One of the big problems in the world of printed solar cells is scale: it’s much easier to print a cell the size of a fingernail than one of useful size. Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) believes a process announced last week changes all that.
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.
NEW PRODUCTS – 2-Way and 4-Way 2.1mm DC Barrel Jack Splitters – Double up or quadruple your power adapters with these wonderfully simple 4-way and 2-way power jack splitters. All you have to do is connect a standard 5.5mm/2.1mm sized plug into one end, and behold, two or four identical plugs to use! We like the rugged molding on these adapters, and they’re really handy when you have a project with multiple pluggable devices.
NEW PRODUCT – Alkaline 9V Battery – Battery power for your portable project! These batteries are high quality at a good price, and work fantastic with any of the kits or projects in the shop that use 9V.
These batteries are Alkaline (MnO2) chemistry, with a voltage range of 9.6V (fresh) to 4.8V (dead). The mAh capacity depends on discharge usage but at 50mA rate it is about 500mAh (check the datasheet in the download tab for more details).
The batteries come pre-attached with a genuine 2-pin JST-PH connector as shown and include the necessary protection circuitry. Because they have a genuine JST connector, not a knock-off, the cable wont snag or get stuck in a matching JST jack, they click in and out smoothly.
The included protection circuitry keeps the battery voltage from going too high (over-charging) or low (over-use) which means that the battery will cut-out when completely dead at 3.0V. It will also protect against output shorts. However, even with this protection it is very important that you only usea LiIon/LiPoly constant-voltage/constant-current charger to recharge themand at a rate of 150mA or less. We suggest our Micro Lipo charger, which has a 100mA default rate. Like most lipos, the batteries we sell do not have thermistors built in. This is why we suggest charging at 1/2C or even less – 100mA is a good rate, and available from any USB port if using a USB-powered charger.
Additional safety notes: Do not use a NiMH/NiCad/lead-acid charger! Also, do not abuse these batteries, do not short, bend, crush or puncture. As with all Lithium ion polymer batteries and with any power source – they should be used by experts who are comfortable working with power supplies.
Details:
Weight: 4.65g
Size: 19.75mm x 26.02mm x 3.8mm / 0.77″ x 1.02″ x 0.14″
Check out this handy easy print project for the photographers in your life! From The Makers Workbench:
Being an avid photographer, I have always found it difficult keeping the batteries for my shoe mount flash organized. I have bought many different cases over the years that all claimed to solve the issue of keeping dead batteries separate from charged batteries. Unfortunately these cases usually broke after a few months of use, or they didn’t really do a good enough job for me. Being the resourceful maker I am, I decided to hit up Thingiverse and see if anyone had created a battery case that would hold 4 AA Rechargeable batteries. I was in luck and found this Customizable Battery Case. I modified it using the Makerbot Customizer and placed a recessed label on the top and bottom that says “Charged” and “Dead” respectively. Print time is about 120 minutes for 2 sets.
I printed several of the cases on my Lulzbot AO-100 3D printer, (reviewed here) and used the default settings of .40mm layer height with a .50mm nozzle. Plastic was Red ABS from Lulzbot, and was printed at 230c with the heated bed set to 110c. The bed is covered in boroxilicate glass that is inturn covered in PET tape with an ABS Glue layer applied with a paper towel. These holders fit the super long life, super low discharge Sanyo Enloop 2000mAh AA Batteries perfectly.
Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!
Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!
The Adafruit Learning System has dozens of great tools to get you well on your way to creating incredible works of engineering, interactive art, and design with your 3D printer! If you’ve made a cool project that combines 3D printing and electronics, be sure to let us know, and we’ll feature it here!
Adding a LIPO battery charger to your latest project? You might find AN10910 worth reading from NXP, which presents some strategies to reduce the risk of working with LIPO cells and battery charging in general.
Heres’s an enthusiastic write up by David Bark from FromTheTrails.com about the Adafruit Minty Boost kit as a tool for hikers — and he made some interesting observations:
I did some testing to see how much of a charge I could get out a set of batteries and here are my results below:
Normal Duracell Batteries (1150 mAH capacity): 20 % charge 40 min duration
They do make higher capacity AA batteries, so you could improve on the performance.
What I found is that the normal Duracell Batteries got extremely hot while they charge my phone, while the eneloop batteries got warm but were ok to touch.
With the unit 1.2 oz & (2) AA batteries 1.8 oz. the entire unit only weighs in at 3 oz.!! With an extra set of batteries still brings you in under 5 oz. So far this is the lightest weight option that I have found available. In addition, using rechargeable batteries that can be recharged up to 1500 times, saves money on batteries. You could put a charger in your bounce box if you really wanted to, but I’m thinking the rechargeables might be a better option for section hiking.
