NEW PRODUCT – 5V 1A (1000mA) USB port power supply. Need a USB jack for charging or powering a project, but don’t want to lug around a computer? This switching supply gives a clean regulated output at up to 1000mA! 110 or 240 input, so it works in any country. The plugs are “US 2-prong” style so you may need a plug adapter, but you can pick one up at any hardware store for a $1 or so.

This adapter was specifically designed to provide 5.25V not 5V, but we still call it a 5V USB adapter. We did this on purpose to solve a problem that occurs often with USB-powered gadgets: they draw so much current than the resistance of the cable causes a voltage drop, so instead of 5V, the device sees 4.75V or so. To avoid this problem, we made the adapter 5.25V. This is because the USB power specification allows up to 5.25V, and its safe for all 5V electronics, and has the benefit of making up for any loss due to thin USB cables. Basically, you can use it where ever USB 5V power is needed, with no risk of damage, and it will happily work at the full current range, no matter what cable you use!

The adapter does not have a cable, instead there is a USB ‘A’ type port on the bottom, where you can plug any USB cable in. The data lines have resistors on them, to match what is inside of an ‘Apple iPhone’ type charger, and we tested this adapter successfully with an iPhone 4 so it ought to work with anything that can charge with an iPhone adapter.

This adapter is great for use with an Arduino, teensy, NETduino, etc.! Also good with our Lithium-polymer battery chargers, so you can just carry a USB cable.

This particular adapter is very nice, with a red indicator LED to let you know its working.

In stock and shipping now!

UPDATED PRODUCT – 12V EL wire/tape inverter. This is an inverter for EL wire and tape, similar to our pocket inverter, except it is a brick that takes 12V input instead of 2 AA batteries. This means its good for ‘fixed’ installations since you can just plug it into a 12V wall adapter. It’s also good for portable projects where you want to have a big battery pack like a 8xAA holder which will last 4-5 times longer than just 2xAA’s. It is also more powerful, and can drive twice as much EL! Another nice thing about this inverter is it’s a potted brick, so its quieter than the ‘open’ inverter with a switch.

It’s got twice the power of the pocket inverter, you can drive up to 6 meters combined of our high brightness EL wire (20 feet), or 12 meters (40 feet) of plain EL, or up to 100 square centimeters combined of panel/tape – so either a 10x10cm square or 1 meter of 1 cm wide tape.

In stock and shipping now.

Mike is just controlling a CNC over the web with an iPad, no biggie

Controlling my cnc over the web with my ipad so I mocked up a powertail with an arduino to turn the spindle on/off. Took the original housing off and it fits easily into my adafruit arduino case. Matt Ratto made an on off button for me in processing that can leave on my desktop and click remotely.

Mike makes those Arduino cases for us, and the “wearables”

UPDATED PRODUCT – 9 VDC 1000mA regulated switching power adapter – UL listed. Our 9V adapter is one of our most popular accesories, and we wanted to improve it by offering a higher amperage output and also have UL certification. So now you get 50% more current (a full Amp) and a higher quality, safer, adapter with FCC, UL and CE certification. All at the same price!

The final video I captured at the Open Hardware Summit was this interesting talk by Mark Norton. Mark is heading up the steam engine project of the Global Village Construction Set. Open-sourcing purely mechanical projects like engines is something which I’ve been thinking about a lot lately, so this talk was really exciting to me.

The idea, in the context of the GVCS, is to use this steam engine as a prime mover for a number of other tools, including electrical generators and pumps. Because of it’s simplicity, and the fact that it can be powered by pretty much anything that makes enough heat to boil water, it’s a very useful and versatile source of power. It’s also designed to be scalable: multiple single-cylinder engines can be mated via a common crankshaft to increase power output, so as to adapt to varying requirements.

You can read more about the whole project at the steam engine intro and steam engine page of the OSE wiki. If you really want to go down the rabbit hole for this topic you can browse the steam engine category page at same.

File under “power supply”

NEW PRODUCT – 12V EL wire/tape inverter. This is an equivalent inverter to our 2xAA type, except it is a brick that takes 12V input instead of 2 AA batteries. This means its good for ‘fixed’ installations since you can just plug it into a 12V wall adapter. It’s also good for portable projects where you want to have a big battery pack like a 8xAA holder which will last 4-5 times longer than just 2xAA’s. This inverter can drive up to 250 cm of high-brightness EL wire or 60 cm of EL tape.

In stock and shipping now.

Brian writes -

Power’s out due to tropical storm Irene, but there’s still sunlight out. So, I’m using a solar panel, an Adafruit adjustable breadboard power supply, and a USB hub to power my Sprint Overdrive.

