The BoostMini is a 5 volt power supply for use with microcontrollers, hobby electronics, and USB powered equipment. It is based on a step-up voltage converter circuit. This design uses a 3 volts input from two AA-batteries, but you can customize the project to use any kind of battery, AAA, C, D, coin cell, or lithium.
The output voltage remains constant even as the batteries drain.
With 3 volts supplied, it can deliver approximately 340mA at 5V. That is 1.7 watts of power, or the equivalent of running your 5 volts through only 15 ohms of resistance. You can use a lower resistant circuit (even short circuit), but the IC is internally protected and will not supply more. (Note, more amperage is possible, but you have to increase the incoming voltage.)
All of these circuits have been redesigned for maximum power efficiency. We are including on/off switches and battery cases for all pledge levels. You supply your own batteries.
Why start this project?
I learned electronics on my own by building projects and always trying new ideas. I found that most battery powered projects depended on 9 volt batteries. They used a voltage regulators like the 7805 to lower the voltage to 5 volts, and in the process wasted half of the power as heat.
I wanted something more efficient and could use AA batteries. This circuit does both.The chart below summarizes the difference. See my video for more information http://youtu.be/JVmpIO1RbWI
My other goal was to create a kit that uses surface mounted devices, SMD, instead of through hole components. This kit uses mostly the larger 1206 style components and larger. The booster IC is a little more challenging (SOT23-6 package), but it only has six pins, so it is only a little extra work.
Recently, I used one of my development kits to teach myself how to do hot-air reflow soldering with lead-free solder paste. It is pretty easy and makes assembling this kit a snap. Just another reason for you to save some money and build it yourself.
I will post information on how to make a solder mask and a pdf of the required image(s) when the campaign ends
How Do I Pledge?
We need your help to get enough orders to make a small production batch. Each pledge level is for a different item or combination of items. If you want more of one item or you want two different items. Then you add the two or three together and pledge that amount. We'll get the details from you at the end of the campaign before we ship.
Where Can You Learn More?
I have made several videos available on YouTube, and I have a Facebook page with more photographs and information.
Here are some of the links. If you like the project please like either our Facebook page or Youtube videos. We need your help to spread the word about this project.
Intro to the BoostMini
BoostMini versus 7805
After I built my first version of the BoostMini, I wanted to add it to other circuits.
First there was the idea to get this circuit in a different voltage, 3.3V instead of 5V. This could be powered from a single AA battery. They would be good for low voltage microprocessor circuits, and LEDs.
The second idea is still mostly a prototype. I connected a lower voltage BoostMini to a single white led. It can runs for days. I think it would make a basic night light, one that can be use with old/drained batteries instead of fresh batteries. The prototype will be easy to combine onto one board for DIY assembly.
Finally there was a bare bones Arduino clone. I had a bare bones Arduino that was taking up space on a breadboard so I design a circuit to hold it. Nothing fancy but it is an Arduino that is powered from AA-batteries. The maximum power needed for an Arduino is 250mA, so it works well with this power supply in my tests.
I will offer the triple pack in a second configuration at 3.3 volts, excluding the BoostMiniUSB (USB has to be 5 volts). I hope there are a few who would like the lower voltage option.
I will also offer a maximum pack that will include the two new Boost circuits. Since the BoostNiteLite and Boostduino are new they have a later shipping date. If you pledge for this option, then you will get the regular boards sent early. When the other two are ready, you'll get a second shipment with the new boards.
Risks and challenges
The challenge is to shift from prototype to production. I set the funding at a level I have estimated will be enough to pay for fabrication. There could be a few surprises if I get a batch of bad boards, or assembly costs are off. I have done the best I can to get quotes before starting, but things can pop up that were not expected.Learn about accountability on Kickstarter
- (10 days)