Steampunk extraordinaire [Jake von Slatt] has released his latest creation. This time he’s built a Wimshurst machine from mostly 3D printed parts. The Wimshurst machine is an electrostatic generator and was originally invented in the late 1800’s by James Wimshurst. It uses two counter-rotating disks to generate an electrostatic charge which is then stored in two Leyden jars. These jars are also connected to a spark gap. When the voltage raises high enough, the jars can discharge all at once by flashing a spark across the gap.
[Jake’s] machine has a sort of Gothic theme to it. He designed the parts using Autodesk’s 123D Design. They were initially printed in PLA. Skate bearings were used in the center of the disks to ensure a smooth rotation. The axle was made from the fiberglass shaft of a driveway reflector. The vertical supports were attached the base with machine screws.
The Leyden jars were made from sections of clear plastic tube. The caps for the jars were 3D printed and are designed to accept a short length of threaded 1/8″ pipe. Copper wire was used for the interior contacts and are held in place with electrical tape. The metal sectors on each disk were made from pieces of cut aluminum tape.
You may be wondering how this machine works if it’s almost entirely made out of plastic. [Jake] actually painted most of the parts with a carbon paint. This makes them electrically conductive and he can then use the parts to complete electrical circuits. Unfortunately he found this to be rather ineffective. The machine does work, but it only produces sparks up to 1/2″ in length. For comparison, his other machine is capable of 6″ sparks using similar sized Leyden jars.
[Jake] actually tried rebuilding this project using ABS, thinking that the PLA may have been collecting moisture from his breath, but the result is still only 1/2″ sparks. He suspects that the bumpy surface of the plastic parts may be causing the charge to slowly leak away, preventing a nice build up. He’s released all of his designs on Thingiverse in case any other hackers want to give it a whirl.
About a decade ago I started a strange little journey in my free time that cut a path across electronics manufacturing from over the last century. One morning I decided to find out how the little glowing glass bottles we sometimes call electron tubes worked. Not knowing any better I simply picked up an old copy of the Thomas Register. For those of you generally under 40 that was our version of Google, and resembled a set of 10 yellow pages.
I started calling companies listed under “Electron Tube Manufacturers” until I got a voice on the other end. Most of the numbers would ring to the familiar “this number is no longer in service” message, but in one lucky case I found I was talking to a Mrs. Roni Elsbury, nee Ulmer of M.U. Inc. Her company is one of the only remaining firms still engaged in the production of traditional style vacuum tubes in the U.S. Ever since then I have enjoyed occasional journeys down to her facility to assist her in maintenance of the equipment, work on tooling, and help to solve little engineering challenges that keep this very artisanal process alive. It did not take too many of these trips to realize that this could be distilled down to some very basic tools and processes that could be reproduced in your average garage and that positive, all be it rudimentary results could be had with information widely available on the Internet.
[Matt] works at a neon sign power supply company. When a vendor error left him with quite a few defective high voltage transformers, he couldn’t bring himself to toss them in the bin. [Matt] was able to fix the transformers well enough to work, and the idea for a high voltage keyboard began to brew. Unfortunately, the original transformers were not up to the task of creating a musical arc. At that point the project had taken on a life of its own. Matt grabbed some higher power transformers and started building.
The keyboard has 25 keys, each connected to an individual high voltage circuit with its own spark gap. The HV circuit is based upon a IR2153D self-oscillating half-bridge driver. (PDF link). The 2153D is modulated by a good old-fashioned 555 timer chip. No micros in this design, folks! The output of the IR2153D switches a pair of N-channel MOSFETS which drive the flyback transformers.
[Matt] created 25 copies of his circuit and built them up on individual PCBs. He assembled everything on a wooden board shaped roughly like a grand piano. The final project looks great – though [Matt] admittedly has no musical ability, so we can’t hear AC/DC flying out of those spark gaps just yet.
If you do want to hear sparks playing music, check out the OneTesla project we saw at MakerFaire NY 2013.
If you’ve ever wanted to build a Tesla coil but found them to be prohibitively expensive and/or complicated, look no further! [Richard] has built a solid-state Tesla coil that has a minimum of parts and is relatively easy to build as well.
