So I needed something to procrastinate from homework with one day, so I decided I would make this leyden jar. I had all of the materials laying around (as do most people) and about ten minutes I didn't want to spend doing homework, so this was perfect. the design is pretty straight forward, so I will not go into a whole lot of detail. Either way, this is a perfect beginning electronics project for anyone. I do not think there is really anybody who is not capable of making this.
Step 1: Construction
Leyden jars have been around since the late1700s. They are basically a primitive capacitor. it holds charge and will discharge.
In this jar there are five main parts. the inside foil, the outside foil, the inside wire, the outside wire, and the jar itself which must be an insulator. basically if you build up a positive potential in the inside foil, and keep the outside foil grounded, it will want to make the charge on the outside equal that of the inside, so a spark will jump from the grounded outside to the inside.
To make it all you need to do is glue some aluminum foil to the outside of the jar (which needs to be glass or plastic), and tape a wire to it, glue some more foil into the inside and tape some wire to that. drill a hole in the lid of the jar and put the wire connected to the inside through it. screw on the lid and you are done.
Step 2: Charging
Once you have your leyden jar made, you need some way of charging it. You could connect the wire to the inside foil to a van de graaff generator, but if you are like me, you do not have a van de graaff generator, or any other kind of electrostatic generator. One way you could charge it that works okay, is turning on a CRT TV/ CRT computer monitor, waiting for it to light up completely, and then turning it off and stroking the screen with the wire leading to the inside foil. when you touch the inside wire to the outside wire, you should see a small spark. The way I found to work the best, is to actually simply walk across carpet wearing socks, and build up static electricity that way. All you need to do is hold onto the outside foil while you do this, and keep the striped parts of the wires close to each other. Once you build up a large enough charge, your jar will discharge from one wire to the other. I have gotten sparks up to about 3 or 4 mm. long doing this. What I love about this method of charging, is that it doesn't require the buying or making of a generator. If you make this please tell me how it works, and possible improvements I could make. Have fun!