Buck-Converter Design Demystified Page of Stepdown (buck) switching converters are integral to modern electronics. They can convert a voltage source (typically 8 V to 25 V) into a lower regulated voltage (typically 0.5 V to 5 V). Stepdown converters transfer small packets of energy using a switch, a diode, an inductor and several capacitors. Though substantially larger and noisier than their linear-regulator counterparts, buck converters offer higher efficiency in most cases.
Seeeduino Google Android Open ADK Main Board (Arduino Mega 2560 + USB Host) Introducing the next big thing in tech-world: Android Arduino open accessory development kits. Do you have a great idea for an Android accessory? Then this Seeeduino Android ADK main board is the go-to choice for DIY’ers everywhere. Using the Seeeduino, you’ll be prototyping your custom designed product in mere hours. Just search online for “Arduino tutorials” and you’ll find limitless resources teaching you how to program things like robots, washing machine controllers, automated desk lamps, fish feeders and even 3D printers.
ProCooling.com Let me explain the schematic (or circuit diagram, whatever you want to call it). The ICs on the board are Analog Devices ad1193 FET drivers (U1 and U2); these connect to the gate of the N-Channel mosfet (International Rectifier IRF 1407, M1 and M2). The 15V zener diode (D1 and D2) is just protection, to make the circuit a little safer. The FET drivers take in 12v, and turn it into 18v at a very low current, saturating the mosfet gates beyond the VGS barrier (Vs + 4). This lets the mosfet act like a very low ohm resistor, and restricts the current very little. It may produce a little heat, but it is not much (your sound card will more than likely put out more heat than this will ;) ).
Baldengineer's Review of NI's VirtualBench The first time I saw the VirtualBench from NI, I was amazed by its shear size—or lack of size. At the time, the unit I had access to an uncalibrated pre-release unit at the Austin TechShop. So I didn’t think it was fair to do a full review. Fast forward to today. Now that I’ve spent a week working with the VirtualBench I have some comments and thoughts. What follows is a review of this “All-In-One Instrument” that runs $1999 USD.
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. These discs are then placed in a LightScribe drive (a consumer-oriented piece of gear that costs less than $50), where a 780nm infrared laser reduces the graphite oxide to pure graphene. The laser-scribed graphene (LSG) is peeled off and placed on a flexible substrate, and then cut into slices to become the electrodes.
Hot Swap Power Management - ORing Controller - TPS2410 The TPS2410/11 controller, in conjunction with an external N-channel MOSFET, emulates the function of a low forward-voltage diode. The TPS2410/11 can be used to combine multiple power supplies to a common bus in an N+1 configuration, or to combine redundant input power buses. The TPS2410 provides a linear turn-on control while the TPS2411 has an on/off control method. Applications for the TPS2410/11 include a wide range of systems including servers and telecom. These applications often have either N+1 redundant power supplies, redundant power buses, or both. These redundant power sources must have the equivalent of a diode OR to prevent reverse current during faults and hotplug. Thermal photography Applications Thermal imaging can be used to document heat/AC leaks from insulation gaps on a building's facade, reveal warmer ground water inflows (either fresh or chemical-laden) or "thermal pollution" from industrial processes entering ocean-temperature waterbodies, as well as identify areas on the human body experiencing infection or stress (includes epidemiological applications). Community applications so far include both a "heat-busters" program in East Harlem and a "forensic" water quality monitoring program in the Gowanus Canal.
Tech materials of the future (and how you can make them yourself) Flexible screens, wearable computers, conductive ink, wires that move like muscles: These are the materials that will make up the gadgets of the future, and they’re being dreamed up and developed in do-it-yourself hacker labs and garages all around the world. Sure, large manufacturers are working on these kinds of materials, too, but openMaterials co-founder Catarina Mota says the real innovation is coming from the bottom up as makers, hackers, and DIY enthusiasts figure out how to do “the future” for themselves in their own home labs. Smart materials have one or more properties that can be changed by external stimuli, such as temperature, moisture, a magnetic field, or an electric current. And these kinds of materials are changing how we think about hardware and what hardware is able to do. So, Mota concluded, she’d have to make the materials she wanted by herself.
ATX Computer Power Supply Pinout and Connectors Note that all voltages are referenced to the same common (if you need to measure any voltage, connect the return lead of your voltmeter to any of the COM contacts). Also note that many brands such as Apple's Power Mac, Dell (during certain years), Compaq and HP had proprietary boards with entirely different pin designations- see this for info on some brand name power supplies. The rated current of the main Molex connector is 6A per contact. This means with the old 20-pin style you can't get more than 18A from 3.3V and 24A from 5V. That's why in early 2000's, some motherboards with 3.3V >18A and 5V >24A (mainly dual CPU AMD systems) used an auxiliary 6-pin power cable. It was removed from ATX12V spec v2.0 in 2003 because extra wires were added to P1.
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. SCC3 20A 12V Solar Charge Controller Electronic Circuit - CircuitsArchive Introduction The SCC3 is a solar charge controller, it's function is to regulate the power flowing from a photovoltaic panel into a rechargeable battery. It features easy setup with one potentiometer for the float voltage adjustment, an equalize function for periodic overcharging, and automatic temperature compensation for better battery charging over a wide range of temperatures. The design goals of this circuit were efficiency, simplicity, reliability, and the use of field replaceable parts. A medium power solar system can be built with the SCC3, a 12V solar panel that is rated from 100 milliamps to 20 amps, and a lead acid or other rechargeable battery that is rated from 500 milliamp hours to 400 amp hours of capacity. It is advisable to match the solar panel's maximum current to the battery's amp-hour rating (C), a typical battery charging current is C/20, so a 100 amp hour battery should have a solar panel rating of around 5 amps.
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. Buck Mode Switching Regulator for Solar Applications (C) G. Forrest Cook June 23, 2006 Power this project from sunlight with a CirKits solar power circuit board kit. Introduction
projects 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.