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Turn on computer using power strip



 
 
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  #1  
Old July 21st 18, 05:10 AM posted to microsoft.public.windowsxp.general
Andy[_16_]
external usenet poster
 
Posts: 337
Default Turn on computer using power strip

I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."
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  #2  
Old July 21st 18, 05:43 AM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 11,873
Default Turn on computer using power strip

Andy wrote:
I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."


There can be a BIOS power policy setting on desktop
motherboards, which allows booting as soon as the power
is restored. It goes something like this:

"When the power is restored" [Keep computer off] == typical default
[Start computer] == what you want
[Last state] == put computer OFF or ON
depending on whether it
was previously OFF or ON
at the instant the power
dropped (mostly useless
setting).

Some motherboards and their chipset, have actual support.
There won't be any "computer twitching" or "fake starts"
to figure out what power state to use. The computer
instantly responds according to that BIOS setting.

On motherboards where the chipset doesn't really support
the feature, the feature is emulated. On power recovery,
the computer *always* comes on for at least one second.
In that one second, the computer checks the BIOS setting.
It can then decide what to do after that.

On some computers, you get "power on, power off, power on"
as the sequence at startup, as stuff like the above
happens. Some people assume their computer is
busted when it behaves like that, but it's actually
caused by the need to emulate that feature.

Paul
  #3  
Old July 21st 18, 05:44 AM posted to microsoft.public.windowsxp.general
No_Name
external usenet poster
 
Posts: 627
Default Turn on computer using power strip

On Fri, 20 Jul 2018 21:10:33 -0700 (PDT), Andy
wrote:

I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."


The answer is in the BIOS under the Power settings. They usually have
a setting that either powers up every time power is restored or
returns to the state it was in when you shut it off. XP tends to
tolerate dumping power and restarting from pulling the plug better
than W/7. My tiki bar MP3 PC runs this way and it is a little cranky
when I put a 7 machine out there.
  #4  
Old July 21st 18, 07:05 AM posted to microsoft.public.windowsxp.general
No_Name
external usenet poster
 
Posts: 627
Default Turn on computer using power strip

On Sat, 21 Jul 2018 00:43:39 -0400, Paul
wrote:

Andy wrote:
I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."


There can be a BIOS power policy setting on desktop
motherboards, which allows booting as soon as the power
is restored. It goes something like this:

"When the power is restored" [Keep computer off] == typical default
[Start computer] == what you want
[Last state] == put computer OFF or ON
depending on whether it
was previously OFF or ON
at the instant the power
dropped (mostly useless
setting).

Some motherboards and their chipset, have actual support.
There won't be any "computer twitching" or "fake starts"
to figure out what power state to use. The computer
instantly responds according to that BIOS setting.

On motherboards where the chipset doesn't really support
the feature, the feature is emulated. On power recovery,
the computer *always* comes on for at least one second.
In that one second, the computer checks the BIOS setting.
It can then decide what to do after that.

On some computers, you get "power on, power off, power on"
as the sequence at startup, as stuff like the above
happens. Some people assume their computer is
busted when it behaves like that, but it's actually
caused by the need to emulate that feature.

Paul


Back in the early days of ATX supply before the BIOS got smart enough
to start on power restore but it still needed a start signal my hack
was a 5v or 12v relay with the N/C contact connected to the power on
switch (to ground)
When power comes up it sees "power on" and as soon as the supply comes
up the power on shot goes away.
Simply grounding pin 14 might not work.
  #5  
Old July 21st 18, 07:21 AM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 11,873
Default Turn on computer using power strip

wrote:
On Sat, 21 Jul 2018 00:43:39 -0400, Paul
wrote:

Andy wrote:
I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."

There can be a BIOS power policy setting on desktop
motherboards, which allows booting as soon as the power
is restored. It goes something like this:

"When the power is restored" [Keep computer off] == typical default
[Start computer] == what you want
[Last state] == put computer OFF or ON
depending on whether it
was previously OFF or ON
at the instant the power
dropped (mostly useless
setting).

