To be used as CD player, the CD-ROM drive doesn't need to be connected to the computer. This way, it is possible to easily transform a CD-ROM drive into a Car CD player. Sounds crazy? Not so. With this tutorial you will be able to have a CD player in your car without spending almost anything.
The CD-ROM drive to be use may be of any type, from the first models ("1x") until the most modern ones ("60x"). The only prerequisite is that the drive needs to have is an earphone plug and volume control. And practically all CD-ROM drives have that.
There are two great advantages in transforming a CD-ROM drive into a Car CD player. First, who will want to break your car window to take CD-ROM drive? And, secondly, since any type of CD-ROM drive can be used, you may take an old drive that is just dusting away in your house (for instance, a 2x drive from an old 386 computer), which brings the cost down to almost nothing.
To install a CD-ROM drive in the car, you will need a female power plug, to be used to fit into CD-ROM drive power plug (that plug can be cut from an old power supply) and a voltage regulating integrated circuit called 7805, that may be easily found at electronic parts stores. You will also have to buy a heat dissipator for the 7805 (sold at the same store).
The car battery is a 12 V one, but the CD-ROM drive needs two voltages to work: 12 V and 5 V. The 7805 circuit is able to convert a 12 V voltage into 5 V (its pin 1 is for the input, its pin 2 is the grounding, and its pin 3 is the 5 V exit). Figure 1 shows the plan for the connection. The grounding pin should be connected to the wires of the plug grounding and the negative pole of the car battery, what is done by simply connecting that pin to the metallic body of the car.
Figure 1: CD-ROM adapter schematics.
All you have to do is to make the connections shown in the above schematics (don't forget to isolate all connections with insulating tape) and you are set: you will have a CD-ROM drive working as CD player in your car.
The audio output will be made using the earphone plug. To listen to a CD, you will have to use earphones. To have the sound come through the speakers of the car, you will have to buy an amplifier with RCA inputs and a stereo P2 (mini jack) x stereo RCA cable (the same type of cable used to connect Discman units to amplifiers). The stereo P2 plug (also known as mini jack), which is the one used for the earphones, should be fit at the earphone output of the CD-ROM drive, while the RCA plugs should be fit at the input of the amplifier. The volume control will be made using the volume control in the CD-ROM drive.
A last warning: in most CD-ROM drives, the reproduction button (play) and the advance button (skip) are on the same key. In other words, to skip a track, all you have to do is to press the play button.