prolong the life of electronics and bearings

[Paul]

I leave pc power on usually 24/7, rebooting about once a week. Is it better
for the electronics to stay on 24/7?

If I leave a room for under one hour I leave the light bulb on, because I
think they last longer. The "power on" surge really stresses the filament.

If I stop watching TV, but will be watching again in under 5 hours, I leave
it on. I think this prolongs the life.

If I stop my car somewhere, but will be using it again in under 5 minutes, I
leave it on.

Yes, I do realize that a car engine is not in the same category.

Back to the PC. If it will not be used for over about 5 hours, I will put it
in standby, which turns off the monitor and spins down the HDD. However, I
think that I should spin down the HDD if I will not be used for as little as
one hour.

Yes, all these times are arbitrary. They just feel about right to me.
Although, I sometimes think that I should power down the pc if I will not be
using it for over 8 hours, but I don't.

Comments? (that is besides that I have too much time on my hands to be
worried about all this)

Paul

 

[David Candy]

Some things wear on cycles (tyres on an aircraft landing) and other on time operating (aircraft engines).

 

[Guest]

you are somewhat correct. Very few light bulbs burn out, if they are
already ON, they burn out when being turned on, not because of Stress but
because of a Voltage Surge. It is better for some of the circuit to be left
on and standby is better than just ON, that way the voltage is regulated and
not surging at every turn on and yet parts are not cooking or burning from
prolong useage. Energy consumption is the other part of the coin, you are
still consuming power, regardless and power is energy and that has to come
from somewhere.
As far as your car is concerned, you are correct there as well. It is
better to buy a Used car that is only a couple of years old and lotsa mileage
versus an older car with little mileage. Reason is simple. Most cars have
their Oil pans below the engines (except U.S. Military) and when the car is
turned off, oil returns to the oil pan thru a force called Gravity. When you
crank the car, you are rubbing metal against bare metal until the lubricant
arrives, in so doing, you wear the engine more in starting it than allowing
it to run for several hours or driving for hundreds of miles. This is one of
the reasons, other than Deeisels have less moving parts, that Tractor Trailer
Trucks can go hundreds of thousands of miles without major repairs. They
usually drive 4000 plus miles per week.
Use a good oil and change filters regularly and you will add life as well.
Not much to do with Windows XP but good info just the same.

 

[Eddy]

.... Very few light bulbs burn out, if they are
already ON, they burn out when being turned on, not because of Stress but
because of a Voltage Surge.
....

Not quite correct.

It is a "current surge", not a "voltage surge".
A cold filament has a lower resistance than a hot filament, so at switch on
the current is higher until the filament gets up to normal working
temperature. Assuming a normal mains supply, the voltage across the bulb
does not change.

 

[Davy]

Craig A.wrote
quote="Craig A."]you are somewhat correct. Very few light bulb
burn out, if they are already ON, you are somewhat correct. Ver
few light bulbs burn out, if they are already ON
[/quote:97233e8ca0

I'll agree with Craig here, TV's etc contain a power supply usuall
being of the switch-mode type, now then just briefly, the main
input power is rectified from ac into a dc voltage so we'll say it
connected to a 220V ac outlet, after rectfication you'll end up wit
220 x 1.4, 308 volt dc across the main smoothing capacitor tha
filters the ripples to produce a steady DC supply this is fed to th
'chopper' transistor or chip

When the set is first switched 'on', or after it's been 'off' fo
about ten minutes or so, that capacitor is discharged, as soon as th
set is switched on, the capacitor represents a short circuit acros
the rectifiers and the mains for a few milli-seconds untill it begin
to charge, this causes a surge as Craig mentions and a large amount
current flows for a few milli seconds, you have a larger amount o
current flow around an ampere or so in the degausing
(de-magentising) coils around the CRT screens in TV's and compute
monitors for a few seconds

Leaving a TV or monitor on can be a good thing, it can also be a ba
thing.

Even leaving it on in stand-by, the 308 volts from the smoothin
capacitor is then 'chopped' or switched on and off at about 18,00
times a second or 18Khz, this creates large voltage excursions on th
drive waveform, any badly soldered joints could easily arc generatin
enough heat to actually cause the PCB to burn, which indeed coul
have very serious consequences should anything ignite

I have had three Philips Modern TV's with faulty power switches, On
of them melted a hole in the cabinet.... and for safety reasons th
TV had to be scrapped, the people was very, very lucky it was onl
the cabinet - it could have set the entire house on fire.

