Ok, I have a spare DVD burner, Mother Board and CPU, have hard drives, 7" LCD screen (thanks christian :) )

What is the general consensus on power supplies and what is best

What is the general opinion on software to use and where can I get it.

I am keen to get moving on this project, I have the bits now just need some people who have done this to make some suggestions.

Thanks guys and gals

The easiest way to provide power is to use a standard atx psu with an inverter - not as efficient as a straight dc:dc converter, but with efficiencies of around 90% at both ends, you are not going to do that badly.

I built a few 'puter power supplies for cars - it isn't quite as simple as you would expect, but it isn't really rocket science - you need a high current 5V and 3.3V supply (pretty easy, these are buck supplies) 12V supply (assuming that you never drop below 12V, you can use buck, otherwise this is buck-boost), and -5, -12.

Your 3.3V and or 5V rails are usually the ones that are regulated, with the 12V rails dependent on the turns/volts ratio of the tranny...

If this is all gibberish, just use an inverter and an ATX supply.

Cheers
Heath Young

Thanks Heathyoung. Yes the basic concept is fine but the terms are a bit much for me lol

If I go the inverter route which I am tempted to use as then I can recharge things like a vid camera etc what sort of wattage should I be looking for. There are a few on ebay around the 350 watt, they claim to be able to run a small tv, does this sound about the ball park.

heathyoung

your shooting off some pretty usefull info mate
are you a sparky ?

this is the best site for carputers. www.mp3car.com

Hey Mal,

If you are contemplating the inverter option, this is what you may need to consider...

> How many watts is the computer power supply?

> How many hard drives, cdroms and other peripherals (USB, etc) will you be running?

> Do you plan to run the computer at the same time as other devices (like the camera charger?)

> Where do you plan to install the inverter? (Heat can sometimes become an issue if the inverter is run for extended periods - adequate air flow will be required.


These are just a few I can think of from my experience, if I remember anything else, I will let you know! :)


(P.S I run a 300W inverter for my Carputer, I can also run the PS2 and camera charger at the same time.....My computer is a Shuttle PC though and the power supply is only 200W - running two hardrives and a couple of USB devices, so it may only be using about 80% of the load i.e ~160W)

Most modern PCs have a 300Watt Power supply as standard - still others have 400W, etc etc. AFAIK, laptops have about 100W or so.

Mal! talk to Nick (2much).. He'll be good at that coz he's shown me his finished set up in his car... it's a B-E-A-U-T

heathyoung

your shooting off some pretty usefull info mate
are you a sparky ?

Kind of - IT / Broadcast Engineer (RF/Audio/Video/Computers/whatever) for a radio station, worked at car audio places as an installer, auto electricians, electronic service centre.

Power supply and amplifier design are a hobby :)

Cheers
Heath Young

I figured putting the inverter in the boot where the pc is as i do not want 240 volts running through the car.
I was going to set up a pc fan set through a duct of some sort to bring air from the pass cabin into the bood for cooler air flow given that will be where there is least dust.

This is what I am looking at getting http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=4518127091&fromMakeTrack=true

this might give you some help in finding how big an inverter you need ans power supply
i give you the power supply wattage calculator :D :D
http://www.jscustompcs.com/power_supply/

Im just curious, why do u want a computer in your car? :confused:

I'm not him, but I'd suggest:

o Inexhaustible supply of mp3s
o Cheap sat nav with a USB attached GPS unit
o dvd/divx/mpeg playback
o car phone with a PCMCIA attached GSM card
o Internet when combined with a wireless card and an obliging unprotected wireless network or afore mentioned GSM card for dial-up
o Voice over IP for inter-car intercom if your mates have a similar setup
o games
o and geek factor :D

Options are endless...

But music and in car entertainment would be the biggest me thinks. Or if you're on the road a lot. V.O IP would be mad! Ah toys....

Take into account vibrations with everything carputer related. Vibrations, power supply and heat buildup are the main issues.
Most laptop equipment or dedicated carputer gear is upto the task.

Let us know how u go...

Peace

Tim

Oh - If you go the Inverter method be careful of the type of Inverter you buy. There are 3 main types..

