[Hackupy-discuss] USB Chargers

[miloh]

On Mon, Dec 5, 2011 at 4:55 AM, Akiba <akiba at freaklabs.org> wrote:

> ** **
>
> Sorry about the down time. Caught a nasty bout of bronchitis for the past
> few weeks. ****
>
> Regarding chargers, we (Tokyo Hackerspace) can help acquire the DC/DC
> converters from Akizuki. The schematic should also be modified so that the
> particular DC/DC converter is replaced with something more readily
> available say from Digikey or via a DC/DC switcher and some discrete parts.
> ****
>
> **
>



Just getting over a bad case of drywall throat myself.

Great, we will test these out and be in touch for more Akizuki's if we want
more!

Just as an exercise though, I'm curious about replacement parts for the
Akizuki buck.  I haven't looked for other replacements, but I think the
monolithic IC with a heat sink solution should be targeted around $3 to
match the Akizuki. Is this unreasonable here?  Any way to get the price to
$3 for small orders the a 20W-30W buck + heat sink? Linear has nice
parametric product finders
http://www.linear.com/products/step-down_(buck)_regulators  Maybe this
board as is could be used with breakout boards for parts easily sourced in
different areas of the world.

USB charge currents will go higher than 1A for some devices, right? I know
other folks are more up-to-date on the issue of typical charge currents for
usb connected devices, but with 4 ports available on the board, perhaps we
should look for something with a 4A or greater supply capability.

What can we do to further differentiate this from existing COTS hardware?
 Being kit based is great in of itself, it gives folks something to spend
some time learning about. Having options for easily sourced cases (abs or
pvc pipe),  or unique and personalized case (laser cut custom
hacupyEnclosures ) is good also. Maybe the road heads towards changing the
pcb design in subsequent versions to include atypical features like a
uc+piezo alarm, exposed pcb for alligator clip jumpers, or more...

-rma
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