Now then think about it...
The TV is turned off, nice and cool isn't it..? turn it on for a fe
hours things get warm, you' might then turn it off for the day, i
goes cool again....

Solder is soft, what happens after a long period of this 'hea
cycling' the solder around the connections cracks, we call it in th
trade a "dry joint", which could create arc and sparks as mentioned
solder being about 60% lead and 40% tin is very soft - so leaving
set on one would imagine would prevent this problem, these dry joint
can happen at any time even on brand new equipment

Also you may get voltage surges on the mains outlet, voltages tha
could rise several 1000s of volts for a split second, caused by win
blowing the power lines, thunderstorms etc. the could blow th
switch- mode power supplies or cause chips to be damaged even if lef
in standby

Note these voltage spikes and surges can not be measured with th
normal test meter because the rise time is far far too fast for the
to register but are easily seen on an oscilloscope

So I would say always err on the safe side, if not in use for lon
periods it really is better to turn the things like this off and no
leave them on in stand-b

Dav

 

[Davy]

Davywrote
[quote:2d444613b1]quote="Craig A."]you are somewhat correct. Ver
few light bulbs burn out, if they are already ON, quote="Crai
A."]you are somewhat correct. Very few light bulbs burn out, i
they are already ON, [/quote:2d444613b1

I'll agree with Craig here, TV's etc contain a power supply usuall
being of the switch-mode type, now then just briefly, the main
input power is rectified from ac into a dc voltage so we'll say it
connected to a 220V ac outlet, after rectfication you'll end up wit
220 x 1.4, 308 volt dc across the main smoothing capacitor tha
filters the ripples to produce a steady DC supply this is fed to th
'chopper' transistor or chip

When the set is first switched 'on', or after it's been 'off' fo
about ten minutes or so, that capacitor is discharged, as soon as th
set is switched on, the capacitor represents a short circuit acros
the rectifiers and the mains for a few milli-seconds untill it begin
to charge, this causes a surge as Craig mentions and a large amount
current flows for a few milli seconds, you have a larger amount o
current flow around an ampere or so in the degausing
(de-magentising) coils around the CRT screens in TV's and compute
monitors for a few seconds

Leaving a TV or monitor on can be a good thing, it can also be a ba
thing.

Even leaving it on in stand-by, the 308 volts from the smoothin
capacitor is then 'chopped' or switched on and off at about 18,00
times a second or 18Khz, this creates large voltage excursions on th
drive waveform, any badly soldered joints could easily arc generatin
enough heat to actually cause the PCB to burn, which indeed coul
have very serious consequences should anything ignite

I have had three Philips Modern TV's with faulty power switches, on
of them melted a hole in the cabinet.... and for safety reasons th
TV had to be scrapped, the people was very, very lucky it was onl
the cabinet - it could have set the entire house on fire.

Now then think about it...
The TV is turned off, nice and cool isn't it..? turn it on for a fe
hours things get warm, you' might then turn it off for the day, i
goes cool again....

Solder is soft, what happens after a long period of this 'hea
cycling' the solder around the connections cracks, we call it in th
trade a "dry joint", which could create arc and sparks as mentioned
solder being about 60% lead and 40% tin is very soft - so leaving
set on one would imagine would prevent this problem, these dry joint
can happen at any time even on brand new equipment

Also you may get voltage surges on the mains outlet, voltages tha
could rise several 1000s of volts for a split second, caused by win
blowing the power lines, thunderstorms etc. these could blow th
switch-mode power supplies or cause chips to be damaged even if lef
in standby

Note these voltage spikes and surges can not be measured with th
normal test meter because the rise time is far far too fast for the
to register but are easily seen on an oscilloscope

So I would say always err on the safe side, if not in use for lon
periods it really is better to turn the things like this off and no
leave them on in stand-by for long period

Dav

 

[Guest]

