This is how to make a simple but very good looking jar lamp that switches on when you flip it over.
I made four as gifts for my friends, as I am leaving Beijing. They are very easy to make, but the result is a beautiful gift you can touch, feel and see.
You may be able to make it without buying any extra parts if you can scavenge and build.
All you need are a strip of old battery operated fairy lights, a soldering iron, a jar or bottle, and at least a pile of electronic scrap to get the parts you need. It really can be that simple.
Step 1: (Up)Cycle!
I have a handful of old battery operated fairy lights. They cost about $1 each, so after a year of looking cool on my bed, it's time for a change.
The one trick is to find the positive from the negative, quite easy as the PCB has a + marking. If you really can't see, then switch the lights on and check with a multimeter. Once you figure out polarity, immediately mark which end is negative. I used heat shrink for this.
Step 2: And Here's One I Made Earlier!...
The second trick is to figure out how much voltage to give them. They have a small 100 ohm resistor, but the supply comes from 3x AA cells (3.6V), and we are using a 9V battery. I played around starting with something bigger (470 ohm) and going down until I got the brightness I wanted, ending up with 270 ohms.
Tilt switches....you can make these quite easily yourself . Instructables itself have several nice ideas for how to make them from stuff you no doubt have in store if you play with electronics. In my case though, I picked up 10 low current tilt sensors for about a buck. I love Shenzhen....(tear rolls down eye)
Step 3: Solder! (Or Sodder If Speak American...)
You can dead-bug solder the parts together, and then wrap them up in tape or heat-shrink for some protection.
Remember, the cap goes over the fairy lights to give a dimming effect when switched off. The scetch and the final circuit are slightly different, but the circuit works the same.
Step 4: Preserve the Fairies in a Sterilised Jar
I used double sided tape to attach the battery and switch to the lid of a jar from IKEA.
Close it. Lock the latch. Check which way the jar is orientated. Normally facing is off, upside-down is on. I have run out of obvious things to say. Do not drop the jar from higher than 50cm onto a non-yielding surface. Please do not swallow. Remember that cold glass looks the same as hot glass, which also looks the same as very hot glass, but not the same as extremely hot glass, which glows slightly. Do not stand next to refrigerators, because if they fall over, they may crush you. You probably should not drink cocktails out of the jar, but if you do, it would look pretty cool.
Hope you liked my Instructable, and hope you consider voting for me. Its nice to make another one after so long.