anyone have pc's in there cars ?

[imagex]

12 volt is mainly used for your drive motors, hard drive & cdrom.

[MadHacker]

Originally Posted by jaydee116

Fans and the 12V also is the source of the the other voltages if I remember correctly. I think the 12V is broken down into the other rails. That makes a smoother current or something. Been a while so I may be wrong.....

Originally Posted by imagex

12 volt is mainly used for your drive motors, hard drive & cdrom.

But what is the -12 Volts used for? as in negative voltage... :shrug:
is there anything that actualy uses it?

[Groth]

-12 was used by ISA sound cards, don't know of anything that still uses it. -5 is still used by serial ports.

[MadHacker]

Originally Posted by Groth

-12 was used by ISA sound cards, don't know of anything that still uses it. -5 is still used by serial ports.

so for a new system to have in a car all you would realy need is 17 volts, +12 to -5
and if you don't need the cerial port all you would need is 15.3 volts, +12 to -3.3

[Groth]

-3.3 ?? Never heard of that one.

Yup, you should be able to do it with just positive voltages for a legacy free board. And the center tap idea to get the negative voltages is overkill - easier and cheaper to use a small charge-pump to if you need the small amounts of negative voltages.

[leejsmith]

i have an update on my car system. it's still work in progress and i think i am gong to change the pc but it all works.

7inch lilliput touchscreen
haicom serial gps (same one from the hp system i used at the start of ths thread)

HP E-PC e-vectra p2760a that work gave me to use on the project.
This is a small form factor pc that uses a 19v dc power block and i use a laptop car power block that also gives me 19v at 5000ma the pc only needs 3160ma.
The only thing i changed is the slim cd-rom for a dvd-rom.

A customer at work made a blanking plate to go in place of my dual din car stereo and i used velcro to attach the screen to it so i can remove it. as the dash is silver and the screen is too it looks ok.

For mouse if i need it i use a shuttle remote that came with my SFF XPC.

It's running xp with mediacar as an interface. Navigator gps software which is not the best but was only £35 and gives full voice navigation.

Media car works with a dlnk usb radio but i had trouble getting one so i used a wintv usb. This will also let me use the tv capture for rear parking camera or watching tv. I had to use radiator to get the wintv usb radio working in media car.

The last part was audio and i have a small 4x30w or 2x60w amp.

Now this all works apart from loads of engine noise on the audio side.
I dont know if it's from the power to the pc or the amp it's self but i have very little time at the moment.

I am still thinking of getting a via itx board and the opus psu instead of the hp e-pc. The itx board will fit inside the dual stereo's old home to make a very tidy installation.

[imagex]

hey leejsmith, I also had alot of problems at first with noise, if you use a walkman instead of your pc you can see if its in your amps or the pc. I had some of both" alt noise and harddrive/ cdrom noise" , I ran 4 gage wire to the rear where my amps are "about 1500 watts " and I did both + and - lines and used a 1 farad cap that helps to filter noise also, then I used a ground loop isolator on my highs, on the pc side I use a soundblaster mp3 pro with usb run back to the amps, this way theres less audio cable to pick up any noise, one more thing that helps is I set my pc sound level to max and then set my amp gain to were its just below distorting " the higher your amp gain the more the inputs on your amp act like a mic. hope this helps . as for radio support in the software were working on a usb tuner now also XM radio too. We have so many things to do as add-on's we'll be busy for the next 5 years, lol

[bigben2k]

Putting a PC in a car is an idea I've toyed with for years, but I could never get passed the power issue.

How do you do it? Do you have to add an alternator and/or battery?

[leejsmith]

Originally Posted by imagex

hey leejsmith, I also had alot of problems at first with noise, if you use a walkman instead of your pc you can see if its in your amps or the pc. I had some of both" alt noise and harddrive/ cdrom noise" , I ran 4 gage wire to the rear where my amps are "about 1500 watts " and I did both + and - lines and used a 1 farad cap that helps to filter noise also, then I used a ground loop isolator on my highs, on the pc side I use a soundblaster mp3 pro with usb run back to the amps, this way theres less audio cable to pick up any noise, one more thing that helps is I set my pc sound level to max and then set my amp gain to were its just below distorting " the higher your amp gain the more the inputs on your amp act like a mic. hope this helps . as for radio support in the software were working on a usb tuner now also XM radio too. We have so many things to do as add-on's we'll be busy for the next 5 years, lol

thanks for the sound tips.
I was thinking of using a sound proccessor from the pc digital output but it might be a little over my budget. the usb soundblaster is a good idea.

i dont think the amp i used to test is very good that could be my problem but i will test it with a walkman to see.

[imagex]

ya the soundblaster mp3 is only abot $40 not bad at all.

To bigben: we use pc's that are dc micro atx, others do still go about it the hard way using inverters to power full size atx mobo, check my site to see some specs " we dont sell to the puplic yet still prototyping more software and hardware" http://hybrid-mobile.com

[bigben2k]

Yeah, an inverter is a no-no: it's just too inefficient. A microATX would be ideal, I was considering the same, even one using the Epia processor, if necessary.

But how do you power it? If you use a direct line to the battery, you'll have maybe 14 volts, with a lot of bad nasty noise.

[Sandman001]

USB and ethernet use -12V for something. I know they used to anyway. It's just a signal, ntohing big though.