How to make a simple CDROM Power Adapter

This is a quick and simple project that shows you how to create a power adapter for your CDROM to play CDs without the use of a computer or its bulky PSU. It requires minimal components and can be done in a relatively short time.

Introduction

I did some research on the internet about stand alone CDROM players and found that most of them were powered from the same bulky PSU that came from the computers. There were also some that had a smaller custom power supply that were less cumbersome and more attractive. I had the idea to build my own custom adapter based on the parts I had and the compatibility of the items.

To power the custom adapter, I chose to use a laptop charger/power supply that had a power rating greater than the power consumption of the CDROM. In my case I had a 24V 24Watts power supply and a 18V 24Watts power supply. Since the CDROM required both 5V and 12V to operate it, a voltage regulator of the corresponding voltages will be required. From my knowledge of voltage regulators, I know that to dissipate less waste heat from the IC, the input voltage show be around 2V above the output voltage in order to work properly. So with this in mind, using the 18V power supply was the better choice.

The 18V power supply rating of 24Watts was just above the power consumption of the CDROM which was:

5V * 1.0A = 5W

+ 12V * 1.5A = 18W

Total of 23Watts

With a adequate heatsink, the 1A voltage regulators I was planning to use could handle up to 1.5A which was the exact amperage the CDROM needed on the 12V input. You can see a sample datasheet here.

If your CDROM consumes more that 1.5A on either line, you should add a current booster to the circuit.

The setup I have was cutting it real close on the margin of maximum power output of the components.

Here is the simple circuit schematic that was need for the power supply. I used the same heatsink for both of the ICs.

Here's a video of the initial testing of the CDROM

I used my Case/Safe to do this project.

Things you need

Here is a short list of the things you need:

  • 7805 series voltage regulator
  • 7812 series voltage regulator
  • adequately sized heatsink(s)
  • small perforated breadboard
  • heatsink compound
  • power jack connector
  • a short section of a molex connector wire

If you need more current on the output, refer to this page for the additional components.

Here's two snapshots of the components I used in this project.

Apply the heat compound/ thermal paste to the ICs and mount it to the heatsink.

Insert the assembly at a suitable location on the breadboard and punch slots on the board to mount the power jack connector.

Secure the connector to the board and solder the all the leads to the breadboard. I built this power adapter using to parts I got from my collection as shown in the background.

You need to make slightly bigger holes in the board to solder the output wires. Here's a another snapshot of me tinning the wires to be soldered to the breadboard.

Wire the breadboard using the schematic above. Please note that you cannot take the input voltage of the 5V regulator from the 12V regulator output. You could theoretically, but that would require a current booster on the 12V regulator. It is best to take the power directly from the power jack as shown in the photo above (red wire).

Here's a close up of the wiring.

To insulate the underside of the circuit board, I screwed a plastic cover from a small plastic box to act as a base.

This is the final result of the project. A small and simple power supply adapter for a typical CDROM.

Here's the complete original video

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