use ur old computer CDdrive to enjoy audio CDs in your car

[samehham]

use ur psu to power other things

I'd like to share this with you
I used an old computer cddrive with some simple modifications to make my car cassete operate CDs, and here are the details:
computer cddrive requires two voltages supplies one is +5v , +12v
your car has only 12v , to get the +5 u just use 1 amp +5v regulator like 7805
the other issue is for audio interface , it is rather easy:
at the back of your cd u will find the analoge audio output which is 4pin connector, the middle two are audio ground and the other two are the lift and right channels, connect these two to audio volume of your car cassete and u have done.
at this point it is fine I could run audio CDs only but unfortunataly !!!! I couldnot run mp3 CDs
I'd like to hear from any expert on how to run mp3 CDs
welcome to any Ideas and sujestions

 

[Pazam]

how to use you computer cd-rom in a car

Dear samehham,

You can't.

MP3 playing needs processing your CD drive can not do.

I don't think there are CD drives for PC that can play MP3, since most of them are connected to a PC.
As prices are getting low every day, I don't think anyone will bother adding MP3 capabilities to these kind of drives.

One last thing - You should check the drive's voltage specifications. Car voltage can be between 8V and 14V. It also include a lot of noise and spikes.

Good luck,

Pazam

 

[samehham]

Re: use ur old computer CDdrive to enjoy audio CDs in your

Dear Bazam, I appreciate ur response and the info,
but I'd like to say That it has been running for several months without a problem , except operating mp3 CDs

 

[vfone]

Re: use ur old computer CDdrive to enjoy audio CDs in your

Your idea would be limited for playing CD format. To play MP3 using a computer CD drive, you need an Operating System and a dedicated software.
regards

 

[FoxyRick]

Re: use ur old computer CDdrive to enjoy audio CDs in your

You might be interested in this month's (April) Elektor magazine. It has a project using a PIC16F877 to control a CD-ROM for audio use, allowing track selection - something you can't usually do with the CD-ROM alone (unless you have a very old one with the buttons).

It won't play MP3 though...

Cheers,
FoxyRick.

 

[nikifena]

Re: use ur old computer CDdrive to enjoy audio CDs in your

try this
hxxp://www.mp3projects.com/
there is a lot of mp3 players (with CD-roms too)

if you like only audioCd player from old Cdrom (without play button)
see this topick
hxxp://diyaudio.com/forums/showthread.php?s=93b0f5059eca45b925f0597d797b9a81&threadid=17910&highlight=


Good Luck

 

[maro]

Re: use ur old computer CDdrive to enjoy audio CDs in your

I've mounted a Cd-rom drive in my car and it's working perfect, well almost. Does anyone knows how to eliminate a noise that CD-rom creates ?
I can hear electromotors through speakers.

 

[pisoiu]

Re: use ur old computer CDdrive to enjoy audio CDs in your

The noise is not created by cdrom, it is created by the engine, passed to cdrom through power lines (computer cdrom is not designed to work in automotive environment and it does not have proper noise rejection filters on power lines) and amplified by power amplifier. You will have to isolate 12 volt line that inputs into cdrom by a LC filter. If the power amplifier is a part of the car (ex. line input in car's audio system), then it has filters on power input. If the power amplifier is also installed by you and it is not designed for automotive use, you'll have to isolate it as well.

/pisoiu

 

[maro]

Re: use ur old computer CDdrive to enjoy audio CDs in your

I'm aware of RFI that car engine produces and I do have an LC filter for that but this what I hear is defenitely a CD-rom electromotors. Amp is not home made, it's a car amplifier I bought.

 

[pisoiu]

Re: use ur old computer CDdrive to enjoy audio CDs in your

Hmmm..very strange...I also used computer cdroms as audio sources and I never heard noises produced by cdrom motors. If you are right, then the noises should be present when the car's engine is off. In this case, another possibility is that the noise is induced in ground connections. Try to bond a thick and short ground connection between cdrom case and the case of the power amplifier.