The Voltage will indeed Surge, but you are right it IS the Current (amps)
that will cause the problem. I used a Bulb as reference, but even if a Water
Pump kicks on or a Refrigator Compressor, the Amps will surge almost 20%.
What you said about the filament is basically true with any Resistant Load
Device, or in simple terms Heating Element which a Carbon filament is. As fas
as Inductive Load type devices it is not the case but surges still occur.
Voltage surging is the reason why you should always hook up a portable
device that is voltage sensitive to a regulated Power Supply, hence why a
Laptop DC Adapter is $60 versus $2.99. Or an AC Regulated Power Supply versus
a Non-regulated. Voltage Spikes are common and most appliances are capable of
handling a plus or minus 10% variance. With motors the rpms will vary unless
they are Servos or controlled with a Capacitor. This also happens at the
time of turning on the device.

 

[David Candy]

Off appliances don't catch fire either.

--
--------------------------------------------------------------------------------------------------
Read David defending the concept of violence.
http://margokingston.typepad.com/harry_version_2/2005/10/entering_the_ga.html#more
=================================================

Craig A.wrote:

quote="Craig A."]you are somewhat correct. Very few light bulbs
burn out, if they are already ON, you are somewhat correct. Very
few light bulbs burn out, if they are already ON,
[/quote:97233e8ca0]

I'll agree with Craig here, TV's etc contain a power supply usually
being of the switch-mode type, now then just briefly, the mains
input power is rectified from ac into a dc voltage so we'll say its
connected to a 220V ac outlet, after rectfication you'll end up with
220 x 1.4, 308 volt dc across the main smoothing capacitor that
filters the ripples to produce a steady DC supply this is fed to the
'chopper' transistor or chip.

When the set is first switched 'on', or after it's been 'off' for
about ten minutes or so, that capacitor is discharged, as soon as the
set is switched on, the capacitor represents a short circuit across
the rectifiers and the mains for a few milli-seconds untill it begins
to charge, this causes a surge as Craig mentions and a large amount a
current flows for a few milli seconds, you have a larger amount of
current flow around an ampere or so in the degausing
(de-magentising) coils around the CRT screens in TV's and computer
monitors for a few seconds.

Leaving a TV or monitor on can be a good thing, it can also be a bad
thing.

Even leaving it on in stand-by, the 308 volts from the smoothing
capacitor is then 'chopped' or switched on and off at about 18,000
times a second or 18Khz, this creates large voltage excursions on the
drive waveform, any badly soldered joints could easily arc generating
enough heat to actually cause the PCB to burn, which indeed could
have very serious consequences should anything ignite.

I have had three Philips Modern TV's with faulty power switches, One
of them melted a hole in the cabinet.... and for safety reasons the
TV had to be scrapped, the people was very, very lucky it was only
the cabinet - it could have set the entire house on fire..

Now then think about it...?
The TV is turned off, nice and cool isn't it..? turn it on for a few
hours things get warm, you' might then turn it off for the day, it
goes cool again....!

Solder is soft, what happens after a long period of this 'heat
cycling' the solder around the connections cracks, we call it in the
trade a "dry joint", which could create arc and sparks as mentioned,
solder being about 60% lead and 40% tin is very soft - so leaving a
set on one would imagine would prevent this problem, these dry joints
can happen at any time even on brand new equipment.

Also you may get voltage surges on the mains outlet, voltages that
could rise several 1000s of volts for a split second, caused by wind
blowing the power lines, thunderstorms etc. the could blow the
switch- mode power supplies or cause chips to be damaged even if left
in standby.

Note these voltage spikes and surges can not be measured with the
normal test meter because the rise time is far far too fast for them
to register but are easily seen on an oscilloscope.

So I would say always err on the safe side, if not in use for long
periods it really is better to turn the things like this off and not
leave them on in stand-by

Davy

 

[bumtracks]

big bulbs sometimes burn out when turned off
its the off surge,,,, like water hammer.

 

[w_tom]

Power cycling does cause stress. That is the Rush Limbaugh
response. Then we consult numbers. Stress is so trivial as
to be virtually zero.

