Power Supply Pencilcase/Boombox/Fan Multibox




Introduction: Power Supply Pencilcase/Boombox/Fan Multibox

So a while ago my pencilcase was stolen. At the time I was disassembling computers, and came across a Compaq Deskpro EN SFF. I extracted the power supply, and to my surprise it had a hinge-supported opening mechanism! The idea immediately came to my mind to transform this into a pencilcase! So I did! This is an easy, low cost and fun project! You can use any power supply, but you might need to saw a bit and add a few hinges to have an opening mechanism in case of other types. Let's get started to be the coolest kid on the block-with a penilcase-block!
Please vote for my design in the Trash to Treasure contest! Thanks!

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Step 1: Materials

Not many things are needed.
-Power supply: Depending on your preference. I used a Compaq Deskpro EN Series SFF one (power supply series: PS2018), which I got for free from a school. You can pick this particular one up at a garage sale, junk PC shop, etc. (it was a common model) for free or a few bucks, or Ebay for around 18$ (search for: Compaq ps2018)


Of course you can use whatever you like, power supplies come in all shapes and sizes. You might have to saw a bit and add some hinges (by glue or screws) to create a lid/opening mechanism, but it shouldn't be too difficult.

-2 switches: Radioshack, Ebay or your garage has plenty of these. I used one for the fan and one for the amplifier, and inserted them to two existing holes (of course you can drill new ones). So the dimensions of these holes are:
a) 10,5 mm diameter round hole (cable exit) 3$

b) 25 mm long, 21 mm wide rectangular hole (AC plug) 3$

-9 volt battery 2$ (4$ for rechargeable)


-9 volt battery socket 2$


-amplifier (Kemo M031N 3,5W was used), otherwise on Ebay I would recommend a TEA2025B Mono Single Power Amplifier, or something similar. Smaller ones are available at 5V, but then you need a resistor if you keep the 9V battery setup. Anyhow, cost is around 5$


- speaker: constraints: 83 mm length, 50 mm width; 5-10w; free from old TV, otherwise 5$


-audio jack, mono, 3.5 mm 1$
-paint (spraypaint for metals is perfect) 5$

-scrap plywood

So the whole project cost around 25-30$, excluding the power supply (18$)m which you might have.

Step 2: Tools

-Hot glue


-soldering iron


-wire clippers

-masking tape


Step 3: Disassembly

So you got your power supply. Time to take it apart!
Notice: Be careful! Sharp objects may cut you inside, wear gloves and googles! Do not service anything while it is plugged in!
There are standard Phillips screws everywhere, take those out.

Cut the wires coming out of the box.

Then open up the item.

Unscrew the board from the base, and remove the base after cutting wires to the fan and the AC plug and the grounding.
Remove the board.
Congratulations! Base material is ready for transformation!

Step 4: Painting

So it is time to transform!
I used a blue paintjob, one layer, but you can leave it grey and industrial or use multiple layers, etc. What I definitely recommend is using masking tape to cover all holes on the inside before painting. In addition, if you want to keep the stickers, tape those as well. It is better to paint the top and the bottom separately- you can take it apart.

Step 5: Electronics

Now that the paint dried, time to install the fan and the sound system!

First, measure cable distances where you want to place your items. I put the amp in the lid part, and the speaker naturally to the exhaust grill. Solder the wires according to the image. The audio plug should be soldered in a way that the plug's outer core/biggest leg/ground is soldered to the 'GND' sign of the board. Otherwise just watch polarity to make things work!

Once you hooked everything up, hot glue all the parts in place according to the image. I used the corners to get a good grip and to hide wires a bit. Install the speaker, mine fits snugly into its place! Put in the switches, battery holder, etc.

Step 6: Final Steps!

You are almost done!

Time to add some extra flavor. I glued a piece of scrapwood on to the open part next to the fan, since that is where you grip the lid to open it.
I also added some stickers on the bottom, and four rubber dots to keep it from heavy erosion.
You can also add a small lock, putting it through the lid's hinge and the fans' hole, for extra security!
I added a post-it notepad too, well, for notes.

Now you are a proud owner of the most unique, most secure pencilcase in the World! And also a boombox. And a notepad. And a fan for those hot summer days.

You might add a different fan with lights, an alarm, another speaker for stereo, padding, solar panels, lights or whatever you like- I would love to see other ideas!
If you grind down the PCB, you might add that as a floor for the case!
Trash to treasure!
P.S.: Please safely depose of any components you extracted, such as the PCB. Many places collect e-waste, please kludge responsibly, and recycle/upcycle!

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    2 Discussions

    DIY Hacks and How Tos

    Clever idea. You save on waste and you have some truly unique accessories.


    Reply 3 years ago

    Thank you!