NEW PRODUCT – 4-pin AT/ATX/IDE power cable. For big projects, with big power needs, an AT or ATX power supply is a handy place to grab 5V or 12VDC. Only problem is that these supplies have connectors that only plug into motherboards or hard drives. That’s where this cable comes in. It has a matching 4-pin molex connector to the hard drive/CD-ROM power cables that come out of a power supply so you can use this to grab 5V or 12V. Heck, you can even use this cable while your computer is powered, say to decorate your hard drive with LEDs or VFD/LCD displays, etc.

Note that in some older computer power supplies, the 12V supply is ‘unstable’ unless there’s a lot of current draw on the 5V line. In these cases, if you need to use the 12V line without also loading the 5V line, you can solder a 10 ohm 10 Watt power resistor between ground and 5V to load it enough to stabilize the 12V line.

In stock and shipping now.

NEW PRODUCT – Large 6V 3.7W Solar Panel. Harness even more power from the sun with this nice big solar panel. We had these custom made for us when customers let us know they needed more than what our 2W panel could provide. This panel is a 12-cell (6V) assembly mounted onto a fiberglass PCB and covered with PET plastic which protects the cells without reducing efficiency. The back has two soldering spots to easily connect and is conformal coated. The panel is thus fairly strong and lightweight but isn’t completely waterproof (since you’ll have the exposed soldering on the back. However if you place this in a box or mount it so the back is encased, it’ll be just fine.

We connected this up to our solar lipo charger and got over 550 mA to charge the battery with on a fairly sunny NYC day.

In stock and shipping now.

Ransomhall writes -

Thanks to this nice tutorial http://ladyada.net/make/solarlogger/ I’ve done a substantial upgrade! Now I can monitor and save the following data:
Voltage: Panel, Battery, Load
Current: Panel and soon battery (waiting on parts)
Temperature: battery, in case it gets too hot.

Simple Linear Adjustable Power Supply Tutorial (Based Around LM317) by JumperOneTV…

Adjustable LM317-based power supplies are an easy way to get custom voltages for your benchtop. Also check out the MIC2941 (used in our breadboard power supply http://www.adafruit.com/products/184) which has some nice benefits such as ultra-low dropout, 1.25A current output and a separate biasing pin. Its nearly a drop in replacement for the LM317 – albeit a little more expensive.

UPDATED PRODUCT – 5V 2A (2000mA) switching power supply – UL Listed. We’ve updated this adapter to be higher quality – its now UL listed! It now comes with the more common 2.1mm DC jack. Perfect for use with our LED strips, pixels, chumby hacker boards, or any other project that requires 5V DC and a bunch of current. All at the same price as before.

Andyx writes -

This is a work in progress project which uses a Solar charging MintyBoost to power an Arduino with a Proto Screw Shield on it. Attached is a 2X16 LCD using the I2C Backpack, a DHT22 Temperature and Humidity Sensor, a Waterproof DS18B20 Sensor and a 5V analog PH Probe/Adapter.

2 Watt Solar Panel Powers Bike Sharing @ Voltaic Systems

Social Bicycles released their revamped design for their bike sharing platform. It is a “GPS-enabled bike that you can find and unlock using your mobile phone.” What we like about it is that it enables companies, organizations and institutions of any size to easily create and manage their own bike share program. We think it also provides a great user experience.

The GPS locator and lock are powered by a battery system which is in turn powered by a dynamo and our 2 Watt solar panel. i.e. if the bike isn’t in motion for several days, the battery is going to stay powered up and transmitting its location.

Medium 6V 2W Solar panel 2.0 Watt. These panels come to us from Voltaic Systems, makers of fine solar-powered bags and packs. These are waterproof, scratch resistant, and UV resistant. They use a high efficiency monocrystalline cell. They output 6V at 330 mA via 3.5mm x 1.3mm DC jack connector. The substrate is an aluminum / plastic composite, specifically designed to be strong and lightweight. They can easily stand up to typical outdoor use including being dropped and leaned on. They’re very high quality and suggested for projects that will be exposed to the outdoors.

New! These now comes with 4 plastic mounting screws which makes it easy to attach the panel, even to fabric!

• Size: 4.4″ x 5.4″ / 110mm x 140mm
• Weight: 4 ounces / 120 grams
• Cell type: Monocrystaline
• Cell efficiency: 17%+

To connect, we suggest a 3.8mm OD/1.3mm ID DC jack

For some nifty ideas on what to do with your solar panels, check out Voltaic’s DIY page

In stock and shipping immediately.

