John Larkin wrote:
> On Wed, 30 Mar 2022 16:08:04 -0700 (PDT), whit3rd <whit3rd@gmail.com>
> wrote:
>
>> On Wednesday, March 30, 2022 at 12:27:44 PM UTC-7, John Larkin wrote:
>>
>>> I'd like to use a laptop for a control application in an unattended
>>> location, instead of a big PC and a UPS. But a PC bios can usually be
>>> set up to restart the PC after a hard power failure, and it seems like
>>> laptops can't do that for some reason. I'd love to find one that does.
>>
>> MacOS laptops can be scheduled for turn-on and/or off once a day, with
>> the 'energy saver' settings. UPS connection sometimes adds options, too.
>
> I need a Windows machine. If power fails for a full day maybe, a
> laptop will run out of battery power and shut down, but can't be set
> up to restart when power comes back. At least none that I can find.
>
> Strange.
>
> Maybe some laptops can be set up to deep-sleep when batteries get low,
> but wake up when power comes back. If one could ride out a few days
> that way on remaining battery power, it would be OK.
>
>
>

IIRC a lot of them have wake-on-LAN in the BIOS, so you might be able to
apply some router hackery to the problem. (I'm a devoted user of legacy
BIOS, so I don't know a lot about UEFI things.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Thursday, 31 March 2022 at 18:18:44 UTC+1, Phil Hobbs wrote:
> John Larkin wrote:
> > On Wed, 30 Mar 2022 16:08:04 -0700 (PDT), whit3rd <whi...@gmail.com>
> > wrote:
> >
> >> On Wednesday, March 30, 2022 at 12:27:44 PM UTC-7, John Larkin wrote:
> >>
> >>> I'd like to use a laptop for a control application in an unattended
> >>> location, instead of a big PC and a UPS. But a PC bios can usually be
> >>> set up to restart the PC after a hard power failure, and it seems like
> >>> laptops can't do that for some reason. I'd love to find one that does.
> >>
> >> MacOS laptops can be scheduled for turn-on and/or off once a day, with
> >> the 'energy saver' settings. UPS connection sometimes adds options, too.
> >
> > I need a Windows machine. If power fails for a full day maybe, a
> > laptop will run out of battery power and shut down, but can't be set
> > up to restart when power comes back. At least none that I can find.
> >
> > Strange.
> >
> > Maybe some laptops can be set up to deep-sleep when batteries get low,
> > but wake up when power comes back. If one could ride out a few days
> > that way on remaining battery power, it would be OK.
> >
> >
> >
> IIRC a lot of them have wake-on-LAN in the BIOS, so you might be able to
> apply some router hackery to the problem. (I'm a devoted user of legacy
> BIOS, so I don't know a lot about UEFI things.)
>

If laptops don't do what is needed, there are a lot of mini-itx motherboards
around that can be configured to auto restart and which have a single 12V dc
input. If the disc drives don't use 12V, (SSDs and 2.5inch spinning drives don't)
then they will usually cope with quite a wide variation in input voltage as the 12V
input goes to a buck converter to generate 5V and then the other lower voltages
needed. Some industrial motherboards are even rated for inputs of up to about
19Vdc. This means that a 12V SLA battery would make a very efficient UPS
for such a motherboard. I have used ASRock IMB-150/151 motherboards in this way.
They are rated for input voltages of 9-19V, but I think the TI buck converter chip
they use is actually good for operation with up to 25V.
John

John Walliker wrote:
> On Thursday, 31 March 2022 at 18:18:44 UTC+1, Phil Hobbs wrote:
>> John Larkin wrote:
>>> On Wed, 30 Mar 2022 16:08:04 -0700 (PDT), whit3rd <whi...@gmail.com>
>>> wrote:
>>>
>>>> On Wednesday, March 30, 2022 at 12:27:44 PM UTC-7, John Larkin wrote:
>>>>
>>>>> I'd like to use a laptop for a control application in an unattended
>>>>> location, instead of a big PC and a UPS. But a PC bios can usually be
>>>>> set up to restart the PC after a hard power failure, and it seems like
>>>>> laptops can't do that for some reason. I'd love to find one that does.
>>>>
>>>> MacOS laptops can be scheduled for turn-on and/or off once a day, with
>>>> the 'energy saver' settings. UPS connection sometimes adds options, too.
>>>
>>> I need a Windows machine. If power fails for a full day maybe, a
>>> laptop will run out of battery power and shut down, but can't be set
>>> up to restart when power comes back. At least none that I can find.
>>>
>>> Strange.
>>>
>>> Maybe some laptops can be set up to deep-sleep when batteries get low,
>>> but wake up when power comes back. If one could ride out a few days
>>> that way on remaining battery power, it would be OK.
>>>
>>>
>>>
>> IIRC a lot of them have wake-on-LAN in the BIOS, so you might be able to
>> apply some router hackery to the problem. (I'm a devoted user of legacy
>> BIOS, so I don't know a lot about UEFI things.)
>>
>
> If laptops don't do what is needed, there are a lot of mini-itx motherboards
> around that can be configured to auto restart and which have a single 12V dc
> input. If the disc drives don't use 12V, (SSDs and 2.5inch spinning drives don't)
> then they will usually cope with quite a wide variation in input voltage as the 12V
> input goes to a buck converter to generate 5V and then the other lower voltages
> needed. Some industrial motherboards are even rated for inputs of up to about
> 19Vdc. This means that a 12V SLA battery would make a very efficient UPS
> for such a motherboard. I have used ASRock IMB-150/151 motherboards in this way.
> They are rated for input voltages of 9-19V, but I think the TI buck converter chip
> they use is actually good for operation with up to 25V.
> John
>

