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Discussion Starter · #1 ·
building a car pc and i got a few questions:

1) anyone know of any good lcds that are thin. i need 2 rediculously thin lcds that have good quality

2) anyone know about power supply related things? i need some adapter that allows me to charge a 2nd car battery that i'll be storing in the trunk to power the comp. also, is there any better way of powering the comp than using a 12vdc car battery w/ a 300 watt power inverter to go to 120 vac and then using the comps power supply to go back down to 12vdc. im learnin stuff daily in my electrical engineering classes, but i dont know enuff yet for it.

3) sound cards...any recommendations? sound quality is of utmost importance

4) graphics cards...i need something with rca or svideo outs, altho im wondering whether it'd be better to get something w/ a digital signal and use some sort of laptop screen interface (therefore gettin better quality)

also. since i'll be recording music videos n such so i can play em in the car, anyone got any recommendations on affordable capture cards?
 

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power supply

finally a question about something i sorta know.


well, first off, you will want a battery mounted somewhere in the vehicle, trunk like you said would be fine. you will want to use a 2 amp filtered charger running from the cars main electrical system and set it so it runs all the time, the idea is to never let your pc's battery drop below 60%

second, i am not sure a 300 watt inverter is going to be sufficient. most inverters are rated at their "peak" output. i dont know what type of power supply your pc has, but im hoping it is about 300 watts. and your lcd panels are going to require a tiny bit of wattage also, i dont know for sure, but id say about 15 watts. so i would say you need a 500 watt peak/ 400 watt continuous inverter at the bare minimum. try to keep it like this:

take your normal power consumption (plug the machine in to a
socket and amp test it, and then use ohms law to get wattage)
for example:
power consumption = 350 watts
add 30 %
350 + 30% = 455 watts
this means that you need a peak of AT LEAST 455 watts.

and try to buy a sorta big battery for the pc. not an rv or marine, but a large car battery. use the book, look up what a 1979 lincoln continental with power everything would use, and buy that one.
or buy a spira-cell from optima, but those are around 140 bucks and a 60 dollar battery would be fine here.

above all, try to make sure to keep the battery mostly full, and dont run an inverter that isnt strong enough.

~BoB~
 

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also might i suggest

you could also just use a laptop, and most of them will run off of 12v dc. then you could run an intricate mess of usb cables to all the devices you want to run, and if you integrate the pc like i think you want to do, a laptop could drive what you are wanting without much watt load. eliminating the need for an inverter, and second battery. but you would still want to use a filter. the alternator produces nasty static, and pc's are fragile little babies.

the other idea would be cheaper....


~BoB~
 

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Here's my suggestion: Since you're in an electrical engineering class, you should be able to research it easily, and it'd be good practice. Just run the 12V directly in and have a 5V limiter in parallel. You'll want filtering to eliminate noise, but you should be able to build a plenty strong enough power supply off of a few transistors, some zener diodes, and stuff. The only issue here is heat and impedence of your supply. It'd be good practice.
 

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well

well, if a dc power supply is what you are after....

they make power supplies for a pc that connect to a car system.

and as far as making your own, that would work fine too, but the 12v in for the pc cannot be run straight in, unless your extra battery is being charged by a special charger running at 12v. if it is being charged by the cars' normal system, then the battery will actually be running between 14.8 and 16.2 volts, so you dont want to run that power straight into your machine. filter it all... a voltage of about 12.2 would be fine...

but really, go and buy an RV computer power supply....
it will run off of 12volts, and you wont even know it...

but what about your screens?

hmm, i think they prolly make 12v screens too..

~BoB~
 

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Most 12V devices work fine off of 14-16 volts anyway, so that isn't a major problem. As far as a display, you might wanna check www.ramseyelectronics.com (or some variation). Been awhile since I accessed that site, so it may be diferent from what I put here.
 