Take light bulbs as an example. Power cycling does not
adversely affect light bulbs. For if it did, then amber
lights in traffic signals (flashing all night long) would be
replaced constantly. So instead we first consult industry
specs such as from the IES Handbook. Light bulb life
expectancy is determined by hours of operation and by voltage
- as even an amber traffic signal demonstrates. Major stress
during power-on is speculation. Notice when the light bulb
fails - while on or during power on - first a dark spot forms
inside the bulb. That is vaporized filament damaged as
defined by above numbers - hours of operation and line
voltage.

Look at a computer. When is some of the most stressful
power cycling? When the computer is on. In fact, one of the
most stressful events is hundreds of amps per microsecond.
Switching is so stressful that transistors literally emit IR
radiation only during the switching event. This most
stressful event occurs in normal CPU operation. What is most
every transistor doing inside that CPU? Switching on and off
repeatedly. What do manufacturer spec sheets cite for life
expectancy? Not power cycling. Data sheets cite 'hours of
operation'.

So if I sleep the machine, then it will not suffer power-on
stress? What do you think that sleep function is? Remove
power from most of the machine. Those parts suffer same power
up whether in full powerup or if powered from sleep. Just
another in a long list of reasons why power off is not
destructive.

Another cites a discharged capacitor being fully charged on
powerup. Well, first, one should first learn about everything
in that power supply. Even in 1950s televisions, power up was
restricted by the inrush current limiter. IOW that sudden
charge to a capacitor does not happen on power up when one
first learns of functions inside power supplies - even 1950s
power supplies.

Best thing one can do is power down or hibernate the PC when
done. This based upon numbers from data sheets - not based
upon speculation from personal observations. To extend
incandescent light bulb life expectancy, turn it off when
leaving the room. These based upon facts from their respected
industry. Observations not tempered by knowledge of how it
works simply create urban myths.

Power cycling a disk drive is destructive. We even cite a
manufacturer's number. Lowest number I ever saw was a drive
rated for 40,000 power cycles. That is seven power cycles
every day for..... 15+ years. Who cares? And who power
cycles seven days every day? Notice how numbers make
subjective speculation totally irrelevant.

Destructive power cycling becomes myth once we apply the
numbers. Who forgot to mention that standard component -
inrush current limiter? And why?

Up top, Rush Limbaugh reasoning was defined. Hype
subjective claims into irrefutable facts - if the audience is
gullible. Notice how something become 180 degrees different
once we apply the numbers. Using numbers, power cycling of a
TV, a computer, an incandescent bulb, etc are not
destructive. Unfortunately too many use Rush Limbaugh logic -
avoid numbers - assume that power cycling is destructive.
Most power cycling occurs when digital electronics operate.
Which is why life expectancy is often defined in hours of
operation. Those damning numbers. Did your observations
forget to notice why the 'flashing all night' amber traffic
light fails least often? Hours of operation - not power
cycling - is destructive. Turn it off or hibernate it when
done - to increase life expectancy.

 

[Paul]

You had to know that I would ask: How long is: "long
periods"

P

Craig A.wrote:

quote="Craig A."]you are somewhat correct. Very few light bulbs
burn out, if they are already ON, you are somewhat correct. Very
few light bulbs burn out, if they are already ON,
[/quote:97233e8ca0]

I'll agree with Craig here, TV's etc contain a power supply usually
being of the switch-mode type, now then just briefly, the mains
input power is rectified from ac into a dc voltage so we'll say its
connected to a 220V ac outlet, after rectfication you'll end up with
220 x 1.4, 308 volt dc across the main smoothing capacitor that
filters the ripples to produce a steady DC supply this is fed to the
'chopper' transistor or chip.

When the set is first switched 'on', or after it's been 'off' for
about ten minutes or so, that capacitor is discharged, as soon as the
set is switched on, the capacitor represents a short circuit across
the rectifiers and the mains for a few milli-seconds untill it begins
to charge, this causes a surge as Craig mentions and a large amount a
current flows for a few milli seconds, you have a larger amount of
current flow around an ampere or so in the degausing
(de-magentising) coils around the CRT screens in TV's and computer
monitors for a few seconds.

Leaving a TV or monitor on can be a good thing, it can also be a bad
thing.

