This is a hollowed out light bulb filled with fluorescent liquid and two UV leds plus one red led immersed in the liquid. When turned on the light bulb flickers for a while then starts to pulsate randomly with the UV leds giving a spooky but rather nice look.

The bulb is held to the box by two small magnets that also is used as contacts for the power to it.

I got the inspiration for the project when I stumbled upon a web site describing a similar project.

In the last step of this instructable there are two videos of it in action.

Step 1: What You Need

To make this project yourself you need the following items:

  • Two UV leds
  • One red led
  • One PIC12F675 microcontroller
  • Three 120 ohm resistors
  • One diode
  • Two light bulbs, one should have clear glass
  • Two strong small rare earth magnets
  • Two small screws
  • A small piece of flat plastic
  • A box

Then you need some tools and other equipment like:
  • Some tiny wires
  • Soldering iron and solder
  • Wirecutter
  • Hotglue or epoxy
  • A PIC programmer
  • Clean water
  • A highlighter pen

Step 2: Preparing the Lightbulbs

The glass bulbs are incredibly strong and resilient to external force but I suggest that you hold the bulb with gloves or in a thick towel. The glass might shatter and give you a nasty cut in the hand. Some protective eyewear or at least ordinary glasses might also be a good precaution...

You need to separate the actual glass part from the metallic base of the bulb keeping both of them intact. When I tried to do that I quickly realized that it's next to impossible to do that so you need two bulbs.

Step 3: Bulb 1 - Keep the Glass

From the first bulb we will keep the glass;

The blob
'Begin by taking your wirecutter and try to snip off and pry away the soft metallic blob at the absolute bottom of the bulb.

The dark glass
When you removed it there's a small hole in the dark glassy part in the bottom where you can insert a small metallic object (small screwdriver) and carefully break the dark glass into smaller pieces.

The metallic part
You can now start to cut away the metallic part and carefully "roll" the metal from the bulb much like when you open a tin can with sardines.

Hacking away at the glass
Now we need to remove some of the glass since we need a hole large enough to get rid of the innards of the bulb. We also need the hold large enough fit three leds in it. So start by breaking of the long narrow part that sticks out inside and then very carefully enlarge the hole so you can pull out the filament from the bulb.

Step 4: Bulb 2 - Keep the Threaded Metallic Part

Here we only need to keep the threaded metallic part intact, so we can hack away without any caution or finesse.

Begin by removing the soft blob and the dark glassy part as in the previous step.

Then wrap the bulb in some newspaper and hit it with a hard object so the glass breaks. Remove the shards and start hacking away at the cement that the manufacturer used to bond the glass to the threaded metallic part.

It can take quite a while to get rid of all the cement from inside the metal, but it's not too difficult to do it.

When finished with this you've got a hollow bulb (from the other bulb) that you can insert into the threaded part from this step. The bulb should have glass about 1 cm (1/3 inch) down into the metal when fully inserted.

Step 5: Preparing the Power Connector in the Bulb

Take a piece of plastic that fits nicely in the bottom of the metal part of the bulb. Screw in two screws in it and connect a piece of wire to one of the screws and the diode to the other.

I did this by just drilling a two small holes in the plastic, putting the cable and one lead of the diode into the holes and then screwed in the screws. This makes a good contact without any soldering.

It is the lead on the diode without the ring that should be put into the hole. Otherwise it will not conduct when the polarity of the power is right.

Then glue the plastic to the metallic part from the lamp having the heads of the screws facing outwards.

Step 6: Preparing the Power Connection in the Box

Drill a hole in the top of the box and make sure that the power connector of the bulb fits in there.

Take a small piece of wood and drill two holes at the same distance between them as the screws you put in the bulb power connector. The holes should be the same size as your magnets so you can squeeze the magnet together with a a poser lead into the hole.

Glue the small piece of wood inside the box and adjust it so the screws on the bulb power connector snaps in place at the magnets and the bulb is held in place.