Some motherboards and their chipset, have actual support.
There won't be any "computer twitching" or "fake starts"
to figure out what power state to use. The computer
instantly responds according to that BIOS setting.

On motherboards where the chipset doesn't really support
the feature, the feature is emulated. On power recovery,
the computer *always* comes on for at least one second.
In that one second, the computer checks the BIOS setting.
It can then decide what to do after that.

On some computers, you get "power on, power off, power on"
as the sequence at startup, as stuff like the above
happens. Some people assume their computer is
busted when it behaves like that, but it's actually
caused by the need to emulate that feature.

Paul


Back in the early days of ATX supply before the BIOS got smart enough
to start on power restore but it still needed a start signal my hack
was a 5v or 12v relay with the N/C contact connected to the power on
switch (to ground)
When power comes up it sees "power on" and as soon as the supply comes
up the power on shot goes away.
Simply grounding pin 14 might not work.


Well, grounding pin 14 will work, because it's wired-OR
logic. The motherboard uses open collector drive.
You can't damage the motherboard by shorting pin 14 to
ground. (Not unless a motherboard designer violates
the rules.)

The trick is, to decide when to stop driving pin 14 like
that. I don't know if an OS like Windows 10, puts up
a "it is safe to turn off your computer" like in Win98
days, to indicate it's OK to drop pin 14. You don't want
to drop pin 14, until all caches are flushed.

And you don't need a relay for pin 14 - if you want to
do your own circuit, you can do open collector drive
on your circuit too.

In the old days, for reasons I don't understand, they
used to use powerful open collector drivers. Like a
74F series (74F38?) with 64mA drive. Yet the pullup
resistor on pin 14 isn't supposed to source more than
a couple milliamps. And the other observation is, we
seem to have motherboards where the OC driver fails,
more than it should. So either the notion it's a couple of
milliamps isn't always right, or the designers of
systems 20 years ago were nuts :-) PS_ON# has always
been a bit weird that way. Certainly with your idea of
using a relay, you should always "win". I think modern
designs use less potential drive on PS_ON# than the design
from the old days.

There was some kind of OC driver that I've forgotten the
number now, but it had sufficient drive to drive a
doubly terminated 50 ohm transmission lines. That's how
I buffered clocks on a board with a lot of
discrete clocks. Four of those, one per quadrant.
So in terms of drivers for the PS_ON#, we don't lack
for "gorilla" chips to do the job. The idea of using
8mA drive is so... yesterday. There is a chip
which will drive a 2 amp load, but it's not OC,
so would be inappropriate for the job. I never
got one of those for eval though - would have
been fun to play with. That was a CMOS chip
where the circuit wasn't even considered a logic
gate, more like an amplifier with a gain of 0.9
or so (the output amplitude is slightly smaller
than the input signal).

Paul
  #6  
Old July 21st 18, 02:59 PM posted to microsoft.public.windowsxp.general
No_Name
external usenet poster
 
Posts: 627
Default Turn on computer using power strip

On Sat, 21 Jul 2018 02:21:55 -0400, Paul
wrote:

wrote:
On Sat, 21 Jul 2018 00:43:39 -0400, Paul
wrote:

Andy wrote:
I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."
There can be a BIOS power policy setting on desktop
motherboards, which allows booting as soon as the power
is restored. It goes something like this:

"When the power is restored" [Keep computer off] == typical default
[Start computer] == what you want
[Last state] == put computer OFF or ON
depending on whether it
was previously OFF or ON
at the instant the power
dropped (mostly useless
setting).

Some motherboards and their chipset, have actual support.
There won't be any "computer twitching" or "fake starts"
to figure out what power state to use. The computer
instantly responds according to that BIOS setting.

On motherboards where the chipset doesn't really support
the feature, the feature is emulated. On power recovery,
the computer *always* comes on for at least one second.
In that one second, the computer checks the BIOS setting.
It can then decide what to do after that.

