How to Make a Low-power Power Supply Unit From Discarded DVD Player

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Introduction: How to Make a Low-power Power Supply Unit From Discarded DVD Player

Have had enough of taping together batteries or making tagliatelli of wires to provide some volts for your electronic project? Yes you have !

Instead of buying a new PSU (power supply unit) why not use a power circuit board from discarded A/V equipment or some other home appliance. Many audiovisual devices in your home have built-in power circuit boards providing juice for the inner electronics operating at 3.3V, 5V, 10V, 12V et cetera. Although they often provide low current they could be well suited for your electronic projects such as LED lights, small motors, and other low power stuff.

I hardly throw away electronic appliances so I had a look in my pile of A/V equipment for what might be suitable as DIY power supply. Some other equipment I came across even had 1.2V, 7.5V, 9V, and 15V too, again, all at once. I chose to use a low-end DVD player having a nice little power board providing me 3.3, 5 and 12 Volts.

Here is how I did the whole thing.

Tools needed:

· the obvious screwdrivers, perhaps also Torx
· screws, brackets, encasing of any kind of your liking
· multimeter
· cutter and pliers
· soldering iron
· some wires and other small conductors to serve as bridge, manifold or DIY connections
· a discarded appliance like DVD player, VCR, CD player or anything you'd like to try out for donor

NOTE of CAUTION:decide for yourself what materials and components you are going to use whilst being realistic and considerate of risks these kind of project may bring. Always keep safety in consideration, especially when other people than yourself use your creation or are near it.

Step 1: Empty, Unplug and Open the Casing

Let's presume you selected a discarded DVD player for this project, as I did too.

Check to make sure there are no DVDs or CDs left in the tray. Switch it on, then unplug it from the power outlet. This way you discharge capacitors and prevent a nasty bite in the fingers. At any and all case, don’t touch the electronic components or wires unless you’re absolutely sure all components have discharged.

So now, unscrew the casing (you probably couldn’t wait and already did it)

Take a picture of the inside for your reference. Locate the power PCB (‘printed circuit board’). Typically this is a separate PCB at which the power cord leads to. I marked it with an ellipse, see photo. Some power cords use connectors, others are soldered. If there is no separate power PCB, yer unlucky. Or, find a bigger casing to accomodate the entire circuitboard, but you might then as well keep the entire DVD device and have the wires coming out of the DVD tray slot ;-)

Note: the photos in steps 1 and 2 of this Instructable are from an HD recorder, but I used a DVD player. The principle and work approaches are the same. I built this project some time before I made this Instructable therefore I couldn't make photos from the original DVD player anymore.

Step 2: Disconnect and Unscrew

Disconnect the small wires to and from the PCB and other components such as the DVD tray, front display et cetera. Usually they are attached with flatcable connectors. Keep the screws for later or other use. Some connectors you can unplug on one end by using a small screwdriver and carefully pry between the 2 tiny plastic parts of the conncector or pull with modest sideways rocking, not tilting the connector. The photo shows I pull by the wires, which is not the Official Best of All Methods, but gripping the plastic connector with my fingers seldomly worked for me .
To make removal of the PCB board a little easier I removed all cables, including the ones attached to the PCB itself. Just make sure you understand or remember what wiring is relevant for you.
And don't just yank it out. Instead, cut the wires if they are soldered but make sure to leave the wires on the power PCB end.

Unscrew the power PCB and try to keep the power cord attached when it is soldered. You’ll need it powered, not?

Most often, the power PCB has voltages printed in tiny letters following the order of the tiny wires. Write them down, they are your future power leads. Note that many power supplies also have MINUS volt connections, meaning that combined with GND (ground), it gives negative volt. If you reverse polarity, you’ll have PLUS. Or, you could make a combination of, say, -12V and +12V and so have 24 Volts, but I am not sure if that will be a steady supply since you have no GND then.

Step 3: Encase It and Present Power

Find a non-conducting encasing which is sturdy enough for handling and has the right properties and dimensions to fit, mount and screw the PCB in AND to put in some additional wiring for your DIY connectors or wiring coming out. I used a wooden box holding a long gone mini bottle of booz.

You may want to have some room in your encasing, perhaps you want to add another PCB or even a dissassembled power adaptor from phone, laptop or whatelse (I'll make an Instructable of that when I get to it)

Be creative and resourceful to mount the PCB in the case and have the power cord neatly going out. Beware to not screw through the bottom or sides because you want to have the PCB isolated.