This Tesla coil is built around an air-core transformer that steps a low DC voltage up to a very high AC voltage. The core can be hand-wound or purchased as a unit. The drive circuit is where this Tesla coil built is set apart from the others. A Tesla coil generally makes use of a spark gap, but [Richard] is using the Power Pulse Modulator PWM-OCXi v2 which does the switching with transistors instead. The Tesla coil will function with one drive circuit but [Richard] notes that it is more stable with two.
The build doesn’t stop with the solid-state circuitry, though. [Richard] used an Arduino with software normally used to drive a speaker to get his Tesla coil to play music. Be sure to check out the video after the break. If you’re looking for a Tesla coil that is more Halloween-appropriate, you can take a look at this Tesla coil that shocks pumpkins!
Jacob’s Ladders are a staple experiment in any self-respecting mad scientist’s lair — err, a hacker’s workshop. And why not? High voltage, arcing electricity, likely more than enough to kill you even — brilliant! But in all their awesomeness, Jacob’s ladders really aren’t that complex.
In [Kevin Darrah’s] latest tutorial he shows us how to make one out of a transformer taken from an oil furnace. Why exactly does an oil furnace even have a high voltage transformer in the first place? They’re actually used as the ignition source, like a pilot light!
The one [Kevin] has is a 110VAC to 10,000VAC transformer, which puts out about 20mA (probably enough to kill you). And to turn it into a Jacob’s Ladder, you’ll just need a two long stiff wires (copper is a good candidate). The wires are closest at the bottom where the transformer can easily arc — this arc then ionizes and heats the air causing it to rise, carrying the arc with it. As the arc continues up the ladder it gets longer and longer as the wires become farther apart, becoming more and more unstable until it breaks. When this happens the arc forms again at the lowest point of resistance — the bottom.
Got some empty plastic bottles in your recycling bin or cluttering up your desk? Then you’ve got a large portion of the material you need for building your own Wimshurst machine like [Thomas Kim] did. This demonstration and build video is one of the many treasures of his YouTube channel. He shows the machine in operation and then spends several real-time minutes showing how he made the heart of it using plastic bottles, the conductive brush from a laser printer, discarded CDs, and a bunch of copper wire. As a bonus, he removes the conductive material and paint from a CD with a homemade taser. As a super special bonus, there’s no EDM soundtrack to this video, just the sounds of productivity.
The Wimshurst machine is an electrostatic generator that slightly predates the Tesla coil. It works by passing a charge from one spinning disk to another disk spinning in the opposite direction. When the charge reaches the collecting comb, it is stored in Leyden jars. Finally, it gets discharged in a pretty spark and the cycle begins anew. Once you’re over shocking your friends, use your Wimshurst machine to make an electrostatic precipitator.
Finally somebody has found a good use for all those old CRT computer monitors finding their way to the landfills. [Steven Dufresne] from Rimstar.org steps us through a very simple conversion of a CRT computer monitor into a high-voltage power supply. Sure you can make a few small sparks but this conversion is also useful for many science projects. [Steve] uses the monitor power supply to demonstrate powering an ionocraft in his video, a classic science experiment using high voltage.
The conversion is just as simple as you would think. You need to safely discharge the TV tube, cut the cup off the high voltage anode cable and reroute it to a mounting bracket outside the monitor. The system needs to be earth grounded so [Steve] connects up a couple of ground cables. One ground cable for the project and one for a safety discharge rod. It’s really that simple and once wired up to a science project you have 25kV volts at your disposal by simply turning on the monitor. You don’t want to produce a lot of large sparks with this conversion because it will destroy the parts inside the monitor. The 240K Ohm 2 watt resistor [Steve] added will help keep those discharges to a minimum and protect the monitor from being destroyed.
Yes this is dangerous but when you’re working with high-voltage science experiments danger is something you deal with correctly. This isn’t the safest way to get high-voltage but if you have to hack something together for a project this will get you there and [Steve] is quite cautious including warning people of the dangers and how to safely discharge your experiment and the power supply after every use. This isn’t the first high-voltage power supply that [Steve] has constructed; we featured his home-built 30kV power supply in the past, which is a more conventional way to build a HV power supply using a doubler or tripler circuit. Join us after the break to watch the video.