On some computers, you get "power on, power off, power on"
as the sequence at startup, as stuff like the above
happens. Some people assume their computer is
busted when it behaves like that, but it's actually
caused by the need to emulate that feature.

Paul


Back in the early days of ATX supply before the BIOS got smart enough
to start on power restore but it still needed a start signal my hack
was a 5v or 12v relay with the N/C contact connected to the power on
switch (to ground)
When power comes up it sees "power on" and as soon as the supply comes
up the power on shot goes away.
Simply grounding pin 14 might not work.


Well, grounding pin 14 will work, because it's wired-OR
logic. The motherboard uses open collector drive.
You can't damage the motherboard by shorting pin 14 to
ground. (Not unless a motherboard designer violates
the rules.)

The trick is, to decide when to stop driving pin 14 like
that. I don't know if an OS like Windows 10, puts up
a "it is safe to turn off your computer" like in Win98
days, to indicate it's OK to drop pin 14. You don't want
to drop pin 14, until all caches are flushed.

And you don't need a relay for pin 14 - if you want to
do your own circuit, you can do open collector drive
on your circuit too.

In the old days, for reasons I don't understand, they
used to use powerful open collector drivers. Like a
74F series (74F38?) with 64mA drive. Yet the pullup
resistor on pin 14 isn't supposed to source more than
a couple milliamps. And the other observation is, we
seem to have motherboards where the OC driver fails,
more than it should. So either the notion it's a couple of
milliamps isn't always right, or the designers of
systems 20 years ago were nuts :-) PS_ON# has always
been a bit weird that way. Certainly with your idea of
using a relay, you should always "win". I think modern
designs use less potential drive on PS_ON# than the design
from the old days.

There was some kind of OC driver that I've forgotten the
number now, but it had sufficient drive to drive a
doubly terminated 50 ohm transmission lines. That's how
I buffered clocks on a board with a lot of
discrete clocks. Four of those, one per quadrant.
So in terms of drivers for the PS_ON#, we don't lack
for "gorilla" chips to do the job. The idea of using
8mA drive is so... yesterday. There is a chip
which will drive a 2 amp load, but it's not OC,
so would be inappropriate for the job. I never
got one of those for eval though - would have
been fun to play with. That was a CMOS chip
where the circuit wasn't even considered a logic
gate, more like an amplifier with a gain of 0.9
or so (the output amplitude is slightly smaller
than the input signal).

Paul


For some reason the machine I was working on would not run if I just
jumpered pin 14. It powered up but it did not work. I suspect the BIOS
really wants to see the power button pressed and released. The relay
on the power button circuit fixed that.
  #7  
Old July 21st 18, 05:04 PM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 11,873
Default Turn on computer using power strip

wrote:
On Sat, 21 Jul 2018 02:21:55 -0400, Paul
wrote:

wrote:
On Sat, 21 Jul 2018 00:43:39 -0400, Paul
wrote:

Andy wrote:
I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."
There can be a BIOS power policy setting on desktop
motherboards, which allows booting as soon as the power
is restored. It goes something like this:

"When the power is restored" [Keep computer off] == typical default
[Start computer] == what you want
[Last state] == put computer OFF or ON
depending on whether it
was previously OFF or ON
at the instant the power
dropped (mostly useless
setting).

Some motherboards and their chipset, have actual support.
There won't be any "computer twitching" or "fake starts"
to figure out what power state to use. The computer
instantly responds according to that BIOS setting.

On motherboards where the chipset doesn't really support
the feature, the feature is emulated. On power recovery,
the computer *always* comes on for at least one second.
In that one second, the computer checks the BIOS setting.
It can then decide what to do after that.

On some computers, you get "power on, power off, power on"
as the sequence at startup, as stuff like the above
happens. Some people assume their computer is
busted when it behaves like that, but it's actually
caused by the need to emulate that feature.

Paul
Back in the early days of ATX supply before the BIOS got smart enough
to start on power restore but it still needed a start signal my hack
was a 5v or 12v relay with the N/C contact connected to the power on
switch (to ground)
When power comes up it sees "power on" and as soon as the supply comes
up the power on shot goes away.
Simply grounding pin 14 might not work.

