LED Jewelry

Intro: LED Jewelry

Create yourself a unique necklace or earrings that will glow in the dark!

STEP 1: Gather All the Tools and Material

The key to success is proper material and tools. Here is what you gonna need.

Tools:

• Narrow pliers - 2 kinds
• Round-nose pliers
• Side cutters
• Soldering station with 900M-T-2C soldering tip
• Tweezers
• Double sided tape
• Piece of paper

Material:

• 1mm/0.8mm straight brass rod
• SMD 1206 LEDs
• coin cell battery (CR2016, CR2025, CR2032, ..)
• tin solder
• soldering paste

STEP 2: Start With Template

I always start with a paper template. It will help you to make a precise shape. You can use some of mine own template attached or you can create your own.

STEP 3: Bend Wire Into Outline

Bend the brass rod using pliers into the shape of the outline. Take your time, make it nice.

STEP 4: Solder the Outline Ends Together

Use a tiny amount of the soldering paste and tin to solder the ends of outline wire together. Soldering paste will help the tin to nicely adhere to the brass.

STEP 5: Place the LEDs

Another magic is to use a double-sided tape as a third hand to hold the shape and LEDs in place while soldering. Use double-sided tape to hold the outline in the place. Put all the LEDs into the proper positions while the outline wire is still on tape and solder them. Keep in mind that the LEDs have electrical polarity. They need to be placed in the correct position in order to lit. Take a look at my template there is a graphic explaining how you need to place them.

Tip: Do not use different colors of the LEDs on the same necklace. Different colors have different voltage properties so you would end up only with one color lit.

Tip: Double-sided tape will lose its stickiness when heated. So you most likely have only one try to solder the LED to the brass.

STEP 6: Connecting LEDs

Now you need to interconnect all the other leads of the LEDs together to create a proper electrical circuit. Again bend the wire, place it on tape and solder to the other ends of LEDs.

STEP 7: Create Battery Holder

Solder a wire on the back of the necklace to create a pocket for a battery.

STEP 8: Done

Now place a battery into the necklace and see how nicely it lit up! There are different types of coin batteries with different diameters and thickness. The only requirement is to use 3V battery. The battery depending on the size and number of LEDs used will last around 24h.

You might be wondering why there is no current limiting resistor. Won't the LED burn? My design uses an internal resistance of the battery. The battery itself won't allow such high current to burn the LEDs. Nasty trick.

STEP 9: Make More and Share!

Make whatever shape you like, the only requirement is to create a proper circuit for the battery to lit up the LEDs.

I am Jiri Praus.

www.jiripraus.cz

Comments

[SonicBoomin]

Do you have a diamond💎 shape available?

[jmpu235]

Right Here:

[SonicBoomin]

Great work, I only need this flat and in the diamond 💎shape though

[Rose Li]

Very good project, I like it very much, but may I know how to connect the lamp beads to the necklace？

[marcbdg]

How do you get the battery wire on the back to hold? Every time we try to solder that perpendicular joint it pulls apart. How do you hold it to solder it and get it to stay with such a tiny perpendicular surface area?

[Kiremitci28]

Is there any problem to use these jewelry while they are touching my body? Is the radiation or current can damage our healty? Also, i really love this idea. Well done :) and sorry for my English.

[lukewoodbury]

I managed to get some 0204 resistors into my design as I found it was so bright to look at without them. Thanks for the inspiration!

[amjfrankenstein]

what about using small supercapacitor instead of battery?

[diy_bloke]

Will be empty in no time

[fuucilla1]

Wooow I love this !!
But how could you do to put it in on and off so the pendant won’t be lighting all the time (I think battery would went off in a short time if is like that)

[greg.schmidt.9406]

I think the idea is simplicity. Before you wear the item you slip the battery in, and when you're done wearing it, you remove it. That's why there's a "pocket" for the battery. If that is not acceptable to you, I suppose you could figure out a way to make/attach a tiny switch.

[diy_bloke]

Slip a thin piece of paper or plastic in between the battery and the connecting bar

[Arx]

This is nice and simple, but some leds won't be very reliable without any current limiting. Also, paralleled LEDs without any individual current limiting tend to hog current. This is the reason why cheap led flashlights with many paralleled LEDs tend to be uneven in brightness, and burn out over time.

Unfortunately, there's probably not a really good way to properly limit the leds and keep the design as simple, so I guess you have to decide on a reduced lifespan (total life of the led, not per cell), or a slightly more complicated design.

A single resistor in series with the coin holder set to limit the current to a safe value for a single led should reduce degradation over time, though it will also be less bright.

[indirshop]

nice :)

[greg.schmidt.9406]

I measured current draw with a single LED powered with a 3v CR2032 to be less than 20ma, so no problem. Here is a good article on the topic:
https://www.evilmadscientist.com/2009/some-thoughts-on-throwies/

[zkus]

I’m late to the party here, but I think these tend to be ok because the internal resistance of those little buttoncell batteries is like 20 ohms (vs like <1 for an AA), which probablyly isn’t too far from the resistor value you’d pick

[pjharro]

I'm no expert but if I calculate the numbers right then it would need a 100ohm resister at 3v and 30mA. I wonder that the resistance of the brass wire would be? Is it true there can not be different resistance values at different points of a circuit? Or is it because they are in parallel this means it is not one circuit?

I am interested in the answer to this :)

[CarstenW7]

As it is parallel it is possible to put a suitable resitor for every LED. That would also allow for different color in on piece, like Blue and Red which will not work together other ways.

[IamTeknik]

From an electronics point of view, this is pretty poor but its an awesome art project. As you say, no current limiting and the battery will die after about 1-2 hours of use. I think the best option would be to add small SMD resistors in series with each LED. 1206 is small but 0603 would be better and you wouldnt reduce the aesthetics of the project at all. If you can also find LED's with a Vf of 3.2V, it would naturally draw the rated current (somewhat) of about 15-20mA. Ill give this a go with 0603 LED's and series resistors for each LED. You could also get decorative with where you place the resistors.

[jiripraus]

That's true, it's no electrical beauty. But try it yourself. From theoretical point of view it is nonsense, it should not work. But experiments prove the difference. CR2032 battery can power circuit with 2 LEDs for 24h without any problem. No LED has been blown up either.