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

Comments

author
HippyNerd made it!(author)2016-02-29

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.

author
Qwertypat made it!(author)2016-03-03

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

author
HippyNerd made it!(author)2016-03-03

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

author
Qwertypat made it!(author)2016-03-03

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

MVD434 display VFD-54.PNGMVD434 display  controller PT6312.PNGaristona MVD434 display.jpg
author
Qwertypat made it!(author)2016-03-03

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

author
HippyNerd made it!(author)2016-03-03

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.

author
merkilegur made it!(author)2016-02-29

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.

author
Qwertypat made it!(author)2016-03-03

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

author
MikeA95 made it!(author)2016-02-29

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

author
Qwertypat made it!(author)2016-02-29

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

author
Mark+42 made it!(author)2016-02-05

You can get free power supplies from abandoned PC computers.
People are happy to give away their old CPUs, and they can be a great source of parts (Power supplies, fans, etc.)

author
Qwertypat made it!(author)2016-02-05

Hi Mark, thanks, yes me too have a pile of them. They are stable, already encased and abundant. Yet I was often in need for different voltages like 1.5, 2, 3, 7, 9, 15 volts for powering components like sensors, IR and Laser LEDs, tiny electromotors etc. ATX and BTX PSU's don't offer that, as far as I know.

cheers

author
robertuit made it!(author)2016-02-04

Without a case ground or proper ventilation, this is bad practice and could be very dangerous.

author
Qwertypat made it!(author)2016-02-04

Hi Robert, I appreciate what you say -DIY electronic often can be dangerous.

With regards to Ground - the regarding DVD player, and most players, has no earth over the 2 wire AC powercord. The Ground in the device is 'local' and called a Floating Ground. The secondary circuitry of the power PCB is low voltage and is not directly connected to the high voltage 230AV, merely through a transformer. Earthed ground is not an essential in this setup.

True ground ('earth') is rarely used in home A/V electronics.

With regards to ventilation: the DVD player it came out was a small sized case with no ventilation at all. Also consider power adaptors 230V /5v/ 9V /14, they are crammed in plastic with no earth ground, no ventilation and higher current than the power PCB I used. Of course, power adaptors use plastics that can withstand heat, yes.

Nevertheless, thanks for you reaction and consideration !

author
Yonatan24 made it!(author)2016-02-05

If you work right with electronics, It isn't SO dangerous...

There is probably a bigger chance of dying by getting hit by a car, Than getting shocked and dying while tinkering with electronics when working with appropriate safety gear (Sorry for that example, But you know what I mean, Everything in life is dangerous...)

author
Qwertypat made it!(author)2016-02-05

tx for the relativating reply Yonatan, and yes statistics indeed give a view on how life has dangers for us. And also I think we all agree that we should do our best to lower risks when we have the reason, experience or expertise to do so.

cheers

author
mjackson42 made it!(author)2016-02-05

Thanks for posting this. Motivational.

author
robertuit made it!(author)2016-02-04

Without a case ground or proper ventilation, this is bad practice and could be very dangerous.

author
kodiak0 made it!(author)2016-02-04

Why does your DVD player have a hard drive!?

author
Qwertypat made it!(author)2016-02-04

hello kodiak, because the photos in Step 1 and 2 are from a a Harddisk recorder (HD recorder) as I mentioned. This has both a DVD player as well as a harddisk. Also as mentioned, I used a regular DVD player and some time before I made this Instructable therefore I couldn't make photos from the original DVD player anymore.

regards

qp

author
BeachsideHank made it!(author)2016-02-03

I have several of these waiting for an application to come along, I can't bring myself to toss out a fully functional power supply that may have years of service life left:

https://www.instructables.com/id/Asset-Recovery-Tip...

author
Qwertypat made it!(author)2016-02-03

Hey Hank, great Instructable you have and cool to see similar minded people doing the right thing !

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