, with transients that'll be scarily peak-ish.

If you know how to get around this, good. If not, you'll need some help. It's beyond my knowledge.

Got a 12gb laptop hard disk around here somewhere... Make me a sensible offer and its yours...

PS did the same myself for a bit with my Dell, fortunately I had a 12volt adaptor for the Laptop, which is probably better than buying an invertor if you have a separate PSU.

If you need it, I can help with regulated 12V supplies. It would be much more efficient than running an inverter, but if you want big current, there is still going to be a little bit of heat to throw away (no more than you'd get from an average header unit, though)

Any idea of peak and/or maximum sustained current draw?

Phil

www.mp3car.com has a bbs that will answer any questions
you may have ...........

HTH