Introduction: Etch a Sketch Power Supply

Picture of Etch a Sketch Power Supply

As someone who likes to take apart electronic things, I frequently pull stuff like LED's, motors, knobs, and switches out of old junk with plans to reuse them later. This instructable is not only an example of that reuse, but also the creation of a tool that allows me to test these parts quickly and easily.

By using a buck converter, I have a power supply that displays the voltage and can be adjusted, instead of always having to test parts using batteries and swapping out different battery combinations to achieve different voltages. Now that I have this power supply, I just clip the leads on and turn the knob! The Etch A Sketch is just fancy packaging.

Step 1: Materials

-an old Pocket Etch a Sketch

-Buck Converter (available here)

-a wall wart. (use the highest voltage you can find, this will be the highest voltage your power supply can reach)

-hot glue gun

-soldering iron

-solder

-dremel tool

-a sacrificial dremel bit

- 2 alligator clips

- an on/off switch

-a few inches of extra wire

-a sheet of plastic or other appropriate backing material

-rubber feet (optional)

-a patient girlfriend who trusts you enough to hold stuff while you solder it (optional but recommended)

Step 2: Cutting

Picture of Cutting

The first step in the process is to separate the surprisingly fragile red plastic from the very sturdy black plastic. Use the cutting wheel on the Dremel to carefully cut into the black. Go shallow on the first pass, checking to make sure you haven't pierced the inner compartment where the powdered aluminum is. It will be insanely messy if you do, and you'll know immediately. Another reason to be careful during this part is because the red plastic is pretty fragile and you don't want to crack it. Just take it slow and easy. Do save that compartment of aluminum powder though, you can do some fun things with it! (Hint: Thermite)

Step 3: Mess Up Your Wall Wart

Picture of Mess Up Your Wall Wart

Snip the adaptor tip off your perfectly good wall wart and strip the positive and negative wires. Screw one of the wires into either the positive or negative inputs of the buck converter. Leave the other wire for now. This will connect to the power switch later on.

Here I used an adjustable wall wart, which is completely unnecessary since for this project you will want to leave it on the highest setting, as the knobs will be what allows you to adjust it. I suggest using the highest voltage you can find. This one just happened to be the only one I had that would allow higher than 9v.

Step 4: Modify the Potentiometer

Picture of Modify the Potentiometer

The way you adjust the voltage on the buck converter is by using a screwdriver to turn the tiny screw on the potentiometer. Since I planned on using the Etch A Sketch knob, I needed to reposition the pot. Desolder the 3 pins and separate it from the main board. Then use the Dremel to file an old Dremel bit into a point that resembles a screwdriver. Make sure your point is able to fit inside your tiny potentiometer screw. Then use some hot glue to fasten this piece onto your knob. Pass the knob through the hole in the plastic and fit the pointy end into the slot in the screw. Use hot glue to hold everything in place. Then solder 3 long wires connecting the potentiometer back to the board. Alternatively, if you just happened to have a potentiometer that was the same diameter as an Etch A Sketch knob, and had a long enough rod on it, you could pass it right through the hole and fit it directly to the white knob. I was not that lucky.

Step 5: The On/Off Button

Picture of The On/Off Button

I used a button from a cheap dollar store lamp as the on/off button. By hot gluing the button into place inside the enclosure, I could attach the white knob to the outside. It took a little adjustment to make it fit exactly right, but after a few minutes I was able to click the button by pressing the Etch A Sketch knob. Solder one end of the button to the free wire you left on the wall wart. Solder the other end of the button to some wire and screw the other end to the only remaining power input connection of the buck converter. Your power button should now be fully functional!

Step 6: Running the Wires

Picture of Running the Wires

Here you can see how all the wires are connected. The plastic was notched anywhere a wire needed to make its way out. The black wires coming in from the left are from the wall wart. One goes through the power switch so you can press the knob to turn the unit on and off then returns to the buck converter as a white wire. The voltage controls are the black, red, and blue wire twisted around each other. The black and red poking out to the right lead to the alligator clips, which have been stripped on one end.