Well, grounding pin 14 will work, because it's wired-OR
logic. The motherboard uses open collector drive.
You can't damage the motherboard by shorting pin 14 to
ground. (Not unless a motherboard designer violates
the rules.)

The trick is, to decide when to stop driving pin 14 like
that. I don't know if an OS like Windows 10, puts up
a "it is safe to turn off your computer" like in Win98
days, to indicate it's OK to drop pin 14. You don't want
to drop pin 14, until all caches are flushed.

And you don't need a relay for pin 14 - if you want to
do your own circuit, you can do open collector drive
on your circuit too.

In the old days, for reasons I don't understand, they
used to use powerful open collector drivers. Like a
74F series (74F38?) with 64mA drive. Yet the pullup
resistor on pin 14 isn't supposed to source more than
a couple milliamps. And the other observation is, we
seem to have motherboards where the OC driver fails,
more than it should. So either the notion it's a couple of
milliamps isn't always right, or the designers of
systems 20 years ago were nuts :-) PS_ON# has always
been a bit weird that way. Certainly with your idea of
using a relay, you should always "win". I think modern
designs use less potential drive on PS_ON# than the design
from the old days.
There was some kind of OC driver that I've forgotten the
number now, but it had sufficient drive to drive a
doubly terminated 50 ohm transmission lines. That's how
I buffered clocks on a board with a lot of
discrete clocks. Four of those, one per quadrant.
So in terms of drivers for the PS_ON#, we don't lack
for "gorilla" chips to do the job. The idea of using
8mA drive is so... yesterday. There is a chip
which will drive a 2 amp load, but it's not OC,
so would be inappropriate for the job. I never
got one of those for eval though - would have
been fun to play with. That was a CMOS chip
where the circuit wasn't even considered a logic
gate, more like an amplifier with a gain of 0.9
or so (the output amplitude is slightly smaller
than the input signal).

Paul


For some reason the machine I was working on would not run if I just
jumpered pin 14. It powered up but it did not work. I suspect the BIOS
really wants to see the power button pressed and released. The relay
on the power button circuit fixed that.


Ah, OK, different animal :-)

The mobo conditioning logic is part of the supervisory
circuitry on the motherboard. And the +5VSB comes
from the supervisory part of the ATX PSU.

+5VSB
| X PS_ON# --- 1K pullup to +5VSB
| / Pin 14
Power X----------- Mobo --------------|
button conditioning \ ATX PSU
(momentary, logic GND
normally open) --- Power_Good

___ ___ ______
|__| |___
rising-edge sensitive. output is a level
also it is time-filtered
^
+---- You are using your relay here...

The mobo conditioning logic is either in
the Southbridge (PCH) or SuperI/O. These
days, there aren't a lot of other chips left...

The mobo conditioning logic converts a pulse
into a level on PS_ON#. The conditioning logic
is also writeable by the processor. The timing
filter on the button press is short at first.
(It's easy to turn off the PC when in the BIOS.)

But, if the OS is running, the power button
has a four second "filter" on it, such that
you have to press and hold the front button,
to get whatever function is bound to the
power button, to start doing its thing.
Normally, the ACPI power button would be
bound to "shutdown", as an example. It could
also be tied to "sleep" if you wanted.

The front button does not have "direct effect".
It's a [partially] software mediated button.
The switch on the back of the PSU, is a
direct effect switch that cuts the mains.

What comes over to pin 14 is a "level". The PSU
remain ON for as long as PS_ON# is grounded.
Driving at the pin 14 point is Open Collector,
and works like a light switch (level sensitive
not edge sensitive). That's what I was addressing
in the other post, is driving pin 14. There
is no continuity between pin 14 and the front
momentary contact switch.

The open collector driver sinks the few milliamps
that the pullup provides on pin 14.

