| ACD-ROM drive can be used as a stand-alone
unit for playing digi- tal audio CDs without interfacing with a computer. The stereo
output of CD player available at the audio jack can be amplified using audio input
facility which is normally available on a tape deck/tape recorder or a stereo amplifier.
Audio socket on front/rear of the CD-ROM drive is capable of driving headphones or
speakers of less than 500 mW. Proper stereo jacks for interconnection between CD-ROM drive
and tape deck are available from computer/tape recorder spares vendors. The principle of
operation is illustrated here with the help of block diagram. The 4-pin power supply
socket available at the rear of a CD-ROM player is meant for +5V, ground (two middle pins)
and +12V inputs. The power supply can be easily derived using a conventional power supply
circuit as shown in the figure. If you have an external CD-ROM drive, it can be simply
plugged into the mains since it has self-contained power supply circuit inside. While
there may be minor differences amongst the available CD-ROM drives’ external
controls, a typical drive’s controls are shown in the figure on top. Please ensure
that a proper power supply connector available from computer spare parts vendor is used
for connection to CD-ROM drive. To identify +5V and +12V pins on the drive connector,
please note that in the computer +12V is routed using a yellow wire and for +5V a red wire
is used, while for ground black wires are used with the supply connector. Once the power
supply has been connected correctly, you will notice that LED indicator on the drive
starts flashing. Now the digital audio CD can be loaded after pushing the eject button. A
second push of the same button causes retraction of CD carriage into the drive. One can
change the track (song) on the CD using play switch on the CD-ROM drive. |
|
