Hey, I have a few questions about the laptop housing.
- How does one connect it to power? Can it be powered over USB or does it require a specific AC adapter? 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.
- What's the average power draw of the laptop housing with an EOMA68-A20 card? If my rough calculations are correct, I think it should be around 6.25-8.3 W? (Looking into CPU power specs has given me quite a bit of respect for Intel's engineers; it's amazing that modern laptops are able to do so much with so little power.)
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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.
Can it be powered over USB
powered no, charged, yes. current limit on the OTG port.
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
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.
- What's the average power draw of the laptop housing with an
EOMA68-A20 card?
don't know. max is 15W
If my rough calculations are correct, I think it should be around 6.25-8.3 W?
mmm LCD is around 4. if you play an audio file at full volume it'll take another 3W.
(Looking into CPU power specs has given me quite a bit of respect for Intel's engineers; it's amazing that modern laptops are able to do so much with so little power.)
yeah... :)
mmm LCD is around 4. if you play an audio file at full volume it'll take another 3W.
Oh interesting. If that's representative of other similar LCDs (and I suspect it is) that explains why we don't really see laptops with e.g. 24-hour battery life regardless of how little power the CPU uses.
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On Mon, Dec 19, 2016 at 11:19 PM, Jonathan Frederickson silverskullpsu@gmail.com wrote:
mmm LCD is around 4. if you play an audio file at full volume it'll take another 3W.
Oh interesting. If that's representative of other similar LCDs (and I suspect it is) that explains why we don't really see laptops with e.g. 24-hour battery life regardless of how little power the CPU uses.
they're usually much much worse than that, and of course it goes up on a square law. A 7in 1024x600 can be as little as 1.5 watts. 9in maybe 2.5. this 15.6in 1366x768, it's very unusuall in that you can run it at only 30hz and thus halve the power consumption of the electronics part (at least), also because it's a lower pixel refresh rate (because there's less pixels, duh) it's also lower power.
l.
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.
This is a bit off-topic, but I think you're confusing "ominous" with "ubiquitous". "Ominous" means it foreshadows evil, or otherwise exhibits a bad omen.
https://www.merriam-webster.com/dictionary/ominous
If anything, the only connectors that are ominous are the proprietary ones!
2016-12-20 14:27 GMT+01:00 Julie Marchant onpon4@riseup.net:
This is a bit off-topic, but I think you're confusing "ominous" with "ubiquitous". "Ominous" means it foreshadows evil, or otherwise exhibits a bad omen.
https://www.merriam-webster.com/dictionary/ominous
I stand corrected. Thank you.
If anything, the only connectors that are ominous are the proprietary ones!
Indeed
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On Tue, Dec 20, 2016 at 1:27 PM, Julie Marchant onpon4@riseup.net wrote:
This is a bit off-topic, but I think you're confusing "ominous" with "ubiquitous". "Ominous" means it foreshadows evil, or otherwise exhibits a bad omen.
*dramatic-drum-roll*... :)
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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.
On December 21, 2016 4:52:47 AM GMT+01:00, Luke Kenneth Casson Leighton lkcl@lkcl.net wrote:
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
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.
I think I found it: J7 in http://hands.com/~lkcl/eoma/laptop_15in/pcb3/laptop_15in_PCB3_rev2_1.pdf According to the bom it's "4.4mm Jack, 1.65mm Pin, Right-Angle, SMT, 5A Rating"
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On Wed, Dec 21, 2016 at 6:51 AM, raphael.melotte@gmail.com wrote:
it's not the 5.5mm one, it's too big.
I think I found it: J7 in http://hands.com/~lkcl/eoma/laptop_15in/pcb3/laptop_15in_PCB3_rev2_1.pdf According to the bom it's "4.4mm Jack, 1.65mm Pin, Right-Angle, SMT, 5A Rating"
that's the one, thanks raphael. it's rated for 5A so can do the job. had to use 4.4mm because of the height clearance being restricted to 6mm or so. the standard 5mm jack (2.1mm centre-pin) is too high.
l.
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