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The 555 FireFly

DESCRIPTION
What is the 555 firefly? It is a 555 circuit that blinks an LED. But, not any LED. The LED is a UV led dipped in Glow In The Dark (GITD) paint. The end result is that the UV light excites the paint resulting in it glowing and then fading out like a real fire fly does. This project started as an offshoot of a couple of my recent experiments with UV lasers taken from an HD DVD player and general playing around with stuff that lights up or glows. There are a couple of cool projects out there that use UV LED's in a matrix to “paint” on GITD material, making Persistence of Vision more organic looking. I started researching GITD stuff and came up with the following information: Zinc Sulfide is the original GITD material and then there is Strontium Aluminate, which is brighter and has a much longer persistence. You might think that Strontium Aluminate is immediately better but that depends on what you are trying to achieve. Having the glow fade faster might actually be useful depending on what you are trying to do. I had some GITD paint based on Strontium Aluminate from a previous project (one that didn’t actually work as well as I wanted due to the long persistence.) So I had an idea... Dip a UV led into the GITD paint and see what happens... The result was pretty cool and all I needed for a stand alone cool little project was something to turn it on briefly and then off for a while. Enter the 555 timer. These guys have been around a long time, I used to build stuff with them in my teens. To make it simple I didn't even use a PC board and chose the ultimate point to point wiring method. Here is a little video of the 555 firefly in action.
I will mail a UV LED dipped into GITD paint to the first five people who correctly identify the music in the video! Send me a private message if you know.

General Info on GITD:
General Phosphorescence
Zinc Sulfide
Strontium Aluminate

Description:

Lets Build It!
Lets Build It!
Lets Build It!
3 More Images
Lets Build It!
Lets Build It!
Lets Build It!
The Parts List:

Tools:
  • Needle Nose Pliers
  • Diagonal Cutters
  • Round Nose Pliers
  • Soldering Iron
  • “Third Hand” helping holder

The first thing to do is to make the GITD LED's. I bent the (+) lead (the longer one) into a little loop so I could hang it to drip dry after dipping. Next time I think I would use masking tape and rig up something that I could stick the LED to so it can drip and dry. The way I did it, they tend to swing around and can stick to each other if they get to close. Give them about 24 hours to fully dry. While they are drying lets build the circuit. 

Description:

The Circuit
The Circuit
The Circuit
3 More Images
The Circuit
The Circuit
The Circuit

Take the 555 timer IC and bend the leads straight. We are going to mount all the components on the leads. See the schematic for a layout of how it will all look. Cut and bend the leads for the 1 Meg resistor so that you can mount it as shown between pins 7 and 8. Solder the resistor to the 555. Now take the 22K resistor and connect it to Pin 6 and 7 using the same technique. Flip the 555 over and using an extra piece of lead from the resistors, make a connection between Pin 2 to Pin 6. Coming back to the front, form the 49 ohm resistor as shown and connect to Pin 3 leaving the other lead straight up to connect to the LED. The way the 555 works, the output stays high for a time based on the 1M resistor plus the 22K resistor as the capacitor charges, then goes low for a short time based on the 22K resistor discharging the capacitor. To get the LED to be off most of the time and on for a short time, we connect the cathode to the output of the 555 and the anode to the + supply. Now connect the LED between the 49 ohm resistor and pin 8 of the 555. The Capacitor is next and goes between pin 1 (-) and Pin 2 (+). We are using an electrolytic capacitor that is polarized. There is a nice stripe on it identifying the (-) lead. OK now for the value. In the video I used a 4.7 uF one to make it flash faster. For a real firefly effect, use a between a 22uF and a 68uF for a longer time between flashes. If you make several of these, use different value capacitors to mix it up a bit. I ordered 25 555's to make a batch. Finally, solder short wires for taping to the batteries. Red for (+) to Pin 8 and Black for (-) to Pin 1. Before powering it up, double check your wiring, which should be easy to do as you can see everything.

Description:

Powering It Up and Use:
Powering It Up and Use:

Powering It Up And Use:

Take two CR2032 cells and put them on top of each other to make one 6-Volt cell. Yes, it kinda sucks to have to use two, but as I write this my prototype has been running for 48 hours straight. And form deal extreme they are pretty inexpensive. Great for throwies too! Using the electrical tape wrap the (+) and (-) leads to the appropriate terminals of the battery and tape it all together just like a throwie. In fact, you just made an LED glowie!

These are great for kids and hiding around the house in closets. They also look cool at night. I am going to build a bunch to use for outdoor decorations.

Description:

Taking It Further
Taking it Further:

As I already had the GITD paint and it is rather expensive I began to search for less expensive alternatives. And, I know there are a lot of other very cool things that I could do with these LED's. If you put a bunch in a row and scanned them you would have a very cool and organic looking Larson Scanner without having to pwm the levels. I ordered enough to build an Matrix of them that should show some interesting patterns. I will write that up when I get the parts and build it. I also ordered 4 oz of Zinc Sulfide based GITD powder from the link below. I am going to experiment with making my own GITD paint to dip the LED's in. Just coating the LED with clear nail polish and dipping it into the powder worked pretty good.

GITD Powder

have fun blinking and glowing.

Jules

If you were wondering what I had the Economy Green GITD paint from it was this: And, the price has gone up!


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