Very cool project, Jeff writes -

We met Chris Jefferies a few weeks back at Maker Faire. Turns out he is using our small solar panels to do something we’ve been interested in for a while. Chris is building wireless sensor networks using open source software and hardware that could be used in a variety of applications like air quality or home energy monitoring. It looks like he was inspired by Tweetawatt and is using xBee and ASUS wifi for communication in conjunction with Pachube for data display.

Lots of Adafruit gear used!

Ever wondered about how a Voltaic solar panel is constructed? Here’s a short video showing the the composition of the panel and why its so strong.

Medium 6V 2W Solar panel 2.0 Watt. These panels come to us from Voltaic Systems, makers of fine solar-powered bags and packs. These are waterproof, scratch resistant, and UV resistant. They use a high efficiency monocrystalline cell. They output 6V at 330 mA via 3.5mm x 1.3mm DC jack connector. The substrate is an aluminum / plastic composite, specifically designed to be strong and lightweight. They can easily stand up to typical outdoor use including being dropped and leaned on. They’re very high quality and suggested for projects that will be exposed to the outdoors.

New! These now comes with 4 plastic mounting screws which makes it easy to attach the panel, even to fabric!

• Size: 4.4″ x 5.4″ / 110mm x 140mm
• Weight: 4 ounces / 120 grams
• Cell type: Monocrystaline
• Cell efficiency: 17%+

To connect, we suggest a 3.8mm OD/1.3mm ID DC jack

For some nifty ideas on what to do with your solar panels, check out Voltaic’s DIY page

In stock and shipping immediately.

Eric Walstad built this awesome off-grid weather station, using a netbook, a 135W solar cell, a desktop weather station, custom hardware, and an Adafruit adjustable breadboard power supply. He also incorporated a webcam for good measure. Here’s a timelapse movie of his cabin being built, created using custom software to combine stills from the webcam and data from the weather station. Check it out:

Very cool!

UPDATED PRODUCT! Medium 6V 2W Solar panel 2.0 Watt. These panels come to us from Voltaic Systems, makers of fine solar-powered bags and packs. These are waterproof, scratch resistant, and UV resistant. They use a high efficiency monocrystalline cell. They output 6V at 330 mA via 3.5mm x 1.3mm DC jack connector. The substrate is an aluminum / plastic composite, specifically designed to be strong and lightweight. They can easily stand up to typical outdoor use including being dropped and leaned on. They’re very high quality and suggested for projects that will be exposed to the outdoors.

New! These now comes with 4 plastic mounting screws which makes it easy to attach the panel, even to fabric!

• Size: 4.4″ x 5.4″ / 110mm x 140mm
• Weight: 4 ounces / 120 grams
• Cell type: Monocrystaline
• Cell efficiency: 17%+

To connect, we suggest a 3.8mm OD/1.3mm ID DC jack

For some nifty ideas on what to do with your solar panels, check out Voltaic’s DIY page

In stock and shipping immediately.

Enclosure for Adafruit Power Supply by renejsanchez @ Thingiverse…

This enclosure is designed to bolt to a heat sink, not pictured here. The square opening is for access to the heat sink so that the voltage regulator can be bolted directly to the heat sink. You may want to drill out/tap some of these holes [Adafruit power supply]

Hans writes -

I posted a quick How-To for the PowerSwitchTail. Thanks for including the extra components, they worked like a charm with a low-current digital output pin. Adapter Circuit – The PowerSwitchTail requires 40ma to control the internal relay. The IO-204 supplies 20ma on each of its 4 I/O channels. In order for the IO-204 to trigger the internal relay of the PowerSwitchTail, you need to connect a simple current adapter circuit. If you buy the PowerSwitchTail from Adafruit, you will recieve the necessary parts to build the adapter circuit.

NEW PRODUCT – USB/DC Lithium Polymer battery charger 5-12V – 4.2v. Charge your single-cell lithium ion/polymer battery any which way you like with this board. Have a USB connection? No problem, just plug into the miniUSB connector. Only have a wall adapter? Any standard 2.1mm DC adapter which puts out 5 to 12VDC will work fine. If both are plugged in, the charger will automatically choose whichever has the highest voltage.

Other nice things about this charger include multiple LEDs for power & charging status, including a charging LED which will blink when the battery is full. If the charger gets too hot from high-speed charging, it will slow down the charge rate automatically. You can easily adjust the charge rate up to 1.2A or down to 100mA.

We also toss in an free JST cable!