Step 7: The Leds

The leds must fit into the hole of the glass bulb so I filed the edges of the leds down just a bit and then glued them together.

I had a a small metallic gasket/ring that I put the three leds into and glued them in place there. By chance the gasket fitted almost perfectly onto of the opening of the glass bulb.

Solder the three long leads (the anodes / positive pin) of the leds together and solder a wire to it. Then solder the 120 ohm resistors to each of the short leads (cathodes / negative pin) of the leds.

Be sure to trim everything down as short and tight as possible.

Step 8: Test the Fluorescent Liquid

Start by taking a highligher pen and put it into clean water to get some of the fluorescent dye dissolved in it. Then put some of it into the bulb and dilute it with more water.

Connect one of the UV leds to some power (don't forget the resistor if you're not using the triad you created in the previous step) and shine it into the solution to see how it looks.

Try some different mixtures to get the effect you like the best. You really don't need much of the dye to get a nice glow.

Step 9: Test the Circuit

Before assembling it all into the bulb I recommend that you first test it. It would not be a good thing to notice that you've forgot to program the chip when everything is soldered and glued together into a tight ball.

Step 10: Finalize It

Make sure the bulb if filled up to the brim so you don't get a huge air bubble trapped in the top of the bulb. Then put the led triad in place and glue it securely and totally air/water safe onto the bulb. Double check that there really are no leaks.

Bend the leads of the chip so it becomes smaller and cut down the lengths of all lead to an absolute minimum. Solder it all together.

Apply power to the screws and check that it all still works. This is the last time you'll be able to fix any problems with the connections.

Wrap a layer of sticky tape around the chip so it doesn't get shortcircuited be any metal.

Then just glue it all together so it looks like a light bulb again and you're done!

Apply power (5 volt DC) to the box and just put the bulb into the hole so it snaps down onto the magnets. Relax and admire your handiwork.... :-)

Step 11: Schematic

Since the schematic so simple I just drew it on a piece of paper and scanned it. I didn't use electronic symbols for the components so it will be easier for a beginner to actually figure out how to connect the components together.

Step 12: Software

Here are the software that needs to be downloaded onto the PIC12F675. If you want to save some money you probably can get a 12F629 instead since they are basically the same processor. The 675 has some additional features like analogue-to-digital converters, but none of the extra features are used in this project. I just used the 675 since I already got a few of them at home.

The HEX-file are ready to be flashed into a '675 or '629 directly. If you want to tweak the code a bit get the ASM-file and open it in MPLAB.

If you need a PIC programmer there are several instructables that describes how to build one. JDM2 based PIC Programmer or Business Card PIC Programmer or 5 transistor PIC programmer.

Step 13: Videos

Here are the obligatory videos of the bulb in action...

