Mini 3-wire Volt Meter (0 – 99.9VDC) – Put a voltage meter anywhere with this very handy display. These are often used by RC hobbyists for keeping track of batteries but we thought it would be great on a breadboard or enclosure. This is the 3-wire version of the volt meter, two wires are used to power it and the third wire is used for measurement. We also have a 2-wire version that measure it’s own power supply. Simply connect the red wire to a positive power supply from 4.5 to 28VDC, and brown or black to the common ground to power the display. Finally, connect the orange or white wire to whatever you want to measure the voltage of. The display has a microcontroller that will read the voltage, compare it to a stable reference and display the voltage with 0.1V precision on a 3-digit 7-segment display. it can read from 0V to 99.9VDC so it will be good for any electronic project! The meter draws 3-4mA to power the microcontroller and display. This particular LED display is a nice vivid green, which we found very readable. Mounting tabs make this module easy to attach to any box or plate.
BACK IN STOCK – Adafruit USB Power Gauge Mini-Kit – This little USB port go-between is like a speed gauge for your USB devices. Instead of hauling out a multimeter and splicing cables, plug this in between for a quick reading on how much current is being drawn from the port. Great for seeing the charge rate of your phone or tablet, checking your battery chargers, or other USB powered projects.
There are a few USB power meters out there, The Practical Meter and the USB Spypow. We wanted something that was made for makers: Reprogrammable micro-controller, analog output, TTL serial output for debugging / datalogging and of course, open source.
Data is passed through transparently from end to end, so you can use it with any USB device at any speed. The power line has a 0.1 ohm current sense resistor an an INA169 high-side current sensor that is tracked by a little ATtiny85 chip. The microcontroller is programmed to read the current draw as well as the bus voltage and light up the strip of LEDs on the side.
The blue LEDs will light up, one for each Watt of power draw (which is ~200mA at 5V nominal), with a couple levels of PWM dimming for increasing current. You can measure up to 1A of current draw – most USB ports are rated for 500mA.
The green LED is helpful to tell if you have too much droop on your power line. It stays lit as long as the voltage is higher than 4.5V, most devices won’t charge effectively once it goes below that so if the green LED goes out, you know you should check your port, shorten the USB cable, or reduce the current draw.
As an awesome extra, we also print out the voltage, current and wattage data as readable text on the TX pin at 9600 baud. Connect an FTDI friend, USB console cable, microcontroller, XBee, whatever you want that can read 9600 baud TTL serial data for datalogging, plotting or display.
Comes as a mini kit with an assembled & tested PCB plus a separate USB jack and plug as shown above. Before use, solder the jack and plug. It’ll only take you a few minutes and can be done with any soldering iron. Or, advanced users can splice it between a USB extension cable.
Please note: this is a handy gadget but it isn’t a multimeter! We do some basic calibration during test, but the serial output readings are not precise and should be used as a basic guide rather than lab-grade data plots. Assume a variance of at least 0.1V and 50mA due to noise, thermal changes, etc.
NEW PRODUCT – K-TOR Pedal Powered Generator – The Power Box – The Power Box is a pedal powered generator that generates electricity as you pedal. In addition to the two-bladed socket Americans find in their homes, The Power Box features a universal outlet that adapts to EU, UK, and other world outlet styles. Global citizens and world travelers can leave adapters and converters at home. The Power Box will work with almost any rechargeable device. Just plug your charger in the socket, pedal as if you were on a bicycle, and it will charge your device. The Power Box can power devices up to 20W.
Powerful and Versatile Twice as powerful as The Pocket Socket, The Power Box has 20 watts of generation capacity at 120 volts. This is enough to charge low power netbooks, tablets, smartphones, video devices, portable gaming devices, all sorts of stuff!
The Power Box can charge multiple devices at one time, for example four smart phones or two tablets. When used with an accessory part, the Power Box can charge a 12 volt battery. A 12 volt battery can be used to store energy and can power certain appliances that the Power Box cannot power directly.
Hands-Free Designed for continuous operation from a seated position, our pedal power generator enables you to generate electricity on a sustained basis. While this generator can be used with either hands or feet, when pedaling with your feet your hands remain free to do other things.
Light Weight and Portable The Power Box (folded) is 12 in by 5.5 in by 3.5 in. It weighs 14 lbs, 11 oz. Power output is 120 volts DC, 20 watts.
