2016-12-19 22:56 GMT+01:00 Luke Kenneth Casson Leighton <lkcl@lkcl.net>:
---
crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Mon, Dec 19, 2016 at 9:45 PM, Jonathan Frederickson
<silverskullpsu@gmail.com> wrote:
> Hey, I have a few questions about the laptop housing.
>
> - How does one connect it to power?

 standard DC jack, anywhere between 7 and 19v.

I've never found a standard DC jack ;-). I presume a "dognut" type plug? If so, of what dimensions and which polarity or does it have a polarity switcher or at least a polarity safety? 

I think the USB-C connector is going to be the first "standard" "universal" charging connector. Standard USB-C cable should be able to provide 60W (20V*3A) and power cables 100W (20V*5A). But not "ominous" enough yet.


> Can it be powered over USB

 powered no, charged, yes.  current limit on the OTG port.

Well if the input minimum is 7V than neither. 

But if I understood correctly the EOMA-68 card accepts power over the OTG port and passes through, any surplus, to the housing. Thus slowing down the battery drainage of the housing(laptop/tablet). And charging, although slow, when the housing is turned off. And a little faster when both, housing and card, are turned off.

Standard USB only delivers 5V*500mA= 2.5W. But various options are allowed apparently. https://en.wikipedia.org/wiki/USB#Power
 

>  or does
> it require a specific AC adapter?

 no.  min 4A is best, but if you're prepared to reprogram the
STM32F072 yourself you could get away with less

4A on the output side I presume so 19v*4A=76W, So a 95W power supply with 80% efficiency (90*80%=76). Or 85W at 90%.
 

> I have a portable solar array with a
> battery pack that can charge portable devices over USB, and I'm trying
> to work out whether or not I'll be able to power the laptop from it.

If it has 12v out that would be your best bet I guess.