• Use USB or DC power – 5 to 12V input
• Charges one single-cell Lithium ion/polymer battery at 4.2V with constant current/constant voltage
• Three indicator LEDs – green for Power, orange for charging and red for error
• Charging LED will blink when the battery is full
• You don’t have to worry about heat dissipation in the charger, even when plugging in a 12V DC power jack – thermal protection inside will slow down the charge rate to prevent damage
• 2 JST connections so you can keep the battery plugged in and powering your project
• Terminal block connections galore (if you don’t like JST connectors) just solder in 3.5mm terminal blocks
• Default charge rate is about 280mA, but you can easily change this by soldering in a through-hole resistor on. The chip can do 100-1200 mA charging
• Safety timer will stop charging after about 14 hours
• The chip supports a standard 10K thermistor, which we have stuffed as a standard resistor. You can solder in a thermistor easily
• Lots of information in the datasheet for the MCP73861
• Fully assembled, tested and comes with a free JST cable

Battery, USB cable and DC power plug not included. But we do stock them in the store!

The USB/DC Lithium Polymer battery charger 5-12V – 4.2v is in stock and shipping now!

Slides from the NYC Resistor Battery class (PDF) by Dan Steingart, Printing & Electrochemical Engineering Laboratory Department of Chemical Engineering, CCNY.

If you’re curious about whether the our panels can take a beating, watch this video of our 2 Watt solar panel below. We use industrial materials for the backing of each panel and don’t skimp on the coating material (which is a fair amount of the total cost). Chances are you’ve seen solar panels that have yellowed or cracked over time. Think of these at the opposite to those panels. We’ve left panels like these out for years and they’re still producing near their spec and looking great.

These panels come to us from Voltaic Systems, makers of fine solar-powered bags and packs. These are waterproof, scratch resistant, and UV resistant. They use a high efficiency monocrystalline cell. They output 6V at 330 mA via 3.5mm x 1.3mm DC jack connector. The substrate is an aluminum / plastic composite, specifically designed to be strong and lightweight. They can easily stand up to typical outdoor use including being dropped and leaned on. They’re very high quality and suggested for projects that will be exposed to the outdoors.

• Size: 4.4″ x 5.4″ / 135mm x 1150mm
• Weight: 4 ounces / 120 grams
• Cell type: Monocrystaline
• Cell efficiency: 17%+

To connect, we suggest a 3.8mm OD/1.3mm ID DC jack

For some nifty ideas on what to do with your solar panels, check out Voltaic’s DIY page

Self-cleaning technology from Mars can keep terrestrial solar panels dust free… This is interesting, as we’ve been working with our solar projects we were wondering how large scale solar farms “dust off” the panels…

The self-cleaning technology involves deposition of a transparent, electrically sensitive material deposited on glass or a transparent plastic sheet covering the panels. Sensors monitor dust levels on the surface of the panel and energize the material when dust concentration reaches a critical level. The electric charge sends a dust-repelling wave cascading over the surface of the material, lifting away the dust and transporting it off of the screen’s edges.

Mazumder said that within two minutes, the process removes about 90 percent of the dust deposited on a solar panel and requires only a small amount of the electricity generated by the panel for cleaning operations.

This is actually not any sort of product or public project (!) – its something we designed to help me evaluate solar panels and how they act when charging batteries. Normally this requires a lot of multimeters and its a bit of a pain to do if you have to constantly change out panels. So we decided we would build a specialized tool that would assist us. Here is what we wanted!

• Portable! Its hard to test solar panels inside
• Ability to log to an SD card for long-term data analysis (to be added later)
• Keep track of the solar panel voltage
• Keep track of the battery voltage
• Keep track of how much current is going thru the panel to the charger

We figured if we had to build this, someone might find my notes useful. However, this documentation is primarily intended to demonstrate how to use the enclosure we carry in the adafruit shop.

This design is intended for ~6V panels, single Lithium Polymer cells and chargers. It can very easily be adapted to any kind of panel and charger, you’ll just need to adjust the resistor dividers and such!

Read more!

BACK IN STOCK – USB LiIon/LiPoly charger – v1.1! This is a Lithium Ion and Lithium Polymer battery charger based on the MCP73833. It uses a USB mini-B for connection to any computer or ‘USB wall adapter’. Charging is performed in three stages: first a preconditioning charge, then a constant-current fast charge and finally a constant-voltage trickle charge to keep the battery topped-up. The fast-charge current is 200mA by default, but is easily adjustable from 100mA up to 1000mA by soldering a through-hole resistor on-board. This board is great for DIY projects because it has 3 indicator LEDs – one for power, one for charging status and a third that indicates when charging is complete. Keep the battery connected to the charger and pass power through the additional JST connector using the included cable!