It's pretty attractive to use old laptops for this sort of job--I use
them as NASes, for instance. You get them from eBay for $100 or so,
replace the HDD, and you're done. (I run Linux on them, so there are
no huge issues with reinstalling the OS.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On Tuesday, March 29, 2022 at 10:25:36 PM UTC-4, Don Y wrote:
> From time to time, we seem to experience a power "glitch", once a
> day, at roughly the same time -- usually ~3AM. (but, not every day...
> just "periods" when it manifests followed by periods where it is
> completely absent).
>
> It's not a problem, for the most part, as everything is on UPSs, here
> (the microwave oven seems to complain the most as it isn't on a UPS
> and its damn clock often resets -- I long for the day when appliances
> have synchronized clocks or NO clocks!!!)
>
> I assume this is some sort of switching transient that affects the
> entire city (?) -- or, at least large portions of it.
>
> (our services are below grade so not likely caused by something
> physically interfering with the transmission lines)
>
> I'm turning my attention to the design of the power systems for
> my current project and figure it would be prudent to put some
> line-monitoring capabilities into it (if only to let it anticipate
> such problems and plan ahead).
>
> So, the questions are:
> - how often to sample (to be able to catch transient events)
> - maximum peak likely to be encountered
>
> [Of course, I have to anticipate what the power conditions are
> likely to be in other parts of the market (US consumer and,
> separately, commercial/industrial) and not just rely on my own
> observations.]
>
> I'm tempted to buy a line monitor just to see what they've done
> (in terms of hardware interface; the signal processing software
> won't be a problem). Recommendations? (again, two/three different
> markets, as above)
If I understand correctly what you are trying to do, I'd suggest applying Nyquist criteria for waveform re-construction....
https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
understanding the highest frequency in the sampled signal is the key.
J

On 3/31/2022 5:10 PM, Three Jeeps wrote:
> On Tuesday, March 29, 2022 at 10:25:36 PM UTC-4, Don Y wrote:
>> From time to time, we seem to experience a power "glitch", once a
>> day, at roughly the same time -- usually ~3AM. (but, not every day...
>> just "periods" when it manifests followed by periods where it is
>> completely absent).
>>
>> It's not a problem, for the most part, as everything is on UPSs, here
>> (the microwave oven seems to complain the most as it isn't on a UPS
>> and its damn clock often resets -- I long for the day when appliances
>> have synchronized clocks or NO clocks!!!)
>>
>> I assume this is some sort of switching transient that affects the
>> entire city (?) -- or, at least large portions of it.
>>
>> (our services are below grade so not likely caused by something
>> physically interfering with the transmission lines)
>>
>> I'm turning my attention to the design of the power systems for
>> my current project and figure it would be prudent to put some
>> line-monitoring capabilities into it (if only to let it anticipate
>> such problems and plan ahead).
>>
>> So, the questions are:
>> - how often to sample (to be able to catch transient events)
>> - maximum peak likely to be encountered
>>
>> [Of course, I have to anticipate what the power conditions are
>> likely to be in other parts of the market (US consumer and,
>> separately, commercial/industrial) and not just rely on my own
>> observations.]
>>
>> I'm tempted to buy a line monitor just to see what they've done
>> (in terms of hardware interface; the signal processing software
>> won't be a problem). Recommendations? (again, two/three different
>> markets, as above)
> If I understand correctly what you are trying to do, I'd suggest applying Nyquist criteria for waveform re-construction....
> https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
> understanding the highest frequency in the sampled signal is the key.

That's the essence of the question. *Knowing* what the line can look like
and *which* aspects of the waveform carry information pertinent to making these
sorts of decisions. Capturing the "entire" waveform may not be essential if
it doesn't "add value" to any deductive process (e.g., simply noting the
magnitude of the highest peak (captured asynchronously) might reveal more
information for less effort than trying to sample it "continuously".