LightBuddy: a Superbright LED Necklace




About: Hi I'm Angelo! I am a college student taking my engineering majors in BS-EE/ BS-ECE at the DLSU. I use my course as an inspiration for making my current projects! I've been posting projects here ever since I...

LightBuddy is a handy D.I.Y. LED necklace. It's a highly functional jewelry-gizmo that serves as a bright source of light. It's completely rechargeable and can be charged through any USB port.

Intended Purpose:

The project is ideal for illuminating dark areas for short periods of time. The 3W LED inside the necklace has a tendency to heat up. The design isn't intended to run more 15 minutes, going beyond could damage the LED. A heatsink can be added but it will take too much space.

Quick Description:

- USB Rechargeable (w/ Battery Indicator)

- Glows as bright as your AC LED bulb!

- Light weight (weighs 40-60g)

- Insturctable robot FTW! :D

Here's A Video Demo:

Last Minute Jewelry Contest Entry:

Please give this inscrutable a fighting chance! If you like it, don't forget to vote for my project in the jewelry contest! :D

Step 1: Parts & Materials

These are just alternatives. Parts are available at local stores (ex. RadioShack, Ace).


Parts & Materials:

- Two Instructable Patches (or similar)

- USB Lithium Battery Charger Module

- 3.7v 1000mAh Li-ion Battery (BL-5C)

- 3W Bright-White LED

- Tact/ Toggle Switch

- Wire


Tools & Equiptment:

- X-Acto (Hobby Knife Set)

- Leatherman Multitool

- 30W Soldering Iron

- Hot Glue Gun

Step 2: Slicing Holes

Cutting the patch with a hobby knife is the cleanest way of cutting holes for the LED and tact switch.

Step 3: Melt the Thread

Use a lighter to melt the thread around the holes, this prevents the cloth from tearing-apart.

Step 4: Battery Hack! Make the LED Run 3x Brighter

If you have enough experience with lithium batteries, I say give the hack a try. If you barely use lithium batteries, it's better to leave the battery's current limiter in tact, this way it is much safer. I have a separate Instructable for the tutorial.

Read More:Make A Cheap Lithium Battery Pack

Step 5: Add Wires on Every Component

Solder the necessary wires on each component. It's make the assembly, on step #9, much easier.

Step 6: Hot Glue the LED

Mount the 3W LED by applying a thick blob of hot glue.

WARNING: Never run the LED for more than 10 minutes, the hot glue coumelt due to the heat dissipation.

Step 7: Choose a Switch

There are tons of switches out there. I recycled mine from an broken transistor radio then hot glued it on the upper left portion of my instructable patch. I prefer the tact switch since I won't be using LED for long periods.


Pressing the tact switch should close the circuit, making the LED glow.

Step 8: Hot Glue the Remaining Parts

The charging module, battery and switch barely makes heat. A drop of hot glue should keep them intact for a lifetime.

Step 9: Wire Them All Up

Heat-up your soldering iron and follow this simple diagram! :D

Step 10: The Necklace

I have no use for my dog tag necklace. It has been lying around for years, so re-purposed it by recycling the metal-bead necklace for my LightBuddy project.

Step 11: Sewing - Borrow Mom's Sewing Kit

Most tech-geeks don't have a sewing kit but I bet everyone's mom has one! :D


Luckily, my teacher taught us how to sew clothing when I was in elementary. From what I learned and experienced, back-stitch is the strongest hand-stitched pattern. If you really have no idea on sewing, ask your mom or someone you know for help.

Here's A Video From Youtube (not mine)

Step 12: Give It a Try!

The LED should light up when the button is pressed.


I hope you enjoy the project and don't forget to vote!

- Thank You! :D



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    13 Discussions


    4 years ago on Introduction

    Powering a 3W LED for 2-3mins will generate huge amount of heat. My two cents, use silicone wire and current limiting resistor. I have seen some XML LED flashlight mod drawn as high as 2.5A, hence serious safety margin has to be specified. Use the small Piranha LED 9 LEDs or 12 LEDs module instead, it came with a current limiting resistor and temperature 5800k also better for human eyes' vision.