• Comes assembled and tested with a free bonus JST cable!
• 5V input via mini-B USB connector
• For charging single Lithium Ion/Lithium Polymer 3.7/4.2v batteries (not for older 3.6/4.1v cells)
• 200mA charge current, adjustable up to 1000mA by soldering in a resistor
• Separate JST connectors for battery and load system so batteries don’t have to be removed for charging
• Chip supports a 10K thermistor which we have stuffed as a plain 10K. For people who require temperature monitors (using high charge rates), remove the 10K and solder in the thermistor in its place
• 0.1″ (2.54mm) pads next to the JST in case you want to use terminal blocks or connect it to a breadboard
• Free 2-pin JST cable included!

Battery and USB cable not included (but they’re available in our store).

And these two books are back in stock too!

Practical Arduino (Jon Oxer & Hugh Blemings)
This book is best used for people who’ve gone through our tutorials and want more! Please note that the book does not come with any electronic parts or hardware. You’ll probably want an Arduino starter pack or similar so that you have the Arduino, USB cable, power adapter, wires, and a protoshield. Read more…

Make: Electronics (Charles Platt)
We checked out this book before putting it in the shop, its geared towards ultimate-beginners and teaches electronics starting from basic core of analog to some digital to microcontrollers. You’ll learn tools, prototyping soldering techniques, transistors, 555′s, etc. while completing useful projects. A nice and tidy intro! This book is a good accompaniment to learning microcontrollers/Arduino in that it fills the necessary electronics theory and background. Read more…

Wind Turbine Wireless Network and Power Monitor via HaD.

The purpose of this project was to provide an inexpensive communications network that does not rely on pre-existing infrastructure. Currently the system utilizes wind and solar energy to power a wifi repeater and VOIP phone. The power produced by the wind turbine and solar panel is monitored remotely using a hall-effect sensor and microcontroller.

The proposed system relies on access (through multiple repeaters if necessary) to an internet uplink in order to provide internet access. To overcome this limitation, the system could easily be expanded to be deployable anywhere through the use of a satellite phone/modem. However, the use of satellite phones would significantly increase the cost of the project. Since this project was funded by college students and a wifi network was readily accessible on campus, this was not a viable option for our prototype system.

6 x AA battery holder with 2.1mm plug – Make a portable power brick with plenty of juice! Use Alkaline AA’s for a 9V 3000-4000mAh power supply, or rechargeable NiMH for 2000mAh 7.5V supply. Either one is good for running electronics that have a 5V voltage regulator (thus requiring a 7V+ supply). Will last about 10 times longer than a 9V. Perfect for portable Arduinos! Batteries not included. Some quick soldering is required to attach the jack to the holder.

$5.00 in the Adafruit store!

So – if you want to make solar MintyBoost, here’s how –

Pick up a USB LiIon/LiPoly charger – v1.1 and Lithium Ion Polymer Battery – 1200mAh. A 1200mAh lipoly will provide as much overall power (~4.5 Wh) as 2 rechargable AA’s.

Choose from either a 1W or 2W solar panel. Either will work, if you are using the smaller panel, we suggest removing R4 and replacing it with a 6.8K (or so) resistor which will keep the lipoly charger from trying to draw too much current from the panel.

Next up, you’ll need a mini-B USB cable to sacrifice. Use the one in the shop or find one in your room.

Follow the tutorial on our site for how to splice the solar panel into the USB cable.

Finally, a MintyBoost will give you a USB 5V output! Connect the other side of the JST cable from the LiPo charger into the input of the MintyBoost.

Put the panel out in the sun and watch for the charging light to go on. then when the battery is charged up, the DONE led will be lit.

You can put all this in our new Altoids mint-sized tin!

Note: While it may most devices, this will mostly likely not work consistently with the iPhone 3Gs and/or the iPhone 4. We will have a new MintyBoost and MintyBoost “rechargeable” soon, if you need to support those two devices specifically hold off until you see these new versions of our kits on our site.

Do you see it?

from Wired:

Microsoft has come up with an amazingly obvious tweak to battery tech that should save us some headaches, as well as several trillion hours of head-scratching and peering into dark holes.

Named Instaload, the invention lets you stuff the batteries into a device any which-way you fancy, eliminating the need to read dark directional diagrams. The most impressive part is the low-tech way this is handled. Each contact in the battery compartment has both positive and negative terminals. If the fat, flat end of the battery is pressing against them, it touches the outside contact. If it is the pointy positive end then it makes contact with a slightly recessed inner contact. This, combined with some simple circuitry, makes sure the current is always running the right way.

You might be surprised that this particular company produced this incredibly simple solution to a common problem. And then you read about the complex legal restrictions, and you’re not so surprised anymore.

