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wong_k

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CD-ROM as car audio player

i have one extra CD-ROM, so i plan to put it into my car as a audio player so i can play any type of audio cd. anyone has any ideal how can i use the car batery as power to supply to the CD-ROM instance of using the normal way by electricity. thank you very much for all your time all the best and have a nice day
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SysExpert
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I am not sure this will work. I would test it in your computer with the data cable disconnected, and just a power cable plugged in.

You need 5 abd 12 Volt supplies for the CDROM drive. I would look for a power supply that offers both at once.

I hope this helps !
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kiranghag

the cdrom can work as long as it has 5/12 volts fed in. also the drive should have headphone connector to get the audio out. some of them don;t have it but they do have a digital 4pin output which is unusable.
just supply the voltage, feed the headphone output thrugh the amplifier to speakers and your'e done. (dont feed them directly to hifi speakers.)
this works as i am using it. just be sure that youre getting 5/12 volts supply and make sure that u dont bump car much as the cdrom drive can be flaky to vibrations
You can get an inverter which plugs into your car's cigarette lighter and puts out 240/110v (depending on where you live...).  Use an inverter with a $5 AT power supply (try a swap meet if you don't have one lying around) to power the CDrom.  You can cut off all the leads you don't need - just be careful to tape up the wire ends well (don't let the red or yellow wires touch anything!).

But (as kiranghag mentioned) I think vibration will be a major problem - most of the CDroms I've seen are prone not only to skipping, but to the CD physically moving around inside the drive when bumped (probably a good way to destroy both the CDrom mechanicals, and your CD).

I suppose you might be able to damp the car's vibrations by somehow suspending the CDrom drive.
d_hall, why would u need 110v inverter when the drive needs only 5 and 12 v dc? 5and 12v dc is what u should get.
I'm assuming since wong_k is asking this Q, he doesn't have the know-how to build hs own dual-voltage power supply.  An inverter and an AT power supply might be cheaper than a commercial dual output power supply.

It'll also save you having to figure out the details of the power requirements for the CDrom - I have four here, and only two detail their power needs.

just a thought: I'm not positive, but I think that it's not the CD-ROM hardware but the software that lets it play audio files other than .cda

If this wasn't the case your everyday cd player would be able to handle all those formats. I might be wrong but I highly doubt you'll be able to play any CDs and if you can it will probably just be .cda files.
There have been articles that may be of use to you if you can find them on a website for Maximum Linux.  Last spring they ran an article on how to set up an entire PC as a Linux powered MP3 player for your car.  It has info on various power connections you would need to make.  Here are a cojuple of websites that go into detail what hardware you may need to make a system work for you in this application.  I don't know if anyone has done it with a Windows based PC yet maybe these articles can shed some light for you.
http://www.qsl.net/ke5fx/cplayer.html
http://www.chaos.org.uk/~altman/mp3mobile/
I don't think you would really be happy hooking up the power and running the CD sound out to the car stereo without the amplification provided by a sound card.  If you are just going to use headphones that's one thing, but to have it ported into your cars sound system with quality sound you would want something other than what a bare CD ROM drive can offer.
In looking at some of the systems on the pages I directed you to these do not follow the same form as they did in the Magazine issue I was talking about.  If you can get your hands on a copy of the Maximum Linux(they are out of business as a magazine)that focused on the MOBILE MP3 players they used rach mount systems rather than mid towers that are suggested on:  http://www.qsl.net/ke5fx/cplayer.html.
They seem to prefer the mini ATX cases for the price.  depending on your budget, I am assuming it is quite low based on what it seems like you are trying to accomplish.  I mean no offense, but to do this right will cost about $500.00 and will not only enable you to use the CD ROM but you can play MP3 tunes from the hard drive.  Having copied my entire collection of CDs to a 10 Gb partition on a 20Gb hard drive I can say that after copying some 250CDs I still barely used any of the available space.  You can really fit a lot of music onto one of these babies!  
Well, it's pretty straightforaward to get it working for regular CD audio, easiest way to do it, is to go to some car accessory shop, buy a dual socket cigar lighter adapter, buy two switchable DC-DC voltage convertors, plug them both in, set one to 5v one to 12v, wire a drive plug on them, plug in your CD, now go get a cassette tape adapter, plug it into the drive headphone socket, and stick the other end in your cassette player, and that's about it, will work great, providing you have the play/skip and stop/eject buttons on the thing to control it., until you go anywhere that is, vibration will be a problem. However you can buy anti vibration platforms to mount regular CD walkman players in cars, you could stick it on one of those, and it should work reasonably well. Those personal Cd players usually have at a least  10 seconds anti shock buffers though, a CD ROM drive has nothing in this line.

