I chose to make an alcohol bottle lamp. It doesn't require batteries (makes sense she's not going to go buy batteries unless you buy them for her!).
Wasn't that hard and was nearly free since i already had the stuff
Also a great time writing this !
Step 1: Supply Up
1 alcohol bottle...everyone loves alcohol parafanalia in their appartment.
1 Highlighter yellow...if you want it to glow
i used 3 led's 2 blue and 1 UV
A pushbutton switch
And the basics needed for just about every electronics multimeter solder, soldering iron flux
razor blade or somethn else sharp
Step 2: Plan It Out and Connect the Led's
Each LED will need a resistor. Calculate it based on your rated supply voltage (using V=IR), if you're using a wallwart like i am use the rated voltage on it (actual is higher because its unregulated).
2. To connect the LED's it is easiest to soder the resistor to the lead first, it doesnt matter which + or - just be consistent (makes life easier). *R=V / I* After you solder all the led's together cut the length of wire you want (probably a little shorter than your bottle.)
3. cut a little bit of coating off the wire where you want to put the LED's, they dont have to be the same point for both + and - wires. the leads on your LED may be different lengths.
Step 3: Connecting the LED's
I had it facing directly downwards it make for a cool effect.
Once it is soldered place some heatshrink tube around the wires it where L=Distance between LED's.
Repeat for each one, did it a little different each time.
After they are all connected check for shorts, and all the other precautions.
Step 4: The Transformer/wallwart and Switch
Next measure the voltage from the transformer, say it was measured at 10V but rated for 5V. It's important when it comes to life of your LED's to regulate the voltage down to the voltage used to find the resistors on LED's.......
**if i'd built this on a breadboard i would have been able to eliminate this step, but i didnt think of that until now :'(**
Calculate an extra resistor to put on the - of your light strand
do this by taking the resistance required for your LED's with the rated voltage it needs to be subtracted from the resistance calculated using the measured voltage.
2. A switch has two phases....open and closed, no positive or negative, sometimes a common ground. Mine had no common ground so i connected the - of my light strand and - of my wallwart to a lead on my switch, and secured it tightly. Soldering it together, wrapping each lead once in electrical tape, then were covered in heat shrink. tubes...then i got lazy and covered it in more electrical tape until it filled the top of my bottle.
Did a little extra work I could have made it easier here
Step 5: And Its Readyish
cut the top out of the bottle
fill it with the ink from a highlighter
and put the strand in the the bottle.
If you made it this far
Thanks for reading!
I had a lot of fun writing this
My girlfriend liked the gift
I could have made it better in a few wasy but i didnt think it needed to be to elaborate for just a random gift, her Christmas gift will be better though