A shot into the future: a do-it-yourself Gaussian gun
Possessing a weapon that can only be found in computer games only in the laboratory of a mad scientist or near a temporary portal to the future is cool. To watch how people indifferent to technology involuntarily fix their gaze on the device, and avid gamers hastily pick up their jaw - it’s worth spending a day to assemble a Gauss gun.
As usual, we decided to start with the simplest design - a single-coil induction gun. The experiments with multi-stage acceleration of the projectile were left to experienced electronics engineers who were able to build a complex switching system using powerful thyristors and precisely configure the moments of sequential switching on of coils. Instead, we focused on the possibility of preparing dishes from universally available ingredients. So, in order to build a Gaussian cannon, you will first have to go shopping. In the radio store you need to buy several capacitors with a voltage of 350-400 V and a total capacity of 1000-2000 microfarads, an enameled copper wire with a diameter of 0.8 mm, battery compartments for the Krona and two 1.5-volt batteries of type C, a toggle switch and a button. In photo products we’ll take five Kodak disposable cameras, in auto parts - the simplest four-pin relay from the Lada, in “products” - a pack of straws for cocktails, and in “toys” - a plastic gun, an automatic machine, a shotgun, a gun or any other gun that you want to turn into a weapon of the future.
Shake on the mustache
The main power element of our gun is an inductor. With its manufacture, it is worth starting the assembly of the gun. Take a 30 mm length of straw and two large washers (plastic or cardboard), assemble the bobbin from them with the screw and nut. Start winding the enameled wire gently on it, turn to turn (with a large diameter of the wire, this is quite simple). Be careful, do not allow sharp bends of the wire, do not damage the insulation. After finishing the first layer, fill it with superglue and start winding the next one. Do this with each layer. In total, 12 layers need to be wound. Then you can disassemble the reel, remove the washers and put the reel on a long straw, which will serve as the barrel. One end of the straw should be drowned out. It is easy to check the finished coil by connecting it to a 9-volt battery: if it holds the paper clip on it, then you have succeeded. You can insert a straw into the coil and test it in the role of a solenoid: it must actively draw a piece of paper clip into itself, and when pulsed, even throw it out of the barrel by 20-30 cm.
A capacitor bank is ideally suited for the formation of a powerful electric pulse (in this opinion, we agree with the creators of the most powerful laboratory railguns). Capacitors are good not only for their high energy intensity, but also for the ability to transfer all energy in a very short time before the projectile reaches the center of the coil. However, the capacitors must somehow be charged. Fortunately, the charger we need is in any camera: a capacitor is used there to form a high-voltage pulse for the ignition electrode of the flash. Disposable cameras are best suited to us, because the capacitor and “charging” are the only electrical components that they have, which means getting a charging circuit out of them is as easy as shelling pears.
Disassembling a disposable camera is the stage at which you should begin to exercise caution. When opening the case, try not to touch the elements of the electric circuit: the capacitor can retain charge for a long time. Having gained access to the capacitor, first close its terminals with a screwdriver with a handle made of dielectric. Only then can you touch the board without fear of getting an electric shock. Remove the brackets for the battery from the charging circuit, unsolder the capacitor, solder the jumper to the contacts of the charge button - we will no longer need it. Prepare at least five charge cards this way. Pay attention to the location of the conductive tracks on the board: you can connect to the same circuit elements in different places.
The selection of capacitors is a compromise between the energy of the shot and the charging time of the gun. We settled on four capacitors of 470 microfarads (400 V) connected in parallel. Before each shot, we wait for about a minute for the LEDs on the charging circuits to report that the voltage in the capacitors has reached the position of 330 V. The charge process can be accelerated by connecting several 3-volt battery compartments to the charging circuits in parallel. However, it should be borne in mind that powerful "C" batteries have excess current for weak camera circuits. In order for the transistors on the boards to not burn out, for each 3-volt assembly, there should be 3-5 charging circuits connected in parallel. On our gun, only one battery compartment is connected to the “charges”. All others serve as reserve stores.
Defining security zones
We will not advise anyone to hold a button under the finger that discharges the battery of 400-volt capacitors. To control the descent, it is better to install a relay. Its control circuit is connected to the 9-volt battery via the shutter button, and the controlled circuit is connected to the circuit between the coil and capacitors. Correctly assemble the gun will help the circuit diagram. When assembling a high-voltage circuit, use a wire with a cross section of at least a millimeter, any thin wires are suitable for the charging and control circuits. When experimenting with a circuit, remember: capacitors can have a residual charge. Discharge them by shorting them before touching them.
The shooting process looks like this: turn on the power toggle switch; we wait for the bright glow of the LEDs; lower the projectile into the barrel so that it is slightly behind the coil; turn off the power so that when fired, the batteries do not take energy away; take aim and press the shutter button. The result largely depends on the mass of the projectile. With the help of a short nail with a bitten off hat, we managed to shoot a can of energy drink that exploded and flooded the fountain with the editorial board. Then the cannon, cleaned of sticky soda, launched a nail into the wall from a distance of fifty meters. And the hearts of fans of science fiction and computer games amaze our gun without any shells.