regards,

Road Warrior
wong_k,

What you are trying to do is one of those things that is possible in theory but not all that useful in practice.  I think you'll find that the performance of a standard CD-ROM drive, designed for use in a desktop (read that STATIONARY) computer is going to be terrible in your car (read that IN MOTION).  Automotive and portable CD-AUDIO players have two things that computer CD drives don't have:

1) Mechanical shock isolation to shield the optics from vibration and shock.

2) Electronic buffering to keep thje music playing for a few seconds while the drive recovers after hitting a bump or pothole.

Unless you're hoping to just use this when you are parked, I'd suggest you save you time and save up some money and get a real automotive player or get a portable model and wire it into your speakers or something.

By the way, if you REALLY want to continue with this, it's really easy to get the 12V/5V power needed for your drive.  Of course you car already provides the +12V so you just need to generate 5V from this.  The simplest way is with a ZENER DIODE.  I'd suggest a 1N5234 (which will probably cost you less than US$1 and will drop your 12V to close to 5V.  Hook it up like:

12V------|<|------- ~5.5V
(Note the BANDED end of the diode is to the left.)  

If you find that the output of the diode is too much or too variable you could also use a voltage regulator.  The 3-terminal regulators are really easy to use.  The 7805T is also probably under US$1, maybe a bit more at Radio Shack and takes 12V in and puts exactly 5V out.  Hook up is like:

12V------[7805T]-----  5V
GND---------|---------GND

The INPUT of the 7605 is on the left, the output is on the right and the ground is connected at the bottom.  The nice thing about this device is that the output is maintained at 5V through a wide fluctuation of the input voltage.  With the low current needed for a CDROM drive, you will not need to heatsink.
I agree with jhance.

The easiest and cheapest way is to use a 5 volt regulator (7805).

Connect as follows:


 FROM CAR                                     TO CDROM

              FUSE (0.5-1.0A)
 (12v in) O---O><O---O-----------------------O (12v out)
                     |
                     |     5v Regulator
                     |       _______  
                     |   in |       |out
                     O------O  7805 O--------O (5v out)
                            |_______|  
                                O
                                |gnd
                                |
 (Earth) O----------------------O------------O (Earth)

You also get 12volt regulators, but they need a minimum of 15 volts supply to work.
Since the car produces only ~13.38v max, then you have to use power straight from the battery.

Good Luck (don't short any wires and keep a fire extinguisher nearby)
Are you both electricians??
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jhance

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You all are missing something here....getting electricity to the ROM player is not the problem...problem is this

Now, I don't remember which is which of the top of my head, but either home audio, or car audio takes a 4ohm load and the other takes an 8ohm load.

The audio would sound TERRIBLE...don't do it.  go to k-mart and buy a $59.00 CD player and be done with it.  Much easier that way...

Later.
: zxcvzxcv
it is the hardware that makes a cd drive play an audio cd.
if the drive has play and stop button , it can directly play audio tracks, some drives even do it if the head is minorly out of alignment and unable to readd data cds coz audio cds can do with it. also a 52x drive would read a audio cd at 1x speed only.

as far as svibrations are concerned,
you can get SONY DISCMAN or other portable varieties...they can be suffiecent for ur need. they'll also be cheaper as they can run on single power supply (6v i guess). try that
pbessman

In answer to your question, I am a fully qualified Electrical and Electronics Engineer with over 20 years experience in electronics. (won_k apologies for the misaligned diagram, when I drew it in the text box, it used a mono type font and it must have squashed up the spaces).

Huntnman

Without trying to be pedantic, the question was about the electricity and not the impedance.

Anyway, you are stil correct about load balancing here.

The input impedance of a headphone out is usually around 16ohms and the input impedance of an amplifier is usually around 10kohms - 1megohms (quality dependant).

In order to obtain maximum power transfer from CDROM to amp, these must be balanced.
The easiest way to do this is with an impedance matching transformer.

