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.
Continue reading “Repurpose an Old CRT Computer Monitor as a High Voltage Science Project Power Supply”
The third issue of The Hacklet has been released. In this issue, we start off with a roundup on the Sci-Fi Contest which recently concluded. After seeing the many great hacks you came up with for that contest, we’re looking forward to seeing what you think of for The Hackaday Prize.
Next up, we take a look at two hacks that deal with switching mains, which is a feature that most home automation projects need. These high voltage switches can be dangerous to build, but one hack finds a safe and cheap way to do it. The next looks at building your own high voltage circuitry.
Finally, we talk about two laser hacks. The first is practical: a device for exposing resins and masks using a laser. The second is just a really big laser, built from hardware store parts. Who doesn’t like big lasers? We definitely like big lasers, and so does the FAA.
[Jean-Noel] is fixing a broken Lurem woodworking machine. This machine uses a three-phase Dahlander motor, which has three operation modes: stop, half speed, and full speed. The motor uses a special mechanical switch to select the operating mode. Unfortunately, the mechanical bits inside the switch were broken, and the motor couldn’t be turned on.
To solve the problem without sourcing a new switch, [Jean-Noel] built his own Arduino based Dahlander switch. This consists of three relays that select the wiring configuration for each speed mode. There’s also a button to toggle settings, and two lamps to show what mode the motor is currently in.
The Arduino runs a finite-state machine (FSM), ensuring that the device transitions through the modes in the correct order. This is quite important, since the motor could be damaged if certain restrictions aren’t followed. The state machine graph was generated using Fizzim, a free tool that generates not only FSM graphs, but also Verilog and VHDL code for the machines.
The final product is housed in a DIN rail case, which allows it to be securely mounted along with the rest of the wiring. The detailed write-up on this project explains all the details of the motor, and the challenges of building this replacement switch.
The theory behind building power supplies is relatively easy, but putting it into practice and building a multi-kilovolt supply is hard. A big transformer in air will simply spark to itself, turning what could be something very cool into something you just don’t want to be around. [glasslinger] over on YouTube is an expert at this sort of thing, as shown in his 50,000 Volt power supply build. That’s a 55 minute long video, and trust us: it’s worth every minute of your time.
[glasslinger] began his build by taking an old 15,000 Volt neon sign transformer and repurposing the coils and cores for his gigantic 50,000 volt transformer. There was a small problem with this little bit of recycling: the neon sign transformer was potted with tar that needed to be removed.
To de-pot the transformer, [glasslinger] made a small oven from a helium tank, melting all the goo out with an old school gasoline torch. From there, hours and hours of cleaning ensued.
The transformer cores were cleaned up and cut down, and a new primary wound. A small-scale test (shown above) using the old secondaries resulted in a proof of concept with some very large sparks. The next step was putting the entire transformer in a box and filling it with transformer oil.
The money shot for this build comes when [glasslinger] assembles his transformer, rectifier, and all the other electronics into a single, surprisingly compact unit and turns standard wall power into a 50,000 Volt spark. You can literally smell the ozone from the video.
Continue reading “Rebuilding A 50,000 Volt Power Supply”
There are some big hackerspaces out there.
And then there’s The Geek Group.
It takes a certain chutzpah to convert a 43,000 foot former YMCA into a hackerspace. And an epic hackerspace it is, complete with 5 axis CNC machines, 3d printers, and of course, giant robots romping through a forest of Tesla coils. The Geek Group has performed live demos in front of thousands of people over the years, and inspired tens of thousands more via the internet. You don’t work this big without having some big adventures, and The Geek Group is no exception. They’ve been through roof leaks, gas pipe breaks, surprise tax bills and angry neighbors. They’ve also been dealing with their current adventure, fire.
Unless you’ve been under a rock the last few weeks, you’ve probably read about the recent fire, and ensuing cleanup at The Geek Group labs. We’ve covered the fire and its cause here on Hackaday, with no small amount of drama in our comments section. There is a small but vocal minority who don’t have many good things to say. Accusations of cults, safety violations, and tax evasion often fly. While some groups would take this lying down, the geek group put on their flame proof suits and wade through the comments. None more vocally than [Chris Boden], the president, CEO and founder.
DISCLAIMER: The interview contains questionable content and some profanity (which we’ve altered as grawlix). We have posted the transcript as it was captured, which includes some spelling and grammar issues. Please consider these things before clicking through to the interview itself.
Continue reading “Adventures In Hackerspacing: An Interview with Chris Boden of The Geek Group”
Motors are fun, and high voltage even more so. We’re guessing that’s what went through [brazilero2008]’s mind when he put together an electrostatic motor using upcycled parts he found lying around.
The electrostatic rotor works by connecting a very high voltage, low current power supply – in this case an industrial air ionizer – to a set or rotors surrounding a plastic rotor. The hot electrodes spray electrons onto the rotor, which are picked up by the ground electrodes. If the system doesn’t arc too much, you have yourself a plastic rotor that spins very, very fast.
[brazilero]’s device is made out of an aluminum turkey pan, a few acrylic tubes, and a few cardboard disks; all stuff you can find in a well-stocked trash can. After completing the device, it was taken apart and finished and screwed onto a beautiful painted jewelry box. Very cool for something you can make out of trash, and dangerous enough to be very interesting.
Continue reading “Producing Ozone at 3500 RPM”
By far the coolest projects we see are those dealing with high voltages and deep vacuums. Vacuum tubes of all types fall into this category, as do the electron microscopes we see from time to time. The king of all vacuum and electron hacks is the Farnsworth Fusor, a machine that will both transmute the elements and bathe you in neutrons. Fun stuff, and [Daniel] has a great tutorial for building your own.
[Dan]’s fusor is surprisingly simple to make. Obviously, the most important part is the vacuum chamber which in this build is based around a glass oil cup cylinder. With just a few roughly machined parts – the only tool needed to make the metal plates is a drill press – it can hold a low enough vacuum to contain a star in a jar.
For reasons of safety and sanity, [Dan] isn’t running his fusor at a high enough voltage to actually fuse deuterium into helium. This is really just a beautiful, glowey demonstration of what can be done with enough knowledge, the skills, and a handful of parts.