/pisoiu

 

[maro]

Re: use ur old computer CDdrive to enjoy audio CDs in your

I know it's very strange and I don't know what else I didn't try to eliminate this. Let me tell you some other things. When I connect hearphones there is no noise at all, I also connect it to amp (computer loudspeakers) which was not powered by a car battery and also there was no noise, and also tried to connect CD-rom to computer power suplly and there was no noise. When I disconnect CD-rom and amp I can still hear it but less. Another interesting thing is than ground output wire from CD-rom is not needed, I can just connect left and right channel to amp and sound is there. I was thinking of putting LC filter before CD-rom suplly circuit and leave amp without filter since you said that amp already has it. I used 7805 to get +5 V for CD-rom. Both CD-rom and amp chasis are already earthed. Since you did same thing can you email me schematic how you connected all this stuff together, maybe I made some stupid error while connecting. (mpolonijo83@yahoo.com)

 

[pisoiu]

Re: use ur old computer CDdrive to enjoy audio CDs in your

I attached a schematic. In my opinion that is how it should be. But there are some comments. One thing which is not quite allright is the main power supply. A computer cdrom needs 12v+/- 5%. The car's battery may in some cases go over 12+5%. The thick connections from sch should be as short as possible, and made with thick wires (at least 1mm diameter). Caps should be low esr, and the inductor made also with thick wire over a ferrite ring. Also, this is important, in this schematic, the amplifier should not have an included noise filter ! If the amplifier have filter with inductances on both lines (12 and gnd), then the input ground which you use to connect to the power supply and also with cdrom ground is not identical with internal amplifier ground which eventually is connected on the other side to the input ground through the audio cable. This may be your noise source. If the amplifier have included filter, then you should take for cdrom both gound and 12v from the output of that filter, and take care to isolate cdrom chasis from the car's metalic parts.

/pisoiu

 

[maro]

Re: use ur old computer CDdrive to enjoy audio CDs in your

OK. I'll try with this you sent me and let you know. Thanks..........
O yes, one more thing ; do you think I should use some 12 V regulator to get those 12 V +5% cos I had no problem with that so far (1 month) ?

 

[asit]

You can not use 7812 type regulator on for 12 volt supply. They need atleast 2.2 volt difference betbeen input and output. this is fine if your battery is charged or is chargine which is about 14.2~14.4 volts. but if your battery is discharded below 14.2 the 12 volt out will also drop.

Secondly, it seems you are not using Ground from the 4 pin cd-rom analog audio out connector. Connect a shieled cable using shield as ground at both ends and core wires as Left/Right channels.

 

[Shoaib]

1: cd-rom is not effeced by supplying 14.4volt
2: use 1F or atleast 1mF capacitor if u want to isolate noise
3: 7805 will heat up and cant provide 1amp constant current. if the thermal switch cut out the output of 7805 then .....
4: there is a kit which converts audio cd player to mp3 palyer, but MP3 player is just a piece of crap in cars.

 

[maro]

Re: use ur old computer CDdrive to enjoy audio CDs in your

I've mounted 7805 regulator to an old processor cooler (Pentium I) and it's not warming at all, but I did have problems with that thermal shut down befor that. I'll try with that shielded cable ;

 

[metal]

Re: use ur old computer CDdrive to enjoy audio CDs in your

Hello

Any one has the article of Elektor Electronics for using PIC16F877 to control the CD-ROM.

Regards

 

[eddyboy]

Re: use ur old computer CDdrive to enjoy audio CDs in your

get some ferrite rings and wrap each lead through and around the rings several times....
you will need to do this with the +12v, -12v, and the audio leads. place the ferrite rings as close to the cd drive as possible.

 

[adidex]

Re: use ur old computer CDdrive to enjoy audio CDs in your

I know it's very strange and I don't know what else I didn't try to eliminate this. Let me tell you some other things. When I connect hearphones there is no noise at all, I also connect it to amp (computer loudspeakers) which was not powered by a car battery and also there was no noise, and also tried to connect CD-rom to computer power suplly and there was no noise. When I disconnect CD-rom and amp I can still hear it but less. Another interesting thing is than ground output wire from CD-rom is not needed, I can just connect left and right channel to amp and sound is there.

The noise comes from the potential difference between the CDRom and the power amplifier. The current consumption of the CDRom generates an potential difference between the ground connection of the CDRom and amplifier (the cdrom motors have the highest power consumption ...).
That;s why you can her the sound clear on the headphones.
You can hear the sound in the amplifier without connecting the ground output wire becouse the amplifier and the CDRom share the same ground level anyway through the power supply.
The sollution is to reduce the pottential difference between the ground of the CDRom and the ground of the amplifier. I would recommend to conect their grounds through a short and thick cable (3-4 mm diameter), and the problem should dissapear.

Adi

Added after 3 minutes:


One more thing, if you place ferrite beads, you should connect them between power supply and the supply of the cdrom and amplifier.
there must be no ferrite beads between the ground of the amplifier and the ground of the cdrom