Introduction: Glow Globs - USB Powered Computer Ornaments
Have fun with HOT GLUE and LEDs and make a novel USB powered desk or monitor ornament.
Glow Globs (a.k.a.The Mood Lump) will sit near your computer and endlessly cycle through colour patterns. (The animations show a sudden change - In reality the change is gradual.) You could make a couple to brighten up your workspace or give them as presents. The appeal is such that they're appreciated by anyone - not just computer geeks. Glow Globs use very few parts and can be made in a couple of hours, although a lot of that time is waiting for hot glue to cool.
There are only a few solder joints to make and these have to be done carefully but the project should be fine for a soldering novice as long as sufficient care is taken.
(I.E. seems to have trouble showing all frames of the animated GIFs, but they work fine with FireFox.)
Light up your life with GLOW GLOBS
Step 1: Parts and Tools
To make a Glow Glob you will need a USB lead - A dead (computer) mouse is an ideal donor as it has a long, thin and flexible lead. Anything else with a working USB lead will do though.
You will need a 47R resistor - That's a yellow - violet - black one. Quarter watt or half watt is ideal and 1%, 2%, 5% or 10% tolerance is OK.
You need three 5mm slow colour change RGB LEDs. These look like a normal LED but will cycle slowly through a range of colours when you connect them to a voltage. These seem quite hard to find from the main suppliers, but there's many for sale via eBay. Use the search terms "rgb led slow" on your country's eBay site. Many of these suppliers are based in the far east but I've had no problems ordering items (to the UK) in the past.
You will also need a hot glue gun and normal glue sticks - the ones which are normally translucent, go clear when melted, then go translucent again when cool.
Soldering iron and solder are a must and also a 'helping hands' type tool to hold things whilst soldering. If your eyesight is anything like mine you will also need your strongest pair of reading glasses.
Finally you need a small area of smooth metal surface and just the tiniest smear of oil or grease - cooking oil is fine.
Step 2: Preparing the USB Lead and a Word on LEDs
Cut the USB lead near the mouse so you're left with the long lead and computer end connector.
Strip back 2" or so of the cable and cut off everything in there except the red and the black wire. This is the positive (+5V) supply and ground (0V) from the computer which will power the Glow Glob.
Look at the picture of the LED. On the left hand side electrode there is a small black area. This is the integrated circuit which controls the LED switching and this side must be connected to the POSITIVE supply. This side also has a longer leg. This is important - Remember it.
Each LED will run the same sequence of colours, but because of small differences from chip to chip the speed of change will be slightly different for each. This means they will get out of sync and different parts of the Glow Glob will glow different colours at different times.
Step 3: Wiring Up the LEDs
If this isn't the messiest looking bit of assembly you have ever done then you should forget electronics and find a more suitable hobby. Glow Globs use 'birds nest' construction. The components are soldered wire to wire with no circuit board. It's messy but it works (as long as you're careful).
The eventual aim is to connect the three LEDs in parallel so the longer legs (the I.C. side) are connected together and the shorter legs are connected together, but no shorter leg must touch a longer leg. To complicate matters you need to do this in 3D as you want the LEDS to be pointing in different directions.
If you want your Glow Glob to sit on a monitor you want the LEDs to be more forward facing. I wanted this one on a desk so they are angled upwards. They should be formed into a rough triangle, about 3/8" - 1/2" (9mm to 12mm) apart.
Every one will be different but for a guide, look at my sequence of pictures and make use of your 'helping hands' tool. When you join one leg to another don't have the lead under stress as you apply solder otherwise it will spring apart when you solder near it again.
Step 4: Soldering the Resistor and Power Lead
Now you have the LEDs assembled you need to add the resistor. This can connect to either the positive or negative legs and should be positioned so it is within the other legs - not sticking out the side. Connect one end to one set of leads and leave the other end free for the moment.
Now connect the USB power lead :-
If you soldered the resistor to the POSITIVE (I.C.) side, connect the free end of the resistor to the RED (+ve) lead and the other LED legs to the black lead.
If you soldered the resistor to the NEGATIVE side, connect the free end of the resistor to the BLACK (-ve) lead and the other LED legs to the red lead.
Position the lead so the connection is within the rats-nest of LED legs. This is so we can reinforce it with glue later.
Step 5: Initial Testing and Fault Finding
Plug the USB lead into your computer and you should have the satisfaction of seeing all three LEDs light and colour cycle. If it works, unplug and go to the next step. If not, read on . . .
If your computer shows a message relating to USB port overload then you have a short between positive and negative - Look for LED legs touching.
If no LEDs light then you have most likely connected the positive and negative leads reversed - Check your wiring.
If one or two LEDs don't light then you have probably wired them the wrong way around - Check that the black dotted legs are all connected to the same point. Less likely is you have a faulty LED.
If LEDs light but stay the same colour then you have used normal LEDs - Start again!
Step 6: Let the Hot Glue Fun Begin
Fire up the hot glue gun. If you're cunning you'd have done it 5 minutes ago.
Put a drop of oil or grease on a tissue and wipe the metal plate to very lightly oil it. This will stop the glue sticking. Make a puddle of hot glue so it spreads to around 1" to 1.5" (25mm - 37mm) diameter and let it harden. This is the base.
Once the base is set, hold the LED assembly and apply globs of glue to attach the LEDs to the base at the right angle. Also tack down the USB lead to the base. Do this in stages and make sure the cable is covered and firmly fixed.
Take your time over the next stage. The eventual effect of the Glow Glob depends on how you apply the glue and 'the globbier the better' is the motto here. If you apply glue too soon it will smooth out and reduce the glow effect. A small fan blowing is useful to help cool the glue and reduce the build-time.
Plug the lead back in to light the LEDs and dribble, spot, dab or string the glue around the LEDS to build up around them. The glue stays clear for some time until it is completely cooled so take frequent breaks so you can get an idea of the eventual effect. The pictures below show the stages in a 'stringy' Glow Glob. My others are more globular.
When you've achieved the desired effect, leave it to cool fully then attach to your PC or monitor, stand back and admire your Unique Glow Glob.