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Distributeur officiel de Raspberry Pi et Arduino. Plus de 2000 produits dans l’e-choppe. Tous les derniers circuits imprimés et kits innovants. Produits testés. Toutes les solutions dont vous aurez besoin pour alimenter votre passion pour l’électronique.

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Micro Tesla Coil Makes A Perfect Stocking Stuffer

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Tesla coils are always a hit around here at the office. Giant ones that play music with modern-day chain mail wearing DJ’s, ones thrown together in garages by self-proclaimed mad scientists&#…

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Building Chua's Circuit

Circuit Design

There are many variations on how to build Chua's circuit, but Figure A shows the basic design.
As you can see, there is not much to it. This is the standard Chua's circuit used in research and a number of experiments, but there are many different ways to realize the full circuit.

Chua's circuit is literally the simplest chaotic circuit. However, when building this circuit at home be aware that, as a chaotic circuit, very slight variations can cause large effects or failure of the entire circuit. A loose connection or uneven voltages will dramatically affect the output.

Building Chua's circuit on a breadboard can be a frustrating endeavor if care is not taken. Even a slight bump can loosen connections enough to wildly change the output. But that can be fun too! Also, the quality of the output from a breadboard will be quite less than that of a soldered circuit board.

The Chua's diode must be constructed as no one manufactures them. There are a number of ways to create a Chua's diode, which is actually a type of nonlinear resistor. In Figure B you can see Chua's diode made from only resistors and op-amps. Figure C is a little different and employs standard diodes. Both designs equally satisfy the circuit, but Figure B is easier to make.

The inductor can also be replaced and accurately simulated with an additional circuit called a gyrator, as shown in Figure D, out of the same components. To understand how this simulation is accomplished, please read this PDF on the Antoniou Inductance-Simulation Circuit.

Thus, with this inductor simulator, a fully realized circuit can be built from only resistors, capacitors and op-amps! [Figure E] These circuit components can be found lying around in most labs and are readily available off the shelf in any RadioShack or similiar establishment.

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How to build Chua's circuit, Chua's diode and an inductor simulator from basic components.

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Chua's circuit is the simplest electronic circuit that produces chaos-the output of this circuit never repeats the same sequence, and is a truly random signal. If you need a good source of randomness, Chua's circuit is easy to make and is built around standard components that you might have lying around. [Valentine] wrote a comprehensive guide which walks you through the process of building your own source of chaos.

The chaos of Chua's circuit is derived from several elements, most importantly a nonlinear negative resistor. Unfortunately for us, this type of resistor doesn't exist in a discrete form, so we have to model it with several other components. This resistor, also known as Chua's diode, can be created with an op-amp configured as a negative impedance converter and a couple pairs of diodes and resistors. Other variations such, as the schematic above,22`01 model Chua's diode using only op-amps and resistors.

The rest of the circuit is quite simple: only two capacitors, an inductor, and a resistor are needed. [Valentine] does note that the circuit is quite sensitive, so you might encounter issues when building it on a breadboard. The circuit is very sensitive to vibration (especially on a breadboard), and good solder connections are essential to a reliable circuit. Be sure to check out the Wikipedia article on Chua's circuit for a brief overview of the circuit's functionality and a rabbit trail of information on chaos theory.

Posted in Tagged hardware breadboarding, chaos theory, chua circuit, random number generator

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Chaos Theory In Practice: Chua's Circuit

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Chua's circuit is the simplest electronic circuit that produces chaos-the output of this circuit never repeats the same sequence, and is a truly random signal. If you need a good source...

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Making an electromagnet is as simple as wrapping some wire around a nail and taping the wire to both ends of a battery. When you're done, you can pick up some paper clips - it demonstrates the concept well, but it could use some more oomph. [Amazing Science] has done just that, making an "electric train" (YouTube link). All that's needed is some coiled copper wire, a battery and magnets thin enough to fit through the coils. The magnets snap onto both ends of the battery. Put the battery inside the coil and watch the fun! The electromagnetic force generated by the current moving through the coil pushes against the magnets attached to the battery, pushing the battery along the way.

[Amazing Science] plays with the setup a bit. Connect both ends of the coil together and the battery will travel in a loop until it's drained. Add a small hill, or even another battery/magnet set to the mix, and watch them go! We may even make a version of this ourselves to take with us to family gatherings this holiday season - it's simple, fun, and can teach the young 'uns about science while we swig some egg nog.

[via Reddit]

Posted in Tagged classic hacks battery, electromagnet, magnet

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[Amazing Science's] Simple Electric Train

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Making an electromagnet is as simple as wrapping some wire around a nail and taping the wire to both ends of a battery. When you're done, you can pick up some paper clips - it demonstra...