The power supply doesn't have to use an actual
logic gate on Pin 14. But it's pretty easy today
for a chip to be inside the PSU, listening for
a standard logic signal. That's because the
regulator chip in the PSU is probably an LSI
with a fair number of pins on it.

In the schematic here, PS_ON# is on the left edge of
the schematic. There's a 4.7K resistor to +5VSB
and there would be 1 milliamp sunk to ground on
the motherboard end of PS_ON# pin 14.

http://www.pavouk.org/hw/en_atxps.html

Paul
  #8  
Old July 21st 18, 05:36 PM posted to microsoft.public.windowsxp.general
Andy[_16_]
external usenet poster
 
Posts: 337
Default Turn on computer using power strip

On Friday, July 20, 2018 at 11:43:42 PM UTC-5, Paul wrote:
Andy wrote:
I have my computer plugged in to a power strip.

Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

Thanks,
Andy

"It's always too early to quit."


There can be a BIOS power policy setting on desktop
motherboards, which allows booting as soon as the power
is restored. It goes something like this:

"When the power is restored" [Keep computer off] == typical default
[Start computer] == what you want
[Last state] == put computer OFF or ON
depending on whether it
was previously OFF or ON
at the instant the power
dropped (mostly useless
setting).

Some motherboards and their chipset, have actual support.
There won't be any "computer twitching" or "fake starts"
to figure out what power state to use. The computer
instantly responds according to that BIOS setting.

On motherboards where the chipset doesn't really support
the feature, the feature is emulated. On power recovery,
the computer *always* comes on for at least one second.
In that one second, the computer checks the BIOS setting.
It can then decide what to do after that.

On some computers, you get "power on, power off, power on"
as the sequence at startup, as stuff like the above
happens. Some people assume their computer is
busted when it behaves like that, but it's actually
caused by the need to emulate that feature.

Paul


I set it to always on.

But it doesn't work.

I realized my computer is plugged into an APC.

So in effect, it always has power to it.

If I turned the APC on and off, I would have to listening to it's beeping.


Andy
  #9  
Old July 21st 18, 05:51 PM posted to microsoft.public.windowsxp.general
J. P. Gilliver (John)[_4_]
external usenet poster
 
Posts: 2,679
Default Turn on computer using power strip

In message , Paul
writes:
[]
The front button does not have "direct effect".
It's a [partially] software mediated button.
The switch on the back of the PSU, is a
direct effect switch that cuts the mains.


If it's there; not all power supplies _have_ the back panel rocker
switch. (Or have regulations changed and they have to nowadays?)
[]
the schematic. There's a 4.7K resistor to +5VSB
and there would be 1 milliamp sunk to ground on
the motherboard end of PS_ON# pin 14.

[]
Or slightly over 1 mA, of course. Isn't it funny that resistors (and
capacitors, and many inductors) are still made to the E12 series, which
dates from when they were sorted into bins as they came out of the
machine that made them, whereas they're usually precision-made to 2% or
even 1% these days!
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

aibohphobia, n., The fear of palindromes.
  #10  
Old July 22nd 18, 01:48 AM posted to microsoft.public.windowsxp.general
Ant[_2_]
external usenet poster
 
Posts: 554
Default Turn on computer using power strip

Someone told me it was a bad idea to everything on from a power strip.
Is this true?


Andy wrote:
I have my computer plugged in to a power strip.


Is there a way to turn on my computer just by powering on the power strip instead of having to hit power button on computer?

....
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  #12  
Old July 22nd 18, 06:23 AM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 11,873
Default Turn on computer using power strip

J. P. Gilliver (John) wrote:
In message , Paul
writes:
[]
The front button does not have "direct effect".
It's a [partially] software mediated button.
The switch on the back of the PSU, is a
direct effect switch that cuts the mains.


If it's there; not all power supplies _have_ the back panel rocker
switch. (Or have regulations changed and they have to nowadays?)
[]
the schematic. There's a 4.7K resistor to +5VSB
and there would be 1 milliamp sunk to ground on
the motherboard end of PS_ON# pin 14.