Tip: if you drill hole in Plexiglas, PVC or PET, you'll notice that often the material melts due to the friction and wraps around your drill bit. The trick is to drill a short while (say 2 seconds) then wait for the molten plastic to harden, then continue, et cetera.

Think of a way you like to have your power presented on the outside. I chose to use a breadboard (often used for Arduino controller boards) on a transparent top over the box.

Make it so !

Qwertypat, february 3rd, 2016

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22 Comments

Ive been using a power supply from a DVD player for many years. Its really handy for small electronics projects. Im often needing 5v or 12v for LED projects, and this is a good sized power supply for essentially free.
The DVD players also have neat displays that you may be able to reuse, mine has a VFD display, which is really cool, but I never figured out how to operate it.
DVD players also have very nice track mechanism for moving the head across the disk, but I havnt figure out any way to use it. it might make a nice tiny laser table or something similar.

Hi HippyNerd, thanks, that is good to hear - we can now consider it as Proven Technology! About the disc tray, me too have been thinking about how to use it. The motor that moves the laser/lens carriage back and forth are tiny motors often connected with 'film-wire' to a controller. The motor can easily be operated by connecting + and -, but to operate it in a controlled manner with accurate positioning I suppose it requires sensing the carriageposition is at any given moment and control motormovement accordingly. Let me know if you come across a nice idea

About the display: yes they are cool, I haven't yet managed to DIY a nice project with it. Many multifunction displays (certainly matrix displays) need some sort of display controller or 'driver'. I imagine that if you'd open a working device and measure at what pins the displays needs its GND and power (say 5Volt), you could poke are around with a 5V and see if you can light the individual segments of the display, to explore the working of it.

cheers

qp

I havnt messed around with the VFD display, I wanted to make it work, but i havnt much clue how to go about it. If I had a data sheet for the part, that would help.
The only thing Ive come up with for the mechanism is a very small laser cutter table. Even a small one would be nice for making small objects, maybe even make business cards or something useful. It seems like a very precise mechanism that could be very useful, if I knew what to do with it.
I like the way the VFD display looks, and I would like to make it do what I want, I could rebuild the DVD player to just be a neat clock display, but it does other things based on time or other input.

That bring up another use, the case for the DVD player can be used for housing your electronic or art projects.
The power supply however has proved to be very useful, I used to use it almost every day.
Here is a horrible video that I made about it a few years ago. Sorry about the video quality.
https://www.youtube.com/watch?v=KAY-7dzLJH8

I found something. The VFD (Vacuum Fluorescent Display for new readers) below came from an Aristona / Philips DVD player, type MDV434 so I searched for 'Service Manual MDV434' and found detailed schematics. The tiny front circuitboard with the VFD connects to the mainboard using clocksignals and datasignals, this is complicated to hook up to, I suppose.

However, the VFD controller type PT6312, as seen below, drives each individual segment and is located on the front circuitboard itself. See photos.

Maybe this is a starting point to continue your search. Other interesting sources are: lcdsmartie.sourceforge.net and noritake-itron.com

frankly said, I will not pursue this further at the moment - it's quite time and brain consuming..

Yeah, I know what you mean, you could spend weeks fussing with it, and get nowhere. That does lok like a real nice display, It loks like it has 7 14-segment displays, Those are nice for doing text, and fun animations.
I would be interested in seeing the results if you do ever get around to it.

This is a great article. It would be nice to see how to hook this up to a few LEDS for welding in dark areas. Most of my plastic flashlights eventually melt due to hi hear while welding. I need to make my own flashlight that will use the replaceable welding shields for a longer life.

Hi Merkeligur, thanks.Intesting idea you have, I think.

You mean welding like MIG/MAG and electric arc welding? That creates a lot of heat indeed and I have no experience how to prevent overheating a near/close lightsource. Perhaps you can use a piece of a glass from heat resistant glass, like an oven dish or maybe even from a car's halogen headlight and use it as a shield?

cheers, qwertypat

the capacitors in those old devices are dried out and out of spec. especially if they were made in china

Hi Mike, yes indeed, many modern devices have components of questionable quality and it doesn't get better over time. The DVD player I used had a mechanical defect and the power circuit worked still fine (no clue how long it lasts though)

Neverthless, re-using good parts and components is a way to give it a second life with fun in the first place. ;-)

cheers, qp