--- crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68
On Tue, Dec 20, 2016 at 8:28 AM, mike.valk@gmail.com mike.valk@gmail.com wrote:
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 ;-).
can't remember the P/N, it's in the PDF, http://hands.com/~lkcl/eoma/laptop_15in/pcb1
I presume a "dognut" type plug?
it's not the 5.5mm one, it's too big.
If so, of what dimensions and which polarity or does it have a polarity switcher or at least a polarity safety?
pin positive. don't know.
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.
too much involved in the way of electronics.
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.
7-19V on DC jack. standard voltage on OTG port (4.somethingsomething to 5.somethingsomething)
But if I understood correctly the EOMA-68 card accepts power over the OTG port and passes through, any surplus, to the housing.
they're hard-wired on the EOMA68-A20. it's not a matter of "surplus", there's no way there's enough current to power the Card *and* the laptop - the currently limit is something like 450mA for standard OTG.
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.
all correct.
Standard USB only delivers 5V*500mA= 2.5W. But various options are allowed apparently. https://en.wikipedia.org/wiki/USB#Power
not with the AXP209 (the PMIC on the EOMA68-A20) they're not.
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%.
NO.
4A @ 5V, absolute max 20A. look up the bq24193 datasheet.
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.
12v is within acceptable range of 7-19v, yes.
l.