The United States Computer Emergency Response Team (US-CERT) has warned that the software included in the Energizer DUO USB battery charger contains a backdoor that allows unauthorized remote system access. In an advisory, the US-CERT warned that he installer for the Energizer DUO software places the file UsbCharger.dll in the application’s directory and Arucer.dll in the Windows system32 directory. An attacker is able to remotely control a system, including the ability to list directories, send and receive files, and execute programs. The backdoor operates with the privileges of the logged-on user.
We updated MintyBoost FAQ with new resistor values – We destroyed an Apple USB charger and desoldered the 0402’s to get a precise measurement – also x-referenced. So this should be the final chapter in the story!
If you’re using the iPhone 3Gs with a Mintyboostwe have added a note to the FAQ that has the precise resistor setup you would want to use if you’re going to mod your kit.
Just a note to say the MintyBoost charges my B&N nook eReader. Given the runtime claims from B&N are *cough* optimistic, the minty should come in handy when camping.
On a related note, how many electronics hobbyists who read our blog have a Kindle, nook, Sony reader, or any e-ink reader?
A wood-machinable or printable enclosure for the MintyBoost. Designed to fit the Adafruit kit’s dimensions, with a vacuum formed lid that slides on for access to the batteries.
For many small projects, its cheaper and easier to DIY a boost converter than to buy a specialty chip. DIY converters are usually not as efficient but they’re quick & cheap!
The above schematic section shows how I designed a 30-60V vacuum fluorescent tube display driven from a microcontroller pin.
Tubes such as VFDs, Nixies, Decatrons, etc require high voltage to light the gas in the tube. In order to reduce cost, we use a microconrtoller to make a boost converter and avoid paying $5 for a seperate chip. We can do this because we don’t need a precision output and the current draw is mostly constant. The boost regulator is run open-loop there is no feedback resistor divider as it isn’t necessary as long as the input voltage is within a reasonable range…
The microcontroller runs at 8MHz so the 8-bit PWM output is 31250 Hz. The inductor and output capacitor is calculated below. The diode is a standard Schottkey type. The switch just has to be able to handle the max voltage plus some for safety. Note that this design is meant for ’static’ output currents, not for variable current draw designs. There is no feedback and its very approximate! This is not for precision electronics!
The boost circuit works by connecting the power inductor L1 to ground that current can flow through it by turning on Q2. After a little bit of time, we disconnect the from ground (by turning off Q2) this means that there is no longer a path for the current in L1 to flow to ground. When this happens, the voltage across the inductor increases (this is the electric property of inductors) and charges up C6 . When the voltage increases to the level we want it to be (30V+) we turn on Q2 again which allows the current in L1 to flow back to ground. If we do this fast enough, and C6 large enough, the voltage on C6 is smoothed out and we get a nice steady high voltage.
The timing of turning off/on Q2 allows us to modify the output voltage. Normally there is a feedback resistor to the microcontroller but it is not here because we are running it open-loop. To drive Q2 we use the PWM output from the microcontroller and adjust the duty cycle to vary brightness.
These sorts of designs can be easily made with a 555, once you have the PWM output, connect it up to Q2! For this simple calculator, enter in the freqency, voltage ranges and current ranges and the duty cycle, inductor and current requirements will be displayed!
Today I was finished with a little project I have been working on. It took about two days of internet searching and ideas The result is a modified USB cable with a SE Fastport connector, I have tested it with my SE phone C510i and it works great with Mintyboost !! With one set of batteries I got approximately a 12 % increase of the battery life, it took about an half an hour to get that.
I just built a MintyBoost and it works perfectly with both a Flip Mino and a Flip MinoHD pocket video camera. The white light on the camera’s USB connector indicates that it’s receiving power…
“The problem is, with an iPod Touch or an iPhone, the battery in an iPhone is so big that it will deplete the batteries [in the Minty Boost] and you’ll only get half a charge,” he explained.
To improve upon the Minty Boost, Kelty replaced the AA batteries with a rechargeable lithium polymer battery and added a small solar panel. The solar panel recharges the internal battery, which in turn recharges the iPhone.
“The idea is that you can leave this out in the sun during the day while you’re using your phone, or whatever device, and at night time, plug your phone into it and you’re good to go,” Kelty said.
This was my first kit and my second attempt at soldering and it worked first try so I would consider that a big success. I had already put it all together before realizing that I didn’t have any pix of the underside of the PCB. Just as well, it’s functional but not pretty.
One thing I changed from the instructions was to use a dremel tool to make the hole for the USB port instead of using snips to cut through the top of the case. I think it looks better and it should be more sturdy.
Looking forward to more electronics kits, this one was a breeze. I need to resurrect one of my old laptops and move it out the garage. The kit instructions were online only and I don’t want to take my good laptop out to the garage amid the dirt/metal filings/sawdust. I ended up printing out the main soldering instructions.
Thanks LadyAda and Adafruit Industries for a great starter kit.
. The MintyBoost will not install software and not trojan your computer.
The result is a modified USB cable with a SE Fastport connector, I have tested it with my SE phone C510i and it works great with 
