# CircuitLab

“Give it a try – this is a great idea.” “Amazingly user friendly and simple for even the novice hobbyist to dive into.” “Browser-based circuit simulator boasts a mountain of features.” “Smart Wires” Technology: Build your schematic faster than ever before with our unique, intelligent Smart Wires technology for connecting terminals and rearranging components. Proprietary Simulation Engine: An extended-precision numerical solver core plus an advanced mixed-mode event-driven simulation engine makes it easy to get simulations running quickly. Presentation-Quality Schematics: Print sharp, beautiful vector PDFs of your schematics, plus export to PNG, EPS, or SVG for including schematics in design documents or deliverables.

Using a FET as a Voltage Controlled Resistor An fet can be used as a voltage controlled resistor (vcr) where the resistance between the drain and source is controlled by the gate-source voltage. The resulting resistor is unfortunately non-linear; however, a simple linearisation circuit means that the fet vcr can be used even in situations where the non-linearities would cause difficulties. I have used this technique successfully both at audio and video frequencies.

scitoys.com - Computers and Electronics Building a computer controlled radio transmitter How would you like to send text messages to your friends without wires, and without an Internet connection, and without paying monthly fees? In this project we will build a very simple radio transmitter that you attach to a serial port on your computer. The computer then runs a free program that converts words you type into radio signals that are decoded by another computer, using a cheap radio receiver, and a sound card. With a little study, you don't even need the second computer, since the radio signals are in Morse code, which anyone can learn to decode in their head with a little practice.

Hijack Introduction HiJack is a hardware/software platform for creating cubic-inch sensor peripherals for the mobile phone. HiJack devices harvest power and use bandwidth from the mobile phone's headset interface. The HiJack platform enables a new class of small and cheap phone-centric sensor peripherals that support plug-and-play operation. HiJack has been tested with the iPhone 3G/3GS/4G, iPod Touch, and iPad devices. A Hijack app LIB is also available to help you design your own particular "ixxxx" app with this kit.

555 Square Wave Generator This is a simple square waveoscillator using a 555 timer chip. A timing interval starts when the trigger input ("tr") goes lower than 1/3 Vin, or 3.33V. When this happens, the 555 output goes high, and the 555 waits for the threshold input ("th") to reach 2/3 Vin, or 6.67V. scitoys.com - Radio Building a simple crystal radio. A crystal radio is the distilled essence of a radio. It has very few parts, it needs no batteries or other power source, and it can be built in a short time out of things you can find around the house. The reason a crystal radio does not need any batteries is the amazing capabilities of the human ear.

Graphene supercapacitors are 20 times as powerful, can be made with a DVD burner A team of international researchers have created graphene supercapacitors using a LightScribe DVD burner. These capacitors are both highly flexible (pictured below) and have energy and power densities far beyond existing electrochemical capacitors, possibly within reach of conventional lithium-ion and nickel metal hydride batteries. The team, which was led by Richard Kaner of UCLA, started by smearing graphite oxide — a cheap and very easily produced material — films on blank DVDs. 200 Transistor Circuits This will clear-up a lot of mysteries of the solar panel. Many solar panels produce 16v - 18v when lightly loaded, while other 12v solar panels will not charge a 12v battery. Some panels say "nominal voltage," some do not give any value other than 6v or 12v, and some specify the wrong voltage. You can't work with vague specifications. You need to know accurate details to charge a battery from a solar panel.

Basic Electronics {*style:<b> Get a quick start by scrolling down to the introduction below this menu table. Basic Electronics - Course Table You are at the best, free online "Basic Electronics Course". Just read the brief blocks of text, view the videos, and check out some of the screened internet links. Build A TENS Machine to Remove Pain A Tens machine is used to provide a drug free way of removing pain from your body ( TENS stands for Transcutaneous Electrical Nerve Stimulation ) .Here I will show you how to build your own Tens machine and reduce the amount of pills you use to stop pain .To Build this Tens unit, you will first need to buy a 555 timer IC . The 555 timer is very small about a quarter of the size of your finger nail .You can purchase one for about 25p from Maplins or Radio Shack etc . There are 2 types of Tens machine. High Frequency Tens uses frequencies in the range of 80 to 100 Hz. This blocks the pain impulses going to the brain .

Concise electronics for geeks Copyright (C) 2010 by Michal Zalewski <lcamtuf@coredump.cx> There are quite a few primers on electronics on the Internet; sadly, almost all of the top hits resort to gross oversimplifications (e.g., hydraulic analogies), or convenient omission, when covering subtle but incredibly important topics such as the real-world behavior of semiconductors. There are some exceptions, to be sure - but they tend to suffer from another malady: regressions into mundane, academic rigor, complete with differential equations and complex number algebra in transient analysis - a trait that is highly unlikely to be accessible, or even useful, to hobbyists. Homo ludens electronicus My interest in electronics started when I was 12 years old, although I had built electric devices (lighting systems, flashlights, solenoids, even a motor) much earlier. At age 12 I started the real thing: Radios, sound effect generators, light games, etc. This obsession of building things led to a career in electronics, but also it has become my most interesting hobby. I regularly design and build things, and now I will share my better documented projects with you. Each of the following links leads to a page giving constructional information (schematics, sometimes printed circuit layouts, and text) for an electronic project.

Un défi présent dans la vie d'un enseignant des sciences au secondaire est d'être capable de faire de beaux exercices clairs et précis. Faire des circuits électriques à la main et au tableau peur s'avérer laborieux par moment. Alors, CircuitLAb est un outil indispensable pour construire ce genre d'activité. De plus, les élèves eux-mêmes peuvent être en mesure de construire leurs propres circuits. Le concept d'électricité est complexe et parfois nébuleux puisque ce n'est pas de la matière tangible. Alors, pour les raisons mentionnées plus haut, il est encore plus important d'être clair et précis. by Mar 15

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