[]
Or slightly over 1 mA, of course. Isn't it funny that resistors (and
capacitors, and many inductors) are still made to the E12 series, which
dates from when they were sorted into bins as they came out of the
machine that made them, whereas they're usually precision-made to 2% or
even 1% these days!


It's a pullup resistor. Just an order of magnitude of
current flow is required in a discussion of such. You
could use a 4.7K 5% or a 5.1K 5% and nobody would know
the difference.

I'm feeling nostalgic now, for my TI Bible...

It probably had the equations spelled out for working
out what pullup to use :-) [It would involve a discussion
about wired-OR logic using open collector drive, N outputs
wired to M inputs, and what pullup resistor is required.]
In this case N=1 and M = approximately 1.

https://cdn.eeweb.com/articles/artic...web-dsl-01.jpg

And switching a 1mA current flow with a relay, may not
provide enough current to keep the relay contacts clean.
Relays have a maximum current, but they also have a
minimum current flow they can handle if you expect
the contacts to remain clean and trouble-free. Even
with a precious metal coating there will still be
a minimum current flow spec. I might go looking for
a reed relay to do it perhaps. Rather than the
contactor off an air conditioner. Contact bounce ?
Not a problem driving the front panel Power button.
Might need to think about the consequences of
driving pin 14 with such. This is why semiconductor
drive is "nicer". And in this case, you could use
an optoisolator to close the contacts if you wanted.

Paul
  #13  
Old July 22nd 18, 06:44 AM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 11,873
Default Turn on computer using power strip

Ant wrote:
Someone told me it was a bad idea to everything on from a power strip.
Is this true?


Andy wrote:
I have my computer plugged in to a power strip.


Is there a way to turn on my computer just by powering
on the power strip instead of having to hit power button on computer?


Take the "average" electrical device for a moment.

Plugging the device into the wall, applies mains to it instantly.

Flipping the switch on the power strip, applies mains to it instantly.

There is no difference from that perspective.

A switching power supply needs an inrush limiter in any
case, to help limit the flow of mains current at T=0.
Without some sort of limitation, the bridge rectifier
could blow out. On a typical ATX supply, this number
can actually amount to 40 amps or 80 amps for the first
cycle. A secondary effect of connecting certain
ATX supplies, is it "makes your UPS beep", as the
inrush is so large, the UPS mis-interprets the load
as an "overload" condition. (It's the combination of
current flow level and the time the overload is present,
that determines whether the UPS will beep. Hitting 80 amps
for a microsecond, hurts nothing.)

I have one ATX supply here, my Sparkle supply, which causes
the UPS to beep no matter how the Sparkle gets connected to mains.

*******

If switching a power strip with nothing but wall warts,
there is little to worry about.

However, if a PC is on the power strip, wait
30 seconds for +5VSB to drain. This allows the motherboard
to enter an "uninitialized" state electrically, so that the
next startup is nice and clean, and all the logic starts
from an "unpowered" state.

The other time constant involved, is the time for the
inrush limiter NTC resistor to cool off. It normally
runs hot, and in the hot state, has low resistance.
In the cold state, it has high resistance. If you
wait 60 seconds after flipping the power strip off,
the NTC cools off, the resistance is high, and the
charging current into the main cap uses a lower
current flow value as a result. The UPS is less likely
to beep. Once the NTC resistor heats up, the resistance
drops, and the NTC resistor becomes "more efficient"
for running during the rest of the session. To make
the NTC run hot, wastes a tiny bit of electricity
during normal operation.

Summary: Wait 60 seconds after power strip "flip off",
before your next "flip on". *Do not* toggle
the living daylights out of it. Try not to
make a stroboscope using your power strip
switch. It can actually cause an ATX power
supply to "blow" if you do that. A poster in
one of the hardware groups managed to do that :-)
That's how we know "what the consequence of
being an idiot" are :-)

If you treat the switch with some respect, there
is no reason to fear it.