It’s convenient that the 5.5/2.1 mm center-positive DC connector is nearly ubiquitous among DIY electronics. On the other hand, the “whoops I grabbed the wrong supply and killed my LED strip” tragedy is almost a weekly occurrence in the forums. I’ve done it too. They all look the same.
You don’t need a fancy labeler for this (but they’re fun!). Tape will do. Or bread clips. Whatever, avoid the Magic Blue Smoke Monster and label all your power supplies one way or another.
When Kelenföld Power Plant [Hungary] started generating electricity in 1914, it was one of the most advanced plants of its day—though it was modernized and expanded several times since then to serve the changing energy demands of the surrounding districts.
The outdated section of the power plant, which is showcased below, isn’t completely abandoned since it’s in private ownership these days. But the two main attractions—the legendary control room and the old transformer house—are closed to the public, despite the fact that both are considered masterpieces of early 20th century industrial design. You can only visit them during one of the rare guided tours organized by enthusiastic non-governmental organizations, only a few times a year.
This model is 10 Watts and has 6 selectable outputs ranging from 3V to 12VDC and up to 1.5A output. It has a 2-prong plug, but takes 110VAC to 240VAC so you can use it anywhere with a simple plug adapter.
It comes with a range of tips, such as 2.5mm mono, 3.5mm mono, 5.5mm/2.5mm, 2.5mm/2.1mm, 4mm, etc. You could use this with just about any device or project, it’s very handy!
Multi changeable plug DC-cord.
Universal AC input 100V to 240V, 50Hz/60Hz
Universal AC input plug available (BSI, USA, Europe, Aust)
6 selectable outputs: 3V-12V MAX. 1500mA.
Over load, over current, over heat protection.
International approval CE EN60950, UL1950, CSA22.2 No.950.
EMC approval EN55022.
Extra low consumption during standby (about 8% of linear adapter).
Weight: 86g approximately.
Small size: 67x29x74mm.
Cable length: 1.54m / 60 3/4″
Below is the voltage current table and avoid higher loads!
As a result of visiting Hamfest, I ended up with a laptop to take apart – a fairly new Toshiba Satellite C675D with a broken screen. It’s not a Hamfest if you don’t bring home something to take apart of course! Today we’ll be testing the battery it came with to see if it’s salvageable.The date code says it was made in 11/2011.
Neat! Never thought of using a SMBus reader to salvage an old laptop battery. You could probably use an Arduino or Bus pirate instead of the TI eval adapter.
NEW PRODUCT – 2.1mm DC Barrel Jack to Alligator Clips – Turn a wall adapter into a mini power supply with this incredibly useful adapter. A high quality molded 2.1mm DC barrel jack is brought out to red (center positive) & black (ring negative) alligator clips. Works with just about every wall adapter, good for about 2 or 3 Amps of current and up to 24VDC.
NEW PRODUCT – 2.1mm DC Barrel Plug to Alligator Clips – Turn any battery pack into a power supply with this incredibly useful adapter. A high quality molded 2.1mm DC barrel plug is brought out to red (center positive) & black (ring negative) alligator clips. 2.1mm is a near-standard for electronics, so with this adapter you can easy clip and connect packs and wires to a power jack. Good for about 2 or 3 Amps of current and up to 24VDC.
HOUSTON – (May 7, 2013) – A group of Rice University mechanical engineering students are getting a charge out of having the coolest new shoes on campus.
As their capstone project that is required for graduation, four seniors created a way to extract and store energy with every step. Their PediPower shoes turn motion into juice for portable electronics and, perhaps someday, for life-preserving medical devices.
In celebration of New York’s Bike to Work Day, the team at Voltaic Systems mounted a 60 watt solar panel on the back of an old-school road bike and rode the streets of the city, distributing a free charge-up. It’s good for everything from phones, tablets to laptops, as pictured. Via voltaicsystems.
Here’s a recent story with updates on the s0ccket project, the collection of soccer/(foot) ball kinetic energy to be used to power lights and other devices later that night — some new developments since this innovation appeared back in 2010. Thanks to Michael Reilly for the tip.