1) - Square Wave
2) - Modified Sine Wave
3) - True Sine Wave

Of course True Sine Wave matches that of our 240V supply. Basically it's all to do with how cleanly the waves of the electricity shape off. The cleaner the shaping the cleaner the power which = happier equipment, especially for sensitive equipment like computers.

You may find a Square Wave Inverter will send you Carputer spastic. It would be best to obtain a True Sine Wave Inverter but it will cost you more $$$$.

How will I go with Modified sin wave, will this suffice do you think

Thanks by the way for all the replies, has enlarged my scope of ideas for it's uses, besides dvd burning and music :)

Will post pics and instructions as I start it all off, will be doing the start pahze in about 2 weeks once we have finished unpacking our gear.

Im telling lucky i ducked again as i would of lost my head.. :confused:

SA Representative...
looks so wierd under you name mal :P

o and geek factor :D

Yes.... Geek factor.... :bowrofl:

How will I go with Modified sin wave, will this suffice do you think


How long is a piece of string? On a serious note it is very hard to say what it will do. You could get random shutdows, lockups or even worse a hardly bootable machine.

Remember computer power supplies are switch mode and are such highly sensitive. I would still recommend true sine wave that way you could use it for any 240V device as long as it doesn't exceed the inverters output (wattage).

Also these inverters draw loads of current so anything above a 300W unit is best wired direct to the battery, not through the cigarette lighter. They do get quite warm too (i used to sell 12/24-240v inverters for years).

Something like this one should suffice :
http://www1.jaycar.com.au/productView.asp?ID=MI5085&CATID=8&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=728

all you need is this,
http://www.mp3car.com/store/product_info.php?cPath=21&products_id=32
I've heard vrey good review on OPUS power supplys
Its main feature is the ability to withstand the voltage drop during an engine crank without rebooting the PC.
but prepare to pay top $$ for it....

i've looked into making a carPC and i roughly know what components and the design so it will fit in DIN slot.
if you look in the forums of mp3car.com, you'll find alot of info that will help you.

Kev

Guys, a computer power supply will work off DC of a high enough voltage - simply put, a computer power supply takes the mains supply, rectifies it to DC (240V X 1.414 - due to sine RMS), then uses this DC voltage in conjunction with a pair of transistors to provide the 44Khz push/pull squarewave pwm voltage to the ferrite transformer, whose output which is then rectified via a shottky diode, assorted inductors, and caps. I wont go into feedback or bootstrapping that is used to provide the low voltage DC to the control circuitry before the power supply has started... :P

Crash course in switchmode power supply design :)

Simply put, you can throw any old crap into a switchmode power supply, even something as ugly as raw DC - I know, I have done it before. I converted a small colour telly to 12V DC with a dead simple 350V DC to DC converter made from bits and pieces around the workshop.

So basically, you dont need anything more complicated than a squarewave inverter, with more wattage than the computer power supply (to allow for headroom and efficiency considerations) - eg. for a 300W supply, a 350W inverter should suffice. However, make sure that it has a decent surge load - the capacitors in a SMPS draw quite a load when they are first switched on.

Like I said, it isn't exactly rocket science.

Cheers
Heath Young

How will I go with Modified sin wave, will this suffice do you think
A Modified Sine Wave (MSW) inverter should suffice.

I have run a few different Carputers for over 3 years now using the same DSE 300W MSW inverter with no problems at all. It still runs perfectly. While Ralliart410 makes a good point, that a True Sine Wave would be better. Provided the computer PSU is of decent quality, you should not have any problems running a MSW inverter.

heathyoung also made a good point about power surge. A computer power supply may not create a large surge, but as he mentioned, an overhead of about 50W should be sufficient - provided nothing else is running off the inverter while you are starting the computer.

