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.
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 .
DIY Flexible Printed Circuits Get some thin sheets of polyimide which have copper on one or both sides. Polyimide is a yellow polymer with a high melting temperature and is sometimes called Kapton. A common type of copper-coated polyimide is DuPont "Pyralux" material. Pyralux sheets come in many different varieties of polyimide thickness, copper thickness and adhesive thickness (the "adhesive" is between the copper and polyimide holding everything together.) Copper thickness is given in oz per square foot, while adhesive and Kapton thickness is given in mil (1 mil =0.001 inch). Top 10 Android Apps That Turn Your Phone into a Hacking Device 1.SpoofApp SpoofApp is a Caller ID Spoofing, Voice Changing and Call Recording mobile app for your iPhone, BlackBerry and Android phone. It's a decent mobile app to help protect your privacy on the phone.
Pleasant Hardware The SphereBot can plot images on spherical objects like table tennis balls, golf balls, eggs etc. It is inspired by the original EggBot by EvilMadScientist, but built from 2 old stepper motors and some steel rods (all cannibalized from old flatbed scanners), some MDF and plywood and a few 3d printed parts (printed with my MakerBot Cupcake). The electronics are simply an Arduino and two Polulu A4983 stepper motor drivers (on the bread board). The custom Arduino firmware directly interprets GCode sent over the serial port. So it’s no problem to print GCode from MakerBot Unicorn designs directly on the SphereBot. Thanks to the excellent Inkscape plugin from Marty McGuire, it’s easily possible to convert all kinds of vector drawings (eps, svg, etc) to printable GCode.
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. OLED panel could switch between sunroof and light source A sample of the OLED roof panel material, that can switch between being transparent and emitting light Image Gallery (2 images) What if your car had roof panels that let you see the sky during the day, but that lit the interior of the vehicle at night?
About MAKE Whether your project travels in a suitcase or requires a tow hitch and trailer to move it around, get on the Road to Maker Faire Challenge — you could win $2,500 to bring your project to New York City this September for World Maker Faire! Grand PrizeOne Grand Prize Winner will receive $2,500 to bring their project to World Maker Faire New York 2013. 2nd PrizeTwo Runners-up Prize Winners will each receive 1 Maker’s Notebook, a 1-year subscription to Make: Magazine, and 2 Adult weekend passes to World Maker Faire New York 2013. Contest InstructionsTo enter in the Road to Maker Faire Challenge, you will need to submit an Entry Form with all of your project details. If you are selected by the panel of judges to be the winner, you will receive $2,500 to bring your project to World Maker Faire New York 2013, September 21st & 22nd. Provide photos and additional documentation (such as video, blog, schematics).
How to Anonymize Everything You Do Online One year after the first revelations of Edward Snowden, cryptography has shifted from an obscure branch of computer science to an almost mainstream notion: It’s possible, user privacy groups and a growing industry of crypto-focused companies tell us, to encrypt everything from emails to IMs to a gif of a motorcycle jumping over a plane. But it’s also possible to go a step closer toward true privacy online. Mere encryption hides the content of messages, but not who’s communicating.
Introduction to Microcontrollers - Beginnings Posted by Michael Silva on Aug 20 2013 under Tutorials | Microcontroller Welcome to this Introduction to Microcontroller Programming tutorial series. If you are looking to learn the basics of embedded programming for microcontrollers (and a bit of embedded hardware design as well), I hope these tutorials will help you along that journey.
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. Introduction of EVA FILM - XINOLOGY As architectural design becomes more and more sophisticated, glass is playing significant role in building construction and decoration. It leads to a diversified demand in laminated glass, not only in safety and security purposes, but also aesthetics, design, art and view control etc. One of the most popular bonding interlayer films, nowadays, used for glass lamination is PVB.
How to Choose the Right Platform: Raspberry Pi or BeagleBone Black This article was originally posted at Michael Leonard’s blog and has been re-posted here. There are already many articles out there comparing Arduino, Raspberry Pi, and BeagleBone Black; this is not one of those articles. I believe it is clear that Arduino is in a different league than the Raspberry Pi or BeagleBone Black, and serves an entirely different purpose.