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I have an idea: I think most LCDs run off of lower voltages like 12V, so you might wanna try a regular PC display and hook the car's electrical system to it appropriately instead of using the 120V power supply that comes with it. They usually tell you what voltage they run at on the case. Also, where have you thought about putting the LCD? Have you thought about maybe a small LCD in the floorboard sorta under your seat? Probably directly under your steering wheel.:D
 

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Re: well

bob vila said:
well, if a dc power supply is what you are after....

they make power supplies for a pc that connect to a car system.

and as far as making your own, that would work fine too, but the 12v in for the pc cannot be run straight in, unless your extra battery is being charged by a special charger running at 12v. if it is being charged by the cars' normal system, then the battery will actually be running between 14.8 and 16.2 volts, so you dont want to run that power straight into your machine. filter it all... a voltage of about 12.2 would be fine...

but really, go and buy an RV computer power supply....
it will run off of 12volts, and you wont even know it...

but what about your screens?

hmm, i think they prolly make 12v screens too..

~BoB~
Here's a good place to start!
http://www.xpcgear.com/powersupply.html
 

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pricey

here is a link that sells a dc to dc power supply for computers. but look at the prices.... OMFG

Power Supplies


wow, thats a little too much, id try a filter to the battery instead of finding an rv power supply or an inverter.

but i will say this...

you wont ever catch me running my hard disks at more than 13 volts or so. and i am not sure that the 12 volt areas on my motherboard would like it so much either...

but a 400 watt 12 to 110 inverter is only about 100 bucks...


either way...
good luck.
~BoB~
 

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Discussion Starter · #11 ·
thanx a million for all this badass info. for clarification, im also referring to color lcds (gonna be playin divx/dvds). i found out about the cajun project and more amusingly, the modchip'd xbox (omg, that'd be so funny to be runnin an xbox media system in my car)

the bottom line is that i havent set my mind on anything except the functionality. once i get the hardware aspect of the system done, the software will be a joke.
 

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Lectraplayer said:
Here's my suggestion: Since you're in an electrical engineering class, you should be able to research it easily, and it'd be good practice. Just run the 12V directly in and have a 5V limiter in parallel. You'll want filtering to eliminate noise, but you should be able to build a plenty strong enough power supply off of a few transistors, some zener diodes, and stuff. The only issue here is heat and impedence of your supply. It'd be good practice.
Having a little electrical background myself, I would go this route. Don't forget 3.3v tho!

I'll check around and see if anyone I know has a schematic allready drawn up-


out
 

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you can follow up with it anyways, Jamman....Im sure people come back....and variety is the spice of life...or something....I still wanna see what schematics you come up with....

P.S. have a question for ya... I got this EL wire that I want to put in my case. I've already added a molex connector (btw, the wire is for the car), and its working fine when I plug it in, but the little transformer makes a helluva lot of noise. Is there anything I can do about it ? TIA
 

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hmm

well, i am not sure what an EL wire is, as i have said before the abbreiviatoins throw me off. but one way i know of to filter noise out of a signal wire is to either put a resistor (like something close to 47k ohms) between the two wires, sorta shorting them, but not quite....

and another way is to put a capacitor (300 uf or so) into the end of the circut, usualy facing backwards on the negative branch.

they also have some 300 wrap to 299 wrap filters that you can put inline, similar to the ones used for PC's or car stereo's. this is basically a little transformer that breaks up the harmonics from the voltage signal.

thats if its noise from your engine you heard on your system.......

otherwise, perhaps you need to check your whole length of the EL wire, maybe it needs to be a 100% sealed coaxial wire. i know with some tihngs, the wires will act as an antennae if the positive (signal) wire is not fully shielded by the negative (ground) wire. if this is the case, then you will maybe need to get different wire and connections.

but i would think you are talking about hearing the ignition hum in the system when you plug in this EL wire. and not about signals from the atmosphere saturating your wire...

~BoB~
 

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bob vila, thanx for the tips !!!

Im actually talking about putting EL (electro-luminescent) wire that is usually made for the car, in your PC case. This wire look just like a regular piece of wire but it lights up...I definitely have experience with the annoying "speaker hum" from installing amps in my car, and I think its the same thing with what I have now..this little setup cost me $15 off the shelf , minus my molex connector, I figured something would be crappy...I think I might go with the resistor or capacitor idea....thanx again, and keep the good tips coming !!! :D
 
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