There’s something satisfying about creating high voltages. Sure, there are practical uses like neon signs or doing certain experiments, but be honest — you really just want to see some giant arcs lighting up your dark mad scientist lair. [Mircemk] has just the prescription for what ails you. Using a two-stage approach, he shows a simple setup that generates about 110KV from a pretty tame 15V supply.
From the 15V, there is a stage that uses a flyback transformer and a switch to generate a reasonably high voltage. The final stage is a Cockroft-Walton voltage multiplier that can produce quite a bit of voltage. You can see the impressive arcs in the video below.
The multiplier circuit found fame with experiments by Cockroft and Walton, obviously, but was actually originated in the early 1900s with a physicist named Greinacher. The circuit uses diodes as switches and charges a bank of capacitors in parallel. The discharge, however, puts the capacitors in series. Neglecting losses and loads, the output voltage is equal to the peak-to-peak input voltage times the number of stages present. Real-world considerations mean you won’t quite get that voltage out of it, but it can still provide a potent punch. Click through the break for a video of the circuit in action!
Continue reading “15 Volts To 110,000 Volts”
We’re not quite sure what to say about this DIY X-ray machine. On the one hand, it’s a really impressive build, with incredible planning and a lot of attention to detail. On the other hand, it’s a device capable of emitting dangerous doses of ionizing radiation.
In the end, we’ll leave judgment on the pros and cons of [Fran Piernas]’ creation to others. But let’s just say it’s probably a good thing that a detailed build log for this project was not provided. Still, the build video below gives us the gist of what must have taken an awfully long time and a fair amount of cash to pull off. The business end is a dental X-ray tube of the fixed anode variety. We’ve covered the anatomy and physiology of these tubes previously if you need a primer, but basically, they use a high voltage to accelerate electrons into a tungsten target to produce X-rays. The driver for the high voltage supply, which is the subject of another project, is connected to a custom-wound transformer to get up to 150V, and then to a voltage multiplier for the final boost to 65 kV. The tube and the voltage multiplier are sealed in a separate, oil-filled enclosure for cooling, wisely lined with lead.
The entire machine is controlled over a USB port. An intensifying screen converts the X-rays to light, and the images of various objects are quite clear. We’re especially impressed by the fluoroscopic images of a laptop while its hard drive is seeking, but less so with the image of a hand, presumably [Fran]’s; similar images were something that [Wilhelm Röntgen] himself would come to regret.
Safety considerations aside, this is an incredibly ambitious build that nobody else should try. Not that it hasn’t been done before, but it still requires a lot of care to do this safely.
Continue reading “Ambitious Homebrew X-Ray Machine Reveals What Lies Within”
If you need a high voltage, a voltage multiplier is one of the easiest ways to obtain it. A voltage multiplier is a specialized type of rectifier circuit that converts an AC voltage to a higher DC voltage. Invented by Heinrich Greinacher in 1919, they were used in the design of a particle accelerator that performed the first artificial nuclear disintegration, so you know they mean business.
Theoretically the output of the multiplier is an integer times the AC peak input voltage, and while they can work with any input voltage, the principal use for voltage multipliers is when very high voltages, in the order of tens of thousands or even millions of volts, are needed. They have the advantage of being relatively easy to build, and are cheaper than an equivalent high voltage transformer of the same output rating. If you need sparks for your mad science, perhaps a voltage multiplier can provide them for you.
Continue reading “How Does A Voltage Multiplier Work?”