Products show available in the new products section!

NEW PRODUCT – USB LiIon/LiPoly charger – v1.1. This is a Lithium Ion and Lithium Polymer battery charger based on the MCP73833. It uses a USB mini-B for connection to any computer or ‘USB wall adapter’. Charging is performed in three stages: first a preconditioning charge, then a constant-current fast charge and finally a constant-voltage trickle charge to keep the battery topped-up. The fast-charge current is 200mA by default, but is easily adjustable from 100mA up to 1000mA by soldering a through-hole resistor on-board.

This board is great for DIY projects because it has 3 indicator LEDs – one for power, one for charging status and a third that indicates when charging is complete. Keep the battery connected to the charger and pass power through the additional JST connector using the included cable!

• Comes assembled and tested with a free bonus JST cable!
• 5V input via mini-B USB connector
• For charging single Lithium Ion/Lithium Polymer 3.7/4.2v batteries (not for older 3.6/4.1v cells)
• 200mA charge current, adjustable up to 1000mA by soldering in a resistor
• Separate JST connectors for battery and load system so batteries don’t have to be removed for charging
• 0.1″ (2.54mm) pads next to the JST in case you want to use terminal blocks or connect it to a breadboard
• Free 2-pin JST cable included!

Available and shipping now in the Adafruit store, $10.00 (that’s right, only $10.00) !

Please post all TECHNICAL questions up in the forums, thanks!

]]> http://www.adafruit.com/adablog/?feed=rss2&p=5440 4 http://www.adafruit.com/blog/2010/06/30/new-product-lithium-ion-polymer-battery-1200mah/ http://www.adafruit.com/blog/2010/06/30/new-product-lithium-ion-polymer-battery-1200mah/#comments Wed, 30 Jun 2010 04:00:03 +0000 adafruit http://www.adafruit.com/blog/2010/06/30/new-product-lithium-ion-polymer-battery-1200mah/

NEW PRODUCT – Lithium Ion Polymer Battery – 1200mAh. Lithium ion polymer (also known as ‘lipo’ or ‘lipoly’) batteries are thin, light and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery has a capacity of 1200mAh for a total of about 4.5 Wh.

The batteries come pre-attached with a 2-pin JST-PH connector as shown and include the necessary protection circuitry. The protection circuitry keeps the battery voltage from going to high (over-charging) or low (over-use) which means that the battery will cut-out when completely dead. It will also protect against output shorts. However, even with this protection it is very important that you only use a LiIon/LiPoly constant-voltage/constant-current charger to recharge them and at a rate of 500mA or less.

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.

• Weight: 25g
• Size: 1.35″ x 2.55″ x 0.2″ (35mm x 65mm x 5mm)
• Output: 1200mAh at 3.7V nominal

Available and shipping now, $12.00 each in the Adafruit store!

Please post all TECHNICAL questions up in the forums, thanks!

]]> http://www.adafruit.com/adablog/?feed=rss2&p=5438 4 http://www.adafruit.com/blog/2010/06/22/why-do-we-still-use-powercords/ http://www.adafruit.com/blog/2010/06/22/why-do-we-still-use-powercords/#comments Tue, 22 Jun 2010 19:48:58 +0000 johngineer http://www.adafruit.com/blog/?p=5282

An interesting piece from Wired:

It’s a good thing Nikola Tesla never figured out how to time travel, because that cord jungle behind your entertainment center would break his heart—again. It’s been more than a century since he lit incandescent bulbs wirelessly in his lab, and yet you’re still plugging into the wall.

Even your three-pronged socket looks surprised.

My three-pronged socket looks more shocked than surprised, what with all that smoke and all… oh dear. Excuse me.

]]> http://www.adafruit.com/adablog/?feed=rss2&p=5282 4 http://www.adafruit.com/blog/2010/05/28/the-power-of-batteries/ http://www.adafruit.com/blog/2010/05/28/the-power-of-batteries/#comments Fri, 28 May 2010 21:01:57 +0000 johngineer http://www.adafruit.com/blog/?p=4524

Henry Schelesinger, author of the book “The Battery: How Portable Power Sparked a Technological Revolution” gives a brief history of this most humble of devices, and suggests where new technology is headed.

via IEEE Spectrum

]]> http://www.adafruit.com/adablog/?feed=rss2&p=4524 0 http://www.adafruit.com/blog/2010/05/14/estimating-battery-charge-time-from-solar/ http://www.adafruit.com/blog/2010/05/14/estimating-battery-charge-time-from-solar/#comments Fri, 14 May 2010 16:20:55 +0000 adafruit http://www.adafruit.com/blog/2010/05/14/estimating-battery-charge-time-from-solar/

Jeff writes -

You have a 2 Watt, 6 Volt panel and a 1,000 mAh, 3.7V battery, how long does it take to completely charge? The quick and very wrong answer would be to figure out the Watt hours of the battery (3.7 * 1Ah = 3.7 Watt hours) and divide. The reality is about 2.5 times longer.

