City University of New York Electrostatic Generator Essay


Well here we are, trying to do a lab that I was never able to make function. What I wanted to help you build was a device that could generate charge continuously. Otto von Guericke built the first one of these in 1663. He made a sphere out of cast sulfur. (You can melt it like plastic, but it stinks.) He mounted this ball on a shaft with a crank handle, and what you did was turn the crank while keeping one hand rubbing against the sphere. On cool, dry days, this would charge you (and the sphere) with static electricity.

Newton improved on it. Winter improved on that. Pretty soon everyone and their dog was making an electrostatic generator. The most advanced is probably the Van de Graaff Generator of 1929, where a belt scuffs against rollers, carrying high charge up to a spherical ball on top. You’ve probably seen one of these at least once on TV.

There are obvious ones and there are not-so-obvious ones. Perhaps one of the most difficult to understand is the Wimshurst Machine. Two counter-rotating plates have conductive patches on them with cross-spanning wires that lure the patches into polarizing while connected, then spin them into position where like charge is pushing against itself so hard that it jumps off the patches entirely. There is a vaguely similar device called a “dirod,” too.

Or just as peculiar is the Kelvin Water Dropper, where water falling out of two holes in a bucket is polarized by the presence of two wires connected to charged metal cans beneath, but tricked into falling into the wrong bucket, adding to their charges instead of reducing them. This is not exactly how thunderclouds charge up, but we don’t know for certain exactly how they charge themselves.

Your mission is to find an ELECTROSTATIC GENERATOR described online, in a book, in a video, or wherever, tell me in Canvas which one you picked, and why you like it (or hate it, if applicable). That’s all I want. Type it in as a Text Entry.

Now even I am not so dense that if you all pick the same exact one from the same exact source, my eyebrow won’t be raised. I’m not asking you to build anything. Just read about one of these devices or watch a video on it. There are so very many, and countless variants of each one. There are people who build these as a hobby and post their work on YouTube. There are collectors and museums and on and on and on.

Have fun!