Even leaving it on in stand-by, the 308 volts from the smoothing
capacitor is then 'chopped' or switched on and off at about 18,000
times a second or 18Khz, this creates large voltage excursions on the
drive waveform, any badly soldered joints could easily arc generating
enough heat to actually cause the PCB to burn, which indeed could
have very serious consequences should anything ignite.

I have had three Philips Modern TV's with faulty power switches, One
of them melted a hole in the cabinet.... and for safety reasons the
TV had to be scrapped, the people was very, very lucky it was only
the cabinet - it could have set the entire house on fire..

Now then think about it...?
The TV is turned off, nice and cool isn't it..? turn it on for a few
hours things get warm, you' might then turn it off for the day, it
goes cool again....!

Solder is soft, what happens after a long period of this 'heat
cycling' the solder around the connections cracks, we call it in the
trade a "dry joint", which could create arc and sparks as mentioned,
solder being about 60% lead and 40% tin is very soft - so leaving a
set on one would imagine would prevent this problem, these dry joints
can happen at any time even on brand new equipment.

Also you may get voltage surges on the mains outlet, voltages that
could rise several 1000s of volts for a split second, caused by wind
blowing the power lines, thunderstorms etc. the could blow the
switch- mode power supplies or cause chips to be damaged even if left
in standby.

Note these voltage spikes and surges can not be measured with the
normal test meter because the rise time is far far too fast for them
to register but are easily seen on an oscilloscope.

So I would say always err on the safe side, if not in use for long
periods it really is better to turn the things like this off and not
leave them on in stand-by

Davy

 

[Borg hater]

Am under a different philosophy, conservation of energy over your premise
regarding electric/electronic/mechanical device life. If you aren't using
it, turn it off.

If I get out of the car for any reason, I turn the engine off and remove the
keys, and place the keys in my pocket. If I see no end to traffic at a
complete standstill, I turn the engine off. It doesn't take 5 minutes to
make that decision for me. Some never turn their engines off if stuck in
traffic at a dead stop, no matter how long the delay. Gasp, no AC! Then
there's the convenience store stop, but leave the engine running with a 4
year old behind the wheel and a toddler getting his face licked by the
family dog. Nevermind potential theft, with or without the kids in the car.
All of these folks are braindead folks in my opinion. This portion is not
related to XP in any shape, fashion, or form. Hope the Borg forgive us.

 

[David Candy]

Ignore this guy as he posts the rant and is wrong.

 

[Leythos]

Ignore this guy as he posts the rant and is wrong.

I thought everyone already knew that anything spouted by w_tom was
mostly BS anyway.

 

[David Candy]

He is 1/2 right but becomes wrong once he applies it to everything.

 

[Leythos]

He is 1/2 right but becomes wrong once he applies it to everything.

I can agree with that.

 

[Rctfreak]

If I get out of the car for any reason, I turn the engine off and remove the
keys, and place the keys in my pocket. If I see no end to traffic at a
complete standstill, I turn the engine off. It doesn't take 5 minutes to
make that decision for me. Some never turn their engines off if stuck in
traffic at a dead stop, no matter how long the delay. Gasp, no AC! Then
there's the convenience store stop, but leave the engine running with a 4
year old behind the wheel and a toddler getting his face licked by the
family dog. Nevermind potential theft, with or without the kids in the car.
All of these folks are braindead folks in my opinion. This portion is not
related to XP in any shape, fashion, or form. Hope the Borg forgive us.

Where I live, the people who run into the convenience store and leave
their car running not only face the potential of someone jumping in
and stealing it, they also face the potential of a ticket from the
local police. Leaving a car running while unattended is against the
law here.

I am like you. Doesn't matter how long I am going to be out of the
car, the car is shut off and the keys go in my pocket after I lock the
car.

 

[Plato]

I leave pc power on usually 24/7, rebooting about once a week. Is it better
for the electronics to stay on 24/7?

For the pc it doesn't matter. If you have a CRT monitor tho, you may
increase it's life by turning it off when not in use.

 

[Plato]

Ignore this guy as he posts the rant and is wrong.

w_tom as long as I've known him, never flames, curses, etc. He just puts
in his opinion. He is a classic usenet poster ie a poster with a stong
opinion

 

[David Candy]

It wrong, it's been explained to him why. I pointed him to USAF documents on maintenance that refutes his thesis.