Video of bulb in a light room

Video of bulb in a dark room
<p>I'm adding this project to my collection, but I ask that you post fresh videos. The ones here no longer work.</p>
Can you help me please? i want to have LED lamps in serial<br><br>power supply 3V<br>forward voltage 3.2-3.4<br>20mA <br><br>How many leds can i light up with 3V? Do i need a resistor for that, and how many OHM? Im a really beginner and i need help.
i used a 1n4148 diode, only one led light up :( please help;. .me<br><br>thanks!<br>CYa!
Yes.it's really cool. why dont use 5800-6500K CT to make the CRI much higher?
Very Cool! Could you use this as the primary light source for a room? That would be an awesome prank. Change the light bulb in the room to one of these. Add an ultra-sound generator at just the right frequency. Finish with stacks of dry ice hidden under all the furniture. That has to freak out someone. OMG I'm going to do that and post an instructable on it. I wont forget to give you a mention Mat. Thanks
Very cool. What is the best way to remove the cement from the screw base of the bulb.
Isopropanol Alcohol / Rubbing alcohol will dissolve it.
Okay. Thanks.
is this suitable with a pic 12f629 or 16f627(may need different code) or should i just buy one?
A little tip. The 'dark glassy stuff' and the 'cement' is (AFAIK) shellack. Soaking in it IPA (isopropanol) should dissolve it. Nice instructable!
A quick and quiet suggestion: Pure antifreeze solution (automotive) is highly fluorescent, and could be useful for this project. Some may have noticed that it seems to have an eerie "glow" on it's own in plain sunlight, but is highly reactive to "blacklight". The effect might be more desireable. Some food for thought....
Ah, I didn't know that antifreeze is fluorescent. That might be a fun tip for others, but I don't think that I can lay my hands on it here since the lowest temperatures in in winter is like +10C/+50F. :-) I've also heard that tonic water (with quinine) is really fluorescent..
Fluoroscein is the dye in antifreeze which look yellow, fluoresces green. Also in spirit levels, or just buy it. One gram should last you a lifetime. It's a red powder, not expensive. I still have 100 g I bought 40 years ago. Yes tonic water glows blueish, I think. Maybe the quinine in it...
Extraordinarily so, it is.... You should be able to find it in any auto supply store, regardless of your temperate region, as it is an ideal for all conditions despite local freezing points, even in Hawaii, for more than it's temperate qualities, it is a water-pump lubricant. Green antifreeze should be available everywhere, and being a hawaii local, it is still available there, where minimum temps dip as low as 65F at the coldest (at least on Oahu, but it is a typical range throughout the islands and all other tropical regions). Antifreeze serves also as a better coolant than water alone for cars no matter what the ambient, so it should be widely available anywhere. Just ask your local auto parts supplier. Dilution will lessen the effect, so I suggest a plastic that is immune to a nearly pure ethylene glycol content, such as those labeled "HDPE", or many other poly-ethylenes for a transparent globe....
The Project that this one was based on only had 2 LEDs in it, so how would the schematic of looked with the extra UV LED taken away?<br/>Hope that makes sense =P<br/>Great Instructable by the way <sup></sup><br/>
I've cast a large 4" ball using the resin. You just go easy on the catalyst. If it gets too hot it'll crack. I used a big glass christmas ornament for a mold & it didn't crack so I think a bulb would be safe. You want to make sure you're using casting resin & not laminating resin.
Ok, the next time I pass by my local ACE store I'll see if they have any casting resin. Or maybe I can find it in a hobby/craft store. I remember that a did some resin casting of butterflies like 30-35 years ago, but the resin was so expensive that I couldn't afford in on my allowance. Maybe the price today feels more reasonable ;-)
The UV LEDS work well for it.
Yes, the UV's are just fine, but I'm a bit disappointed with the red led. If I did another incarnation of this project I'd experiment a bit with different ways of getting the liquid more "cloudy" so the red led would possibly be more visible.
Maybe a little bit of laundry detergent. That made one of my glowing bottles cloudier. The red/orange one has it in it and the green bawls bottle has the liquid from an entire highlighter in it with a bamboo plant.
You could try polyester resin instead of RTV. You just catalyze it & it gets hard in a few hours & you can mix in dye. However, you'll need a dye that isn't water based because it won't mix w/ the plastic.
Nice.. But what happens when some idiot puts it into a 240 Volt lamp? I think to be on the safe side of things, the screw should be packed out so it won't fit at all, or tape put around it.
Probably nothing at all would happen. On a normal bulb the poles are the blob on the bottom and the threaded metallic part. In this bulb the metallic part is not connected to anything so no current can flow - and without a current nothing will happen.
ROTFL the question is WHY? %-) (a new thanatologic tool)
WHY? Hmmm.... Because it's "art" and art don't need a purpose, it's enough to just be "art" ;-)
haha nice :)
totally awesome, and I love the haruhi pic Bongmaster :P
Haruhi rox :)
At first I thought it was a dumb idea because I didn't know it would light up. But wow, really awesome idea! I look forward to trying it out.
That is pretty frickin sweet, I like

About This Instructable




Bio: Swedish expat living now living in Malaysia after spending some years working in Dubai.
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