[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!
Continue reading “[Mehdi's] Shocking Stun Gun Tutorial”
[Christopher] has put together a Prank Stun Baton to annoy his friends. It delivers a slight shock to the person on the business end of the device. Oddly, it’s powered solely by static electricity, there is no battery here and the resulting injury is no worse than touching a door knob after scooting your socks around on some shag carpet.
The design is super simple and is effectively just a rudimentary capacitor. The main housing is a PVC pipe that acts as a dielectric in the ‘cap’ system. Two separate pieces of tin foil are wrapped around the inside and outside of the PVC pipe. These layers of tin foil provide a conductive path up to the a couple of screws stuck in the end of the baton. A ping-pong ball and some foam act as an insulator between the PVC and the screws.
To charge the baton it only has to be brought close to a source of static electricity, a tube TV will do the trick. Rubbing it with a piece of wool will also work. When this is done an electrostatic field is stored in the PVC between the two pieces of tin foil, one side takes on a positive charge and the other a negative charge creating an electric potential between the two screws at the end of the baton. When something (with a low-enough resistance) shorts the screws, the stored energy on the positive screw tries to go to the negative screw, shocking the unsuspecting victim.
Need something a little more powerful? You may want to check out this other stun baton.
[Bruce Wayne] [Shenzhen] wanted a garment that would protect him from a jolt, while keeping him toasty in the cold weather. Well that’s not it at all, these are merely two of his projects using the same material in different ways.
We’re going to start with the infrared image on the right. This is a vest with chest and back pieces made of carbon tape totaling two meters of the material swirled on each side. Hook it to a power source and the carbon tape warms the wearer. Portability is something of an issue as each “element” takes 36 W of power (3A at 12V). Click through for advice on how to interface the tape with the power source.
Onto the main event… avoiding electrical shock when you get all up in the grill of that mall cop you’re hated for years. [Shenzhen's] jacket is really just an ordinary long-sleeved coat. But he separated the lining at the bottom seam and used fusible material to hold the carbon tape in place. The carbon tape provides a better conductor than your skin, preventing the shock from stunning you as it was intended. This really is the thing of superheroes, or former editors who should have known better.