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Maybe its worth looking at how arc fault interrupters detect arcing?
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.
On Wed, 30 Mar 2022 07:22:43 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:
The power network over here switches, sometimes 2 times a day, between networks it seems.
This causes a short (usually less than a second) power dip.
UPS takes care of that as far as computers go.
Laptop has its on battery and will run much longer,
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.
On Wednesday, March 30, 2022 at 7:11:29 PM UTC-7, Don Y wrote:
On 3/30/2022 2:58 PM, whit3rd wrote:
So, the questions are:
- how often to sample (to be able to catch transient events)
- maximum peak likely to be encountered
... I\'d think to log also any deviation from
\'normal\' 120 (or 100) zero crossings per second. Maybe store a few dozen
cycles before and after an \'event\', gives you an idea of the transient. Motor
starts without zero-voltage-switching have dimmed my lights and
several times rebooted a Linux box exactly when I hear the buzzsaw.
Hmmm... I hadn\'t thought of keeping much \"context\".
The FNET folks sample at ~1.5KHz (I don\'t recall the precision) and try to
detect anomalies in the grid by coordinating observations from geographically
dispersed measurement stations. I assume some of their algorithms could be
applied to local \"single observation\" points.
Finding someone else\'s algorithms would be a good idea;
I belatedly realize that a bit
of powerline signalling is done near zero crossings, and maybe timing peaks then
resetting the peak detector at zero crossings is a better way to go. A powerline
45 MHz Ethernet link wouldn\'t look benign.
On a sunny day (Wed, 30 Mar 2022 12:27:32 -0700) it happened John Larkin
jlarkin@highland_atwork_technology.com> wrote in
4eb94hd6nturau50ev7muckgefj21h6nh0@4ax.com>:
On Wed, 30 Mar 2022 07:22:43 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:
The power network over here switches, sometimes 2 times a day, between networks it seems.
This causes a short (usually less than a second) power dip.
UPS takes care of that as far as computers go.
Laptop has its on battery and will run much longer,
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.
Is that not mainly a BIOS config?
On Thu, 31 Mar 2022 05:40:56 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:
On a sunny day (Wed, 30 Mar 2022 12:27:32 -0700) it happened John Larkin
jlarkin@highland_atwork_technology.com> wrote in
4eb94hd6nturau50ev7muckgefj21h6nh0@4ax.com>:
On Wed, 30 Mar 2022 07:22:43 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:
The power network over here switches, sometimes 2 times a day, between networks it seems.
This causes a short (usually less than a second) power dip.
UPS takes care of that as far as computers go.
Laptop has its on battery and will run much longer,
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.
Is that not mainly a BIOS config?
Yes. Some big PCs have the powerup boot option in their BIOS, some
don\'t. I\'ve not found a laptop that does.
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.
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.)
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
If I understand correctly what you are trying to do, I\'d suggest applying Nyquist criteria for waveform re-construction....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)
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.