Intro: The USB Ultraviolet Light.
I was playing around with my new drill press while brainstorming types of desk top lights, this is what was born from those sessions.
Before you jump into this project make sure you have the experience needed to complete this project. This light requires little knowledge or skill, but patience and diligence are always a must. In order to complete this project a little knowledge is needed in routing, drilling, soldering and a little common sense never hurt anyone.
Always wear eye protection and rolled-up sleeves when working with high RPM tools.
--------WARNING: prolonged exposure to ultraviolet light can cause serious eye problems, never look directly into an ultraviolet LED------
For this project you will need:
- A hole saw larger than 1 1/4"
- A 1" speed bore bit
- A router and cutting bit
- A pipe cutter or hack saw
- Some scrap wood with a depth of 3/4" or greater
- A light bulb
- A hot glue gun with glue
- Some craft foam to cover the base
- An Ultraviolet LED
- One 100 OHM resistor
- A USB cord
- Something UV reactive
Step 1: In the Shop
First off you are going to need to disassemble your light bulb. I learned how to at https://www.instructables.com/id/Concrete-Lightbulb-Wall-Hook/. To start off take your pipe cutters and match up the cutting wheel in between the first and second threads at the end of the bulb. While twisting the pipe cutters slowly increase the pressure of the cutting wheel, and don't worry about any glass breaking the space between the first and second bottom thread is void of any glass. Once you have taken off and discarded the bottom cap of the bulb you may begin breaking off the inner workings of the light bulb. Do this by snapping the glass rod which sticks out from the bottom, applying leverage with a drill bit or something similar around the inside lip of the end of the bulb and folding inward the remaining lip of metal. Now you are ready for some wood-working.
Take your 3/4" or deeper piece of wood and drill out a hole with the hole saw, having a bit in the hole saw is completely fine because it gives you the center and a space for your LED. Sometimes getting the cylinder of wood out of the hole saw is difficult, especially if you do not want to damage the wood, I used a screw driver and just knocked the wood out, but if you do damage the wood like I did just make that side the bottom of your light.
Now that you have your circular piece of wood cut its time to vice it and use a speed bore bit on it. Make sure to mark the depth on your bit or drill press so you do not drill the whole way through the cylinder. Just mark how deep the metal threads on the bulb go and begin drilling out the center.Once you have drilled out a slot for your bulb check to make sure it fits properly and adjust accordingly.
Now that you have your slot drilled and matched its time to begin routing. Securely clamp your cylinder in a clamp and adjust the depth of your cutting bit to the same depth of your USB cord, at the same time making sure that the bit is not too deep as it might cut through into your bulb slot. When you begin routing start off with a straight line radiating from the center of the bottom of your cylinder to it's side. Give enough room for the width of your cord and your electrical components by making a bubble shaped route in the wood. Once you have routed out enough space its time to install the electricity.
Step 2: Wiring Your Light
This was my first time soldering electronics, I find it relatively easy and as long as you double check your work before you solder everything will turn out fine.
You can find the resistors and LED's at any radio-shack or electronics store.
One ultraviolet LED uses 3.3-3.5 volts of electricity and uses 20 Milli-amps, and if you are using a USB cord and a USB port your power source will be 5 volts. Using a LED resistance calculator http://ledz.com/?p=zz.led.resistor.calculator the resistance needed comes out to 100 Ohms.
Once you have soldered your series circuit and are sure it works you can now hot glue it into place, also make sure no exposed wires are touching each other. While you have the hot glue gun running attach a foam base for some aesthetics.
Step 3: Adding the UV Reactive Material
While most of you do not have fifty year old archery mono filament lying around, I bet you do have something UV reactive. A quick trip to a craft store or even a dollar store will land you in a world of ultraviolet reactive florescent items. Most children's plastic bracelets and those bracelet making kits with neon green, yellow or pink polyvinyl thread are perfect for UV lights. Really anything that is neon or florescent in color is usually Ultraviolet reactive.
Step 4: Final Product
Pictures can not give justice to the warm glow these lights give off at night. They are simple and cheap to make and the LED can last you well over 10 years. I find these to be a nice night light, desk lamp and a good reading lamp. The perfect gift for any computer savvy friend.