Who ever said that play can’t change the world? The Soccket ball, developed by two Harvard alumns, is a regulation-size soccer ball containing an inductive coil mechanism that captures and stores a small electrical charge. With a tiny flip cap that reveals an 1/8″ input, after less than 30 minutes of play, the Soccket will power an LED light for 3 hours, charge a battery, or operate other small devices, including an iPhone or portable CD player.
Think powering a small LED isn’t a big deal? According to the World Bank’s 2009 report, 65% of people in Africa and 25% of Latin America still have NO access to electricity. And since soccer is one of the world’s most popular sports — particularly in African and Latin America — the Soccket ball could be a meaningful source of electricity, especially to kids who often find ways to play even in harsh environments. So far 2,500 Soccket balls have been distributed through pilot programs for kids ages 7-12 in Tlaquepaque, Mexico; and in Chicago and Newark here in the states.
The Soccket’s outer measurements are identical to a regulation ball, and, tech pack included, it weighs only two ounces more. Made with a foam core and spongy foam fabric wrapped in vinyl, it can keep rolling after a puncture, unlike conventional soccer balls. The lead engineer for the team reports that the Soccket’s bounce is a little less than standard, but they’re working to improve it to match what players are used to.
This kit uses inductive charging to transfer power “wirelessly” from one coil to the other. You put in 12v 1A on the transmitter end, and on the other end you get 5v 0.6A.
I initially had some trouble getting it setup. I was trying connectors in every different position, every combination I could think of. It took me a day to realize my power supply was set to 9v rather than 12v. Once I upped the voltage, I could hold the coils an inch away from each other and still keep a charge. I also tried putting things in between the coils to see how much interference it could take. It had no problems with a coupon book, business cards, a small plastic mint case, though it did have issues being between a remote.
Panel Current Meter – 0 to 9.99A: Put a current meter anywhere with this very handy display. This panel meter requires a DC voltage to run, and then has two thick gauge wires to measure current draw. A shunt is already on board so its very easy to hook up! (read more)
Panel Volt Meter – 4.5V to 30VDC: Put a voltage meter anywhere with this very handy display. This panel meter simply connects to whatever DC supply you are trying to track, easy to wire up! (read me)
Here’s a handy technique that I haven’t seen covered anywhere lately: DIY friction/spin welding. While welding pieces of plastic to other pieces of plastic (in this case specifically styrene, notable because of all of the hobby supplies used in model building at your local craft store) might not sound extremely exciting until you starting thinking about — 3D printing, tiny electronics enclosures, armatures and jigs. I have a feeling that Fran is definitely onto something big for your workshop, office, or hackerspace!
Citizen! New opportunities await you in the exciting field of Friction Welding….. At Home! Yes – you too can enjoy the countless wonders of permanently attaching some plastic things to other plastic things – at will. Amaze your friends! In this video you will learn how to make your own friction welder, and I demonstrate just how amazingly strong a spin-weld is. Have fun, be safe, and enjoy!
Speaking of GravityLight’s low power solution, several people have written in to request more coverage in the blog on how transformers and power supplies for DIY projects work, and how to select them. Ladyada has a tutorial up on the Adafruit Learning System that addresses quite a few of the power supply options that pertain to the types of DIY projects most frequently attempted by our community:
What is a power supply?
A power supply is a device that supplies power to another device, at a specific voltage level, voltage type and current level. For example, when we talk about a 9VDC @ 500mA power supply can provideas much as 500mA of current and the voltage will be at least 9V DC up to that maximum current level. While it sounds simple, power supplies have a lot of little hang-ups that can be very tricky for the uninitiated. For example, unregulated supplies say they can provide 9V but really may be outputting 15V! The very common 7805 regulator datasheet claims it can regulate up to 1000 mA of current, but when you put a 15V supply on one side, it overheats and shuts down! This tutorial will try to help explain all about power supplies.
Why a power supply?
When you start out with electronics, you’ll hear a lot about power supplies - they’re in every electronics project and they are the backbone of everything! A good power supply will make your project hum along nicely. A bad power supply will make life frustrating: stuff will work sometimes but not others, inconsistent results, motors not working, sensor data always off. Understanding power supplies (boring though they may be) is key to making your project work!
A lot of people don’t pay much attention to power supplies until problems show up. We think you should always think about your power supply from day one – How are you going to power it? How long will the batteries last? Will it overheat? Can it get damaged by accidentally plugging in the wrong thing?