Paul
  #14  
Old July 22nd 18, 10:23 AM posted to microsoft.public.windowsxp.general
R.Wieser
external usenet poster
 
Posts: 1,302
Default Turn on computer using power strip

Ant,

Someone told me it was a bad idea to everything on from a
power strip. Is this true?


(the below is an answer to the above, switching ON. Swiching off by it has
got its own, and already described, problems)

It depends. On what ? On how your computers power supplies respond to
it.

In the old days there was little done about the so-called "inrush" current
(the current a power supply could draw in the first few mSec its turned on -
which can be a number of times its normal one), and as such a few of such
power supplies together could reasily excess a classic fuses maximum spike
current, and blow out.

Nowerdays with all those (slow!) automatic fuses and (computer) power
supplies that are protected agains the effects of inrush current its not as
much as a problem anymore.

In my case I've got at least four PCs and a laser printer on the same power
strip (as well as several power warts, some feeding routers) which I'm using
every day (on in the morning, off in the evening), and have never had a
problem with it.

Regards,
Rudy Wieser




"Ant" wrote in message
...
Someone told me it was a bad idea to everything on from a power strip.
Is this true?


Andy wrote:
I have my computer plugged in to a power strip.


Is there a way to turn on my computer just by powering on the power strip
instead of having to hit power button on computer?

...
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tail." --Armenian and Maltese
Note: A fixed width font (Courier, Monospace, etc.) is required to see
this signature correctly.
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  #15  
Old July 22nd 18, 10:40 AM posted to microsoft.public.windowsxp.general
Paul[_32_]
external usenet poster
 
Posts: 11,873
Default Turn on computer using power strip

R.Wieser wrote:
Ant,

Someone told me it was a bad idea to everything on from a
power strip. Is this true?


(the below is an answer to the above, switching ON. Swiching off by it has
got its own, and already described, problems)

It depends. On what ? On how your computers power supplies respond to
it.

In the old days there was little done about the so-called "inrush" current
(the current a power supply could draw in the first few mSec its turned on -
which can be a number of times its normal one), and as such a few of such
power supplies together could reasily excess a classic fuses maximum spike
current, and blow out.

Nowerdays with all those (slow!) automatic fuses and (computer) power
supplies that are protected agains the effects of inrush current its not as
much as a problem anymore.

In my case I've got at least four PCs and a laser printer on the same power
strip (as well as several power warts, some feeding routers) which I'm using
every day (on in the morning, off in the evening), and have never had a
problem with it.

Regards,
Rudy Wieser


There are two ways to handle inrush.

NTC thermistor is the old way. Runs hot under normal operation,
starts out "cold" to work properly at the application of mains power.

The new way, is a side effect of the Active PFC controller. It's possible
as the power supply starts, to use the active PFC controller in a
series pass mode, for the purposes of limiting inrush. After a
suitable (short) interval, it becomes line interactive as it
attempts to make the voltage and current waveforms "in sync",
dropping the power factor to unity. (Older power supplies
have a power factor of 0.65, and current is not in phase
with voltage. In addition, the current waveform isn't
a sinusoid any more either and has a harmonic content.)

Someone mentioned power supplies with no switch on them.
My old Mac G4 works that way. It has no switch. After a short
delay after plugin, you hear a relay engage. Presumably the
interval between the two events, allows for a "slow charging"
of the main capacitor. So that, not even the relay gets
ripped to shreds by the inrush.

We had an inrush problem with a product at work, and the
responsible manager placed a *40amp* relay between the
mains and the (poorly designed third party) PSU. The 40amp
rating would be sufficient to "take inrush forever", and
there were never any reports of trouble with the relay
based design. It also made a satisfying "clunk" noise
at startup.

There was a rather large retail power supply reviewed at
Anandtech in the last year, and (apparently) the company
that designed it "forgot" to put any kind of inrush
solution in it. Anandtech reported that the breaker
in their breaker panel tripped, each time the supply
was powered up. Now, I want one of those, because I
haven't really tested the breakers in my panel for
some time.

Paul
 




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