Is there some such concept as "residual electricity"???

 

There was a problem with a computer at work...it's a new Dell running

WinXP Pro...everything's fine, I go to lunch and come back to a blank

screen that won't wake up from power-save/sleep mode!! I do the

obvious and check connections, making sure they're secure and

whatnot. I turn off the computer and turn it back on a few times, to

no effect!

 

Tech Support suspects some kind of a "power management" issue --

whatever that is -- and suggests that I leave the system off for a few

minutes, literally, to let things "clear"...whatever that means. Sure

enough, however: it works!

 

So now I'm here asking, because Tech hasn't the time to puzzle over it

with me, WHAT HAPPENED??? And how come shutting off power for a few

seconds isn't comparable to leaving power off for a few

minutes????????????

 

TIA!

In sci.physics Prisoner at War . wrote:

> Is there some such concept as "residual electricity"???

> There was a problem with a computer at work...it's a new Dell running

> WinXP Pro...everything's fine, I go to lunch and come back to a blank

> screen that won't wake up from power-save/sleep mode!! I do the

> obvious and check connections, making sure they're secure and

> whatnot. I turn off the computer and turn it back on a few times, to

> no effect!

> Tech Support suspects some kind of a "power management" issue --

> whatever that is -- and suggests that I leave the system off for a few

> minutes, literally, to let things "clear"...whatever that means. Sure

> enough, however: it works!

> So now I'm here asking, because Tech hasn't the time to puzzle over it

> with me, WHAT HAPPENED??? And how come shutting off power for a few

> seconds isn't comparable to leaving power off for a few

> minutes????????????

> TIA!

 

Capacitors.

 

--

Jim Pennino

 

Remove .spam.sux to reply.

<jimp@specsol.spam.sux.com> wrote in message

news:p4b405-rog.ln1@mail.specsol.com...

>

> Capacitors.

>

 

 

capacitors usually discharge when the current is switched off - their main

job is to smooth current, not to store volts....

When you turn it off and leave it off for a few minutes, it allows the

capacitors in the power supply to discharge.

With the power supply caps discharged, you in effect are guaranteeing a good

power on reset when you power on.

"Prisoner at War" . wrote in message

news:1194294217.473003.148980@y42g2000hsy.googlegroups.com...

>

> Is there some such concept as "residual electricity"???

>

> There was a problem with a computer at work...it's a new Dell running

> WinXP Pro...everything's fine, I go to lunch and come back to a blank

> screen that won't wake up from power-save/sleep mode!! I do the

> obvious and check connections, making sure they're secure and

> whatnot. I turn off the computer and turn it back on a few times, to

> no effect!

>

> Tech Support suspects some kind of a "power management" issue --

> whatever that is -- and suggests that I leave the system off for a few

> minutes, literally, to let things "clear"...whatever that means. Sure

> enough, however: it works!

>

> So now I'm here asking, because Tech hasn't the time to puzzle over it

> with me, WHAT HAPPENED??? And how come shutting off power for a few

> seconds isn't comparable to leaving power off for a few

> minutes????????????

>

> TIA!

>

They discharge, but it can take some time depending on the capacitors.

A few minutes is not at all unusual.

 

--

Jupiter Jones

http://www3.telus.net/dandemar

http://www.dts-l.org

 

 

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgnuv5$o29$1@news.mixmin.net...

> capacitors usually discharge when the current is switched off -

> their main job is to smooth current, not to store volts....

Gordon wrote:

> <jimp@specsol.spam.sux.com> wrote in message

> news:p4b405-rog.ln1@mail.specsol.com...

>> Capacitors.

>>

>

>

> capacitors usually discharge when the current is switched off - their main

> job is to smooth current, not to store volts....

>

>

 

True, but they don't discharge instantaneously. Ever hear about the

"time constant" of an R-C circuit?

 

T = R × C

where:

T = time constant in seconds

R = resistance in ohms

C = capacitance in farads

 

The time constant is the time taken for the charging (or discharging)

current (I) to fall to 1/e of its initial value (Io).

 

After each time constant the current falls by 1/e (about 1/3). After 5

time constants (5RC) the current has fallen to less than 1% of its

initial value and we can reasonably say that the capacitor is fully

(dis)charged, but in fact the capacitor takes for ever to (dis)charge

fully!

 

--

Lem -- MS-MVP - Networking

 

To the moon and back with 4KB of RAM and 72KB of ROM.

http://en.wikipedia.org/wiki/Apollo_Guidance_Computer

http://history.nasa.gov/afj/compessay.htm

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgnuv5$o29$1@news.mixmin.net...

> <jimp@specsol.spam.sux.com> wrote in message

> news:p4b405-rog.ln1@mail.specsol.com...

>>

>> Capacitors.

>>

>

>

> capacitors usually discharge when the current is switched off - their main

> job is to smooth current, not to store volts....

 

Capacitors don't store "volts" - they store "Coulombs".

Volt is a measure for "voltage" (or "electrical tension").

Coulomb is a measure for electrical charge. The main

purpose of a capacitor is not to smooth current but to

keep the voltage constant, regardless of the current

supplied or drawn.

"Jupiter Jones" <jones_jupiter@hotnomail.com> wrote in message

news:1xLXi.29