You guys might want to update the mintyboost...

Ideas and questions about MintyBoost kits

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
moeburn
 
Posts: 34
Joined: Fri Jul 19, 2013 12:09 am

You guys might want to update the mintyboost...

Post by moeburn »

Just a heads up... I'm not going to link to it, because I like you guys, and what you do here. But if someone knows what to look for, you can easily find a premade circuit on an online bidding site for less than $5 with a built in USB socket, and all you have to do is connect 3 AA's to it, and you can charge up to 1.5A. I can actually charge my Atrix with it. I can even charge the officially unsupported iPad and other high drain tablets (albeit not very quickly :D).

I know you guys picked the highest current DIP-socket DC-DC boost converter that you could find, heck the highest one I could find. But, if you want to compete with these ones, and are willing to put a few extra labour hours into the production of the kit, you could get the 1.5A DC-5vDC boost converter in the little SOIC package, and pre-solder it to an SOIC-DIP adapter, like this one, or this one, that way the consumer could still easily solder on and attach to a DIP socket themselves.

Just thought I'd share the love I have for my new 1.5A AA-USB charger :)

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: You guys might want to update the mintyboost...

Post by adafruit_support_bill »

Thanks for the suggestion! :D

User avatar
moeburn
 
Posts: 34
Joined: Fri Jul 19, 2013 12:09 am

Re: You guys might want to update the mintyboost...

Post by moeburn »

Oh, and just thought I'd mention, it works just fine with 2 AAs, since that's the appeal of your current small design, but the current output is limited by the input voltage, so you don't get more than about 500mA out of two AAs. For the up to 1.5A output, you need to use 3. Otherwise that poor DC converter would not only have 1.5A going through it, but also all the heat loss generated by having too high a delta-V.

Illum3415
 
Posts: 6
Joined: Sun May 11, 2014 12:09 pm

Re: You guys might want to update the mintyboost...

Post by Illum3415 »

Hello Moeburn,

There is a flaw in your idea, I would like to point out that many of the surface mounted components, especially of the step-up topology, operate at an oscillating frequency in excess of 900KHz, even some up to 3MHz. At these frequencies, PCB design is Über-critical and certain traces must be kept as short as possible. DIP adapters, while mechanically sound, electrically makes the integrated circuit run the extra mile, and they likely may refuse to switch at all. It would be difficult in my opinion to rely on the inherent batch differences for the successful implementation of working configurations produced as a kit. DIP-SMT adapters are more ideal for devices that do not oscillate at all, SMT passives for BJTs or FETs, logic ICs, etc. for example. But as always, they are mostly prototyping tools and cannot replace a dedicated "ground up" PCB design. :)

User avatar
nsayer
 
Posts: 59
Joined: Thu Aug 08, 2013 10:45 am

Re: You guys might want to update the mintyboost...

Post by nsayer »

You can get boost converters that operate at lower switching frequencies. The NCP1450 is a PWM controller that works at a fixed 180 kHz, for instance, and uses an external MOSFET, so (in principle) could be used for very high powered designs. I have a preliminary design for a "MicroBoost" designed this way in at OSHPark right now. I only rated my design for 500 mA, but I think it would only take upgrading the parts in the high current path and swapping out the D+/- resistor dividers to make it go up to 1.5A or even more.

Locked
Please be positive and constructive with your questions and comments.

Return to “MintyBoost”