i've looked into making a carPC and i roughly know what components and the design so it will fit in DIN slot.
KevThe cool thing about the Magna (TJ anyway) is the amount of room behind the DIN slots. You could install the computer and audio gear all behind here with a cooling fan and no one would be the wiser. You don't have all that stuff filling up your boot and it minimises the cable lengths for all your gear. Replace the left hand plug on the dash (it covers the nut the holds the dash on) with the Sat uplink and have the LCD flush mounted in the centre console removing all dials from the AC (run that using software similar to climate control) no need for radio buttons (simulate those using your own GUI interface - see attached file for example of GUI that I am looking at doing) all you have on your dash is the top screen above the air vents which you replace with a slim LCD that writes up small data whilst the main LCD is sleeping and then a monster 10" LCD colour screen that fills all the way down to the ash tray. Replace the ciggie with USB/firewire/10b100 ethernet ports and hide some more under the dash for more gear. HAve a wireless mouse (a trak ball would be better) and keyboard for rear seat users but you use the touch screen film that you have iunstalled over the LCD. HAve a playstation hooked up under the passengers side (one of the new ones that only requires a 12V to 8V adaptor) in that piece of plastic that does nothing and get a wireless controller for that too.

So you have a TV card for any TV or Radio that you might need. UHF capability. Mobile phone car. Wireless internet car (that docks with your home PC when in the drive way and allows you to remotely synchronise folders)
Also you have a full Sat Nav capability that you have installed road angel software on that allows the car to tell you what speed (and the how dangerous) the road normally is. Also installed a sensitive Police Radar detector but it is all hidden software and hardware so since they don't understand what a farad is you explain that the gizmo hidden behind the front bumper helps with the climate control.
You can play any PC games or PS2 games that you want and TV to catch the Aerobics OZ style girls that you always seem to start too early to get to see.
When you find that 8000 mp3s are just not enough you go and buy another HDD (you had to anyway cause those last 100000km are probably pushing it on the life of the HDD anyway) and give the old one to some sucker who thinks you are the best.

Wow you could just go on an on about how cool this would be. So you have gotten the whole system worked out and you reckon that with a big buyers discount you could make the whole project for $2000 so you approach Mitsu with your design and they buy the idea off of you for $1M and you are set for life.....

Oh - If you go the Inverter method be careful of the type of Inverter you buy. There are 3 main types..

1) - Square Wave
2) - Modified Sine Wave
3) - True Sine Wave



Actually, "Square Wave" and "Modified Sine Wave" inverters are usually the same. A Modified Sine Wave is in between a Square Wave & a Sine Wave, but an off-the-shelf "Square Wave" inverter would actually be a Modified Sine Wave Inverter. I've been working at Jaycar electronics for over 2 yeras, where we sell these and True Sine Wave inverters, and I've found that required Inverters for laptops & PCs are a bit of a hit & miss - most people can power their laptops with a 300W Modified Sine Wave inverter, but some need a more powerful one (eg: 400W) or use a 300W Pure Sine Wave. Some people even get by powering their laptops with 200W Modified Sine Wave Inverters, but it all depends on the power supply, because the reason why the Modified Inverters aren't as good as the Pure Inverters is because Modified Sine Wave Inverters put a lot more strain on the capacitors in Switchmode power supplies because of higher frequency harmonics.

So basically, a 300W Modified Sine SHOULD be fine, but it depends on the actual ATX power supply.

This thread is like 11 months old... Threadmining = bad..
And welcome to the forums.

off topic but...

Heath... is there anything you don't know about or do as a hobby??? lol


Tim

Just bought this....

http://www.jaycar.com.au/productView.asp?ID=MI5102&keywords=inverter+150w&form=KEYWORD

and doing the same thing, but using a laptop with a broken screen as its tiny (with the broken screen completely removed and running off the vga out) and uses about 65 W max + 3-4 hours off the onboard battery. Also laptops (and especially 2.5" laptop hard drives) are made for a bit of shaking, much more suited to being a carputer... add a cheap usb gps device off ebay, a mobile internet dongle, and a serial interface for evoscan, and you have yourself a good rig for not too much...????

Oh yeah, the inverter cost me $49 due to a stocktake sale Jaycar is having this month...

So far charged my lappy, phone, and took a lamp out with a compact fluro in it.. seems to work a charm. Will make long trips more fun (internet!) and geez camping with 240V lighting will rock....

Going to try and install it below the centre console bin, out of sight, and mount the 240v socket in the back of the console. That way can run a 4 or 6 way power board under the front passenger seat.

Lol threadmine.

Welcome to forums mate, miight be best to just make up a new thread in the car audio section.

If you re interested in carpc's have a read of MitchellO's carputer thread...... lots to learn there