Read more!

]]> http://www.adafruit.com/adablog/?feed=rss2&p=4132 0 http://www.adafruit.com/blog/2010/03/19/from-the-forums-bb-power-supply-pot-problem/ http://www.adafruit.com/blog/2010/03/19/from-the-forums-bb-power-supply-pot-problem/#comments Fri, 19 Mar 2010 20:06:33 +0000 adafruit http://www.adafruit.com/blog/2010/03/19/from-the-forums-bb-power-supply-pot-problem/
Itsthemedication in the Adafruit forums writes -

I just put together the BB power supply, and only have 29 more to go. One reason for selecting this PS was for the adjustable voltage, i.e. I needed a STABLE 1.9 volts (don’t ask). Anyway, if anyone else is thinking about this excellent little board and needs a voltage greater than 3 I highly recommend ditching the single turn pot (very imprecise and possibly noisy as well) and replacing it with an 18 or 25 turn pot like Digikey 490-2914-ND (92 cents). The switched 3.3 and 5 volts work great by the way!


Adjustable breadboard power supply – v1.0 – This project details the design of a very low dropout adjustable power supply. A good power supply is essential to electronic projects. While there are many existing designs for adjustable power supplies, this one makes improvements that make it more useful for hobby designs.

• MIC2941 regulator has guaranteed 1.25A output
• Low dropout, only 40mV – 400mV compared to 1.25V – 2.0V for LM317. This means you can use a wider range of output voltages including generating 3.3V from as low as 3.7V (such as 3 AA’s or a lithium ion battery)!
• Short circuit and overheating protection
• Input diode to protect circuitry from negative voltages or AC power supplies.
• 2.1mm DC jack and terminal connector for voltage inputs
• Two indicator LEDs for high and low voltages
• Output selection switch to select from 3.3v, 5v and Adjustable
• Onboard potentiometer for adjusting voltage from 1.25V up to within 0.5V of the input voltage. (20V max)
• On/Off switch for entire board
• Heat sink included

Breadboard and battery clip or DC power supply is not included, you can use any DC power supply with 2.1mm plug (we have a nice one in the shop). For design documents, instructions, parts list, etc. Check out the project webpage!

]]> http://www.adafruit.com/adablog/?feed=rss2&p=3304 1 http://www.adafruit.com/blog/2009/07/24/hooray-the-breadboard-power-supply-from-adafruit/ http://www.adafruit.com/blog/2009/07/24/hooray-the-breadboard-power-supply-from-adafruit/#comments Fri, 24 Jul 2009 19:10:39 +0000 adafruit http://www.adafruit.com/blog/2009/07/24/hooray-the-breadboard-power-supply-from-adafruit/

Catbus has a nice review of our new breadboard power supply kit…

Hooray, the breadboard power supply from Adafruit is put together and working. I look forward to not clawing my face off in frustration every time I have to ******* breadboard anything requiring power.

]]> http://www.adafruit.com/adablog/?feed=rss2&p=1414 1 http://www.adafruit.com/blog/2009/07/15/adjustable-breadboard-power-supply-kit/ http://www.adafruit.com/blog/2009/07/15/adjustable-breadboard-power-supply-kit/#comments Thu, 16 Jul 2009 04:51:24 +0000 adafruit http://www.adafruit.com/blog/2009/07/15/adjustable-breadboard-power-supply-kit/

Breadboard supply A very low dropout adjustable power supply! This project details the design of a very low dropout adjustable power supply. A good power supply is essential to electronic projects. While there are many existing designs for adjustable power supplies, this one makes improvements that make it more useful for hobby designs
• MIC2941 regulator has guaranteed 1.25A output
• Low dropout, only 40mV – 400mV compared to 1.25V – 2.0V for LM317. This means you can use a wider range of output voltages including generating 3.3V from as low as 3.7V (such as 3 AA’s or a lithium ion battery)!
• Short circuit and overheating protection
• Input diode to protect circuitry from negative voltages or AC power supplies.
• 2.1mm DC jack and terminal connector for voltage inputs
• Two indicator LEDs for high and low voltages
• Output selection switch to select from 3.3v, 5v and Adjustable
• Onboard potentiometer for adjusting voltage from 1.25V up to within 0.5V of the input voltage. (20V max)
• On/Off switch for entire board
• Heat sink included
• Breadboard and battery clip or DC power supply is not included, you can use any DC power supply with 2.1mm plug (we have a nice one in the shop).