MintyBoost Kit – v3.0: Make your own iPod/iPhone/GPS/etc… battery-pack and recharger! This project includes all the electronic parts necessary to build your own MintyBoost: a small & simple (but very powerful) USB charger for your iPod (or other mp3 player), camera, cell phone, and any other gadget you can plug into a USB port to charge. If you have a Nintendo DS/GBA or a PSP you can buy charger cables from us, too. The charger circuitry and 2 AA batteries fit into an small space such as an Altoids gum or mint tin, and will run your iPod for hours, 2.5x more than you’d get from a 9V USB charger! You can use rechargeable batteries too. (read more)
Planning on powering that next über-low-power board of yours from a measly CR2032 coin cell? All the power to you (ug), but you might find this helpful app note from TI worth reading to understand exactly what the limitations of coin cells are, I.e.:
When designing a small wireless sensor node to be powered by the popular CR2032 coin cell, some sources claim there is a 15mA “limit” and that drawing more current is not possible or will “damage” the battery. This may give the impression that at 15mA everything works perfectly and battery capacity is great, while at 16mA nothing works. There is little public information available to explain why such a limit exists (if it indeed does exist), and little information explaining why 15mA would be a “magic number”.
Check out how Ryan Brown tests his power draw for his Halloween costume to make sure he has the battery life required:
As I mentioned in the LED Ring construction post, I wanted to make sure 4 AA batteries would power my 25 RGB LEDs through a good 3+ hours of trick-or-treating. The Adafruit doc provides a good battery life estimate, but I figured I might as well measure it.
Fortunately, I had a myDAQ handy, and hooked it up to measure battery current and voltage (above). (Note: the power consumed by the 1N4001 diode is not measured with this setup.)
I then wrote a quick LabVIEW VI to measure & log the battery voltage and current every second. This way I could see the voltage and current drop as the batteries discharged….
RGB Pixels are digitally-controllable lights you can set to any color, or animate. Each RGB LED and controller chip is molded into a ‘dot’ of silicone. The dots are waterproof and rugged. There are four flanges molded in so that you can ‘push’ them into a 12mm drill hole in any material up to 1.5mm/0.06″ thick. They’re typically used to make outdoor signs. We also have flat-backed pixels that are essentially the same, but are not as long and thin.
The pixels are connected by a 4-conductor cable. +5V (Red), Ground (Blue), Data (Yellow) and Clock (Green). Data is shifted down from one pixel to the next so that you can easily cut the strand or attach more onto the end.
Each dot is digitally controlled, with an internal 8-bit PWM LED driver (24-bit color for 16 million different shades). The pixels must be clocked by a microcontroller, we have an example code linked below that works on an Arduino, it should be simple to adapt it to any other microcontroller.
The pixels use 8mm diffused RGB LEDs, with a 120 degree beam width. The total max brightness of all LEDs is about 1600mcd but with the light more evenly distributed & mixed than a clear LED. (Please note: mcd ratings of LEDs are notoriously inflated by most LED sellers, so be extra-skeptical when reviewing LED ratings!)
If you want to connect to the input of a strand (to wire it to power and a microcontroller) please get a receptacle connector. If you want to connect to the output, get a plug cable.
A battery is a battery, right? Well, taking a look at this meticulous AA Battery Showdown from BitBox in the UK, it is clear that there is a tremendous variability in power and battery life depending on the quality of construction and a number of other factors, but plotting cost against performance offers unexpected results.
And also take a look at the great resources Adafruit offers to help you to learn about batteries and how they function — to help you choose the right type of battery for your projects.
We decided to test alkaline, lithium and zinc-chloride cells to find the best AA batteries you can buy for your money on the highstreet and online. As far as we are aware, this is the largest scale discharge test of consumer batteries that has been performed. The results surprised us a lot.
We are presenting a factual survey of batteries. The selection of batteries is not exhaustive and we have not deliberately included or excluded any brands or manufacturers. We are not recommending any manufacturer or brand based on these results and leave this up to the reader to decide which batteries to buy.
In sewing, strings of various thickness and stiffness are used for piping, a type of trim inserted into a seam to define the edges or style lines of a garment or bag.
A team of researcher at LG Chem seems to add another function to the piping: they developed a Li-Ion battery in string form just a few millimeter thick, is bendable and can even be knotted without compromising it’s battery function.
The energy storage technology is based on Li-Ion chemistry just like conventional Li-Po batteries only twisted into a round, fine string instead in a flat, geometrical form factor.
Thin strands of nickel and tin coated copper wires form the anode. The researcher then spin the coated copper wires into metal yarn, wrap it around a rod to form a spring shape which functions as structural element of the string battery as well as the anode.
Johanna Nelson uses powerful X-ray imaging to study lithium-sulfur batteries, a promising technology that could some day power electric vehicles. Working with scientists at SLAC and Stanford University, Nelson took microscope snapshots of individual sulfur particles — the first real-time imaging of a lithium-sulfur battery in operation. Previous studies using standard electron microscopes showed that large amounts of sulfur disappears from the cathode after cycling, causing the battery to die. But Nelson’s team showed that sulfur particles mostly remain intact. Their results could could help scientists develop commercially viable lithium-sulfur batteries for electric cars.
If you would like more information you can read the full article here.
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