[Mehdi’s] Shocking Stun Gun Tutorial

[Mehdi Sadaghdar] never lets little things like fire, shocks, or singed fingers get in the way of his projects.  His latest is a tutorial on making a simple electroshock device. A stun weapon creates a very high voltage, and is used in law enforcement to temporarily disable a person. [Mehdi] stresses repeatedly to not use this on anyone. If you do, he won’t like you anymore. Of course, if you’ve seen any of his previous videos, you know he’ll shock himself and set something on fire before the project is complete.

To create his stunner, [Mehdi] used a car ignition to produce a high voltage. The igniton coil, which is a specialized transformer, allowed him to generate the >10000V output needed for the stunner. The coil has a 60:1 ratio and is powered by a 12V DC supply. Since a coil is a short at DC, the system only creates a high voltage pulse when power is disconnected. However, the pulse was too short to create a satisfying arc. [Mehdi] added a capacitor, creating an LC circuit that oscillates as the charge decays, creating a nicer spark. He then used an RC circuit and a relay to create a simple oscillating switch. For the finishing touch, he created a spark gap on the secondary of the transformer with two nails. In typical [Mehdi] fashion, he nearly fried his digital caliper in the process.

The end result is a nice spark that warms the cockles of [Mehdi’s] fibrillating heart. We commend him for being such a brave masochist in the name of science.  Check out his tutorial after the break!

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Copper vapor laser is amazing

What better way to spend a few months in the workshop than by heating Copper chloride to 400° C, building rotary spark gaps and 30kV capacitors, playing with high vacuums and building a very powerful laser? It’s just a day in [Jon]’s life as he builds a DIY Copper vapor laser.

Copper vapor lasers require temperatures of about 1500° C, but this is only when using pure Copper. Compounds such as Copper chloride are able to bring the required temperatures for lasing down to about 400° C, a reasonable temperature for [Jon]’s home built laser tube furnace. The only problem with this setup is the requirement for two electrical pulses, one to disassociate the Copper and a second to make the Copper lase.

The professional way of creating these electrical pulses would be a Thyratron, but it seems [Jon] wanted something cooler. He built a rotary spark gap out of two 2 inch thick blocks of acrylic that allow him to perfectly time the frequency and separation of the electrical pulses needed for his laser.

There is no word on exactly how much power [Jon]’s Copper vapor laser will put out when it’s complete, but [Jon]’s build log is already an amazing display of awesome. You can check out a short video showing off [Jon]’s laser, spark gap, and huge home-made capacitor after the break.

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Tesla coil bullet-time photography


One thing we can all probably agree on is that Tesla coils are one part high-voltage electricity and two parts pure awesome. [Rob Flickenger] thinks so too, and he built a pretty nice one in his workshop some time ago. He took a bunch of pictures showing off the coil’s capabilities, but he thought that one photo taken from a single angle didn’t do much to relay just how fantastic it is to watch a Tesla coil in action.

Taking a cue from the Matrix movies, he bought a stack of Canon point and shoot cameras and constructed a bullet time rig in his workshop. In order to get the pictures just right, he flashed each camera with a customized version of the CHDK firmware that allowed him to trigger all ten shutters with a single button press. A few scripts help facilitate collecting all of the images for processing, after which he identifies the good shots and stitches them together. You can see the awesome results in the video below.

[via LaughingSquid]

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Jacob’s Ladder


[jandgse812] shows us how to build a Jacob’s Ladder from mostly household parts.   The bulk of the instructions for this project are included in the downloadable document, there is a downloadable video as well. Be sure to follow to the end where he shows us a much safer and possibly better looking revision. The Jacob’s Ladder has become standard fair for any mad scientists laboratory. If you plan on having a workshop suited for world domination, it absolutely must have one of these in it. Be careful though, the high voltage can be deadly.