You can obtain these from most suppliers.
instead of doing this all tech stuff, why cant the guy get a portable CD player.....even after doing all the gizmos for a normal CD-rom drive, it would be vulnareble to shocks and would not go long

http://kiran7.freeservers.com
You need a 7805 IC (it has 3 pins), a 100nF capacitor, and a 100uF electrolythic capacitor. Connect pin 1 of IC to 12V and to 100nf capacitor (the other pin of the capacitor goes to ground (-)), pin 2 is ground(-), and pin 3 has 5Volts Pin 3 should be connected to the (+) pin of the 100uF capacitor (the other goes to ground.
The cd rom now has to be connected like: the red wire to the 5V (pin 3 of 7805 IC), black wire to the ground (-), and yellow wire to the 12V (directly to the battery) (see wire colors and orders in your computer).

You can contact me for further details on e-mail : anti@vitacom.ro
well i aggree to the answer, but the problem is the drive would not be able to sustain vibrations, hence i do not recommend normal cdrom unless vibation can be avoided
anti66

You forgot the fuse!!!
You should never connect straight to the battery without a fuse. You could cause a fire if something shorts.
ASPboy

I assumed, that nobody connects this DIRRECTLY to the battery. Any power source inside the car is fused. For example if you use a lighter for a power surce, it is fused.
anti66, a friendly reminder on Q vs. A,

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ComTech
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I will now rejuect the Proposed annswer and return the question to the Active Question Listing.
i have a car cd, with has anti shock buffering, i don't understand why you really want to do this, because

a) if its a normal CDROM, you will not have a skip for rewind function so functions will be limited

b) Even with Antijump holders your still going to get skipping CD's

c) You will require a line in on your car stereo so that it can pick up the sound and amplifiy it through your speakers.

d) With all the cables your going to have from the back to you cigar lighter and then into the back of the Stereo, Well I'll leave that thought up to you, but for what its worth its desirable.

Andy
I don't think you understand my comment. What I am saying is that the CD-ROM will only play normal CDs. Not for example MP3 CDs which I think is what "wong_k" meant when he said:
"i have one extra CD-ROM, so i plan to put it into my car as a audio player so i can play any type of
audio cd"
Unless you want to put the computer in your car too it won't work. Id reccomend getting something like this:

http://www.riohome.com/products/riovolt.htm
or
http://www.riohome.com/products/riocar.htm

It lets you play both .cda (normal audio CDs), MP3 CDs as well as CDs in other popular formats.
>andy
 "creative" people sell cd-rom drives with play, forward, reverse and stop/eject buttons, they also give you a sleek infraread remote control. in india the brand is Infra.

most seem to agree against using a normal CDROM drive, for the obvious reasons.

well, i am advertising SONY ( or other people) but wise choice could be getting a portable CD-player, it can not only be played in car, but elsewhere too. such player may be designed considering the shock issue...so think on it.
wong_k? Are you there?
Don't you hate it when that happens???
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ASKER

thank you very much for your time, keep the good  job guy...
ComTech
ComTech here and gone.  What a messed up answer to accept with no explanation.
pbessman,

The notification email I received says:

"Congratulations! Your proposed answer has been accepted by wong_k!"

So if you have a problem with which comment was accepted, please take it up with wong_k, not ComTech.

I believe ComTech merely changed the grade from:

"You've earned 200 Expert points and have been rewarded with a grade of C."

to an A.  I suspect that this was done because the "C" grade is ALWAYS undeserved in the case of a COMMENT accepted as an answer.
wong_K, please come back and explain your acceptance of the answer you chose, I do not believe it is correct.  This can be easily remedied if someone else was of more help.

BTW-the points were 100 just for the record.

pbessman, would you like to make a case as to who, in your opinion as to who had the right answer?

Thanks all,
ComTech
Community Support

Ps. Came to look at the Q yesterday and didn't have time to look this over.
I'll make a case that my comment from:

Date: 08/27/2001 04:06AM PST

is the earliest reasonable answer.  It could be that wong_k liked this comment but accepted another of my comments by accident.

I note that pbessman had earlier comments and while that are reasonable comments, they don not specifically answer the original question.  While pointing out that what wong_k is attempting is not exactly a useful thing, pbessman did not explain HOW to do it.

I pointed out some drawbacks to this approach but also told him how to accomplish it.  Perhaps he just want to do it as an experiment or for some learning exercise.  Not all things we do need to be practical.
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i am sorry for the point, but i already test it and it can work. thank you again for all your support. have a nice day