Be sure to run your wires around the outside edges if you want a nice clean look. The tricky part is getting the buck converter to sit in the middle. You may need to adjust positioning of some wires or glue them in place.

Step 7: Get Feet!

Picture of Get Feet!

I used some rubber feet from an old printer to give the buck converter enough height to press against the front plastic. Then I cut a scrap sheet of cardboard to fit the back opening of the red plastic. I covered the cardboard with shiny black plastic and put everything back together.

Step 8: It Works!

Picture of It Works!

Test your completed unit and hopefully everything powers on! If not, check all your solder joints and wiring to make sure nothing's loose. Check out the video of mine working.

If you liked this, please vote for me in the Reuse and Before and After Contests! I'd also love to see your versions of this project so please share any if you have them. If you've got any suggestions for improvements I'd love to hear those too! Thanks for reading!

Comments

arnablue (author)2016-04-12

Good... I'm also trying to set the Power supply Module in a case...

Using another potentiometer with knob.

But the main problem is to create holes for, LCD & Push-Button & LED separately...

Actually, I don't want to see the whole circuit in the case...!!

nathanaloysiusbash (author)2015-07-01

Very cool. Just a basic question, when using a buck converter is the same power supply able put out more current at a lower voltage for the same equivalent total wattage or is the output current limit the same at any voltage or it depends on the specific circuit?

I'll be honest. I don't really know the answer to that question. I don't understand enough of the inner workings of the buck converter to know exactly how it limits the voltage, or if you would be able to get more amps at 3 volts than you would at 6. But obviously you will be limited by the amount of amps your wall wart can put out. Sorry that's not much help!

Thats ok, . Thanks for the response. Very classy project. I feel like I would see something like this on etsy for like a babillion dollars.I need to make this and free myself from the obligation to collect random voltage wall warts.

Hmmm... So I'm not the only one... :)

JesusG33k (author)2015-06-30

so hollow out the etch-a-sketch and put in the power supply. Fantastic!

gravityisweak (author)JesusG33k2015-08-06

Yup! That's pretty much it! The difficult part was getting the knobs on the etch a sketch to control the power supply.

JesusG33k (author)gravityisweak2015-08-07

You could of had the moving rods separated and then go across a rubber fitting on a potentiometer.

JesusG33k (author)JesusG33k2015-08-07

Just Saying :P

gravityisweak (author)JesusG33k2015-08-09

The only problem with messing around with the moving rods is that they are inside a sealed compartment with the aluminum powder. It's incredibly messy to do anything inside there. As it is right now, the knobs do control the power supply, its just that I had to add my own components instead of using etch a sketch insides.

Otaku Kani (author)2015-08-03

Cool Instructable that I'm looking forward to putting together. Have you considered using aluminum paint on the inside of the clear plastic with just a small window to view the LED's? or possibly even better, using a similar colored window tint on the whole inside of the Etch-A-Sketch screen in which the lit LED's can be read through without seeing the other electronics.
But on another matter about your Instructable, Really dude.. After referring to the "Wall Wart" after the second time, it got pretty old and lame. Do you even know what it is really called?

gravityisweak (author)Otaku Kani2015-08-06

Thanks, I think it would be cool especially using some of the reflective window tint. It might make it so that it had a mirror finish when it was turned off, but the LEDs would shine through when it was on. Don't worry too much about the wall wart thing either, I'm fully aware that it's a little step down transformer, but everyone I know calls them wall warts. (sorry, i said it 2 more times) :)

bweaver6 (author)2015-06-30

I love this, I love repurposing old toys for new electronics.

bravoechonovember1 (author)2015-06-29

awesome!

next you need to get the etch a sketch to write the voltage!

BrettHacks (author)2015-06-29

Great idea! I love nontraditional packaging. Why does everything have to be in a boring box. I am sure you get a smile every time you fire it up!

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