For design documents, instructions, parts list, etc. Check out the project webpage! And pick up one up at the Adafruit store!

]]> http://www.adafruit.com/adablog/?feed=rss2&p=1384 6 http://www.adafruit.com/blog/2006/02/28/specifying-an-op-amp/ http://www.adafruit.com/blog/2006/02/28/specifying-an-op-amp/#comments Wed, 01 Mar 2006 01:02:33 +0000 ladyada http://www.ladyada.net/rant/?p=8 So you need an op amp…and you can’t use just any generic op amp because of certain requirements. For example, a low supply voltage (<10V), high frequency, low noise, low power requirements etc.

Finding the right op amp isn't hard, here is an example of how to go about your search. For this example, I will specify the op amp to be used for the circuit from last week, a tape-head preamplifier. The schematic used an OP37. However, this op amp requires a 8V powersupply, and I'm going to be using only a 3V battery. Also, its good to see if there are any cheaper alternatives.

Specifically, the op amp is going to amplify a 10uV peak-to-peak signal by 1000 (up to 10mVpp). The op amp should work from 20Hz to 20KHz (optimal audio range), & be not too tough to solder.
First, write down what the constraints are:

• Has to run on a 3V “single supply” and we’ll have our DC offset at 1.5V
• Input offset voltage (Vos) must be < 1mV. At worst, at x1000 thats a +-1V offset at the output: as low as .5V or as high as 2.5V.
• Since we need to handle such a large swing, it should be rail-to-rail to within .2V of the rails to give us space.
• 1000 gain at 20KHz means the gain bandwidth (GBW) must be > 20MHz (in reality it can be much lower because the tape probably isnt good enough to record past 12KHz)
• Since our input signal is 10uV then (at worst) we want to have less than 5% noise (which isn’t so good but we’re willing to have poor quality audio). 5% of 10uV = 500nV. 500nV/sqrt(20000) = 3.5nVrtHz noise figure.
• Package should be SOIC for easy soldering
• Low power is nice but not -that- necessary, maybe < 10mA
• Low price! Must be under $2 at quantity 100, the lower the better

Stuff we don’t care about:

• Operating temperature
• Slew rate (at 10mV and 20KHz, it can be really slow)

The OP37, for comparison, has 12MHz GBW, requires 8V power supply, not rail-to-rail, Vos = 0.03mV, and noise figure of 3.2nVrtHz. So: great offset, great noise, so-so bandwidth and incompatible power requirements.

Lets go to TI and see what they have to offer. Select >=16MHz GBW, rail-to-rail and 8-SOIC package. The only chip they’ve got is the OPA350.

Now lets try National. Their system is a little tougher to use: click on 1mA offset first, which will pare down the options to 5 items, none of which are SOIC. You’ll notice national doesnt have a very good selection of low noise, ~20MHz op amps.

Next, we go to Analog Devices. Enter in package = SOIC, Vcc-Vee = 3V, noise <= 5nVrtHz, Vos <= 1mV then sort by price. The AD8655 looks good, a little noiser but nearly half the price.

Checking STMicro (click on “low noise”) they don’t have anything that runs on 3V.

Linear Technologies has a bunch of incredibly low noise op amps, at extraordinary bandwidths, but they’re rather expensive, at least $3 which is outside of our budget.

Maxim has a few good options (sort by noise, then compare all of the ones <5nVrtHz, then select out the ones that cost more than $2, then select only the ones that work from a single 2.7V supply & single package & > 20MHz GBW, that leaves the MAX4488.

Part	Noise (nVrtHz)	GBW (MHz)	Vos (mV)	Iq (mA)	$/qty 100
OP37	3.2	12	0.03	5.5	$1.07
OPA350	5	38	0.5	7.5	$1.73
AD8655	4	29	0.05	4.5	$0.88
MAX4488	4.5	42	0.75	2.5	$0.72

There are a couple other manufacturers but we’ve covered the most common. So let’s stop here. The OPA350 is clearly not a good choice, it’s the most expensive, noisiest and most power-hungry. So we’ll just ignore that, leaving the AD8655 and MAX4488. Now its just a comparison between price, power and noise. Since our noise figure is already higher than we’d like, I’ll place priority on that: the price difference is pretty small and power isn’t a huge priority.

Finally, we have chosen the AD8655. Yay Analog Devices!

]]> http://www.adafruit.com/adablog/?feed=rss2&p=8 2