Introduction: RGB Light Bulb USB Conversion
Hello fellow makers,
Today, you will learn the process I followed to convert this E27 base RGB LED bulb from 120V AC to run off of USB power.
Inside the bulb, there is a small transformer that will take the 120V AC and convert it into 5V DC. It's also very convenient that USB power banks and chargers output 5V DC.
This is my first Instructable, so please leave a comment, and if you think it's worthy, give me a vote in the "Make It Glow 2018" contest.
Lets get started!
Step 1: Tools and Materials
You will need:
-RGB LED remote controlled bulb. These are cheaply available on eBay for about 3$-4$
-Soldering iron and solder
-Hot glue gun and glue sticks
-Wire cutters/strippers
-Small screwdriver
OPTIONAL:
-Measurement caliper
-3D printer
-Computer for 3D design and 3D printing
Step 2: Preparing the LED Bulb
Firstly, lets remove the lens and front cover of the bulb. This can be done by grabbing it with both hands, and unscrewing the front ring from the lamp shade by twisting counter-clockwise.
Then, we proceed to lifting the circuit board out of the lamp shade, using a screwdriver to gently pry it out. This should not require any kind of force.
Once the board is lifted, cut the wires underneath, and remove the 3 screws holding the base to the lamp shade.
Step 3: Optional: 3D Design and 3D Printing
This step is optional, but creates a nicer end product.
I first measured the diameter to create the base, in my case 30mm.
I also measured the diameter of the USB wire, in my case 3mm.
A few minutes were spent on Fusion360 to design the base (as seen in picture 3) and proceeded to print the base, which took about 7 minutes.
After the base is done printing, remove it from the build plate, and clean it up to your liking.
Step 4: Preparing the Wire
First, strip the end of the USB wire about 4cm to expose the 4 internal wires.
If your USB lead is using common colors, the red should be (+) and the black should be (-). The white and green wire may be cut as short as possible.
Then we strip about 5mm insulation off of the end of these black and red wires, and tin the ends using a soldering iron and solder.
Step 5: Final Assembly
The wire is first fed through the 3D printed base, and glued in place from the inside, as shown in picture 1. (Skip if you didn't make a base)
The wires are fed through the holes in the lamp shade, as shown in picture 2.
Then the base can be hot glued onto the lamp shade, as shown in picture 3. Make sure this is neat, as it will affect the overall appearance of the final product. (Skip if you didn't make a base)
Next, we will identify the solder points to which we want to connect the wires to. In my case, the circuit board had markings for VCC and GND. Refer to picture 4 to see which points this was on my particular model.
Remove the old (white) wires a using soldering iron.
We will then feed the red and black wires through their respective holes in the circuit board, and solder them onto the solder points we noted previously.
Lastly, we push the circuit board into the bottom the of lamp shade, making sure it is properly positioned, and then replace the lens and the screw the ring back onto the front of the light.
Step 6: Final Result!
We now have a fully functional, USB powered RGB LED light, that can be controlled by remote control and only costs about 3$-4$ to build. This can be used anywhere, anytime you need ambient lighting.
The beauty of this design is that my 3 year old and 5 year old sons will now be able to use this light without the dangers of mains voltage. It is also very nice that this can be used in your car/van (I don't recommend doing this while driving), while camping, or anywhere where you need ambient lighting and mains power is unavailable.
Don't forget to comment what you liked/disliked about this project, feel free to ask any questions, and if anyone needs my 3D design, I will be more than happy to send it to you (although I recommend trying to design it yourself, as it is very simple, and a good learning experience.)
ALSO: don't forget to vote in the "Make It Glow 2018" contest for all of your favorite projects (There are many beautiful projects out there!)
Thanks for reading, and I will be posting more Instructables in the near future.
Cheers from Canada!
ArduinoMaker

Participated in the
Make it Glow Contest 2018
4 Comments
4 years ago
Awesome project! I wana try it with a 5v led strip and see how to goes.
Reply 4 years ago
That's a great idea. If I had a 5V LED strip, I would definately do it, but I only have 12v models :-/
Thanks for checking out my project! :-D
4 years ago
Thanks for sharing your build on Instructables! Do you have a link to those bulbs on ebay :D
Reply 4 years ago
Hi,
Thanks for your comment!
I bought these lamps several years ago, so I don't have specific links, but if you go into eBay and write "3W RGB LED remote control" you will find several results.
Here is a link to the search: https://www.ebay.com/sch/i.html?_from=R40&_trksid=... note that there are many different models in this search :-D
Here is a link to some of the bulbs: https://www.ebay.com/itm/E27-3W-16-Color-LED-Magic...
Just a word of advice to anyone buying these: If everyone buys from the same exact link, the seller will see an artificial increase in sales, and therefore the price on a specific listing may go up. It's happened before. That being said, using the first link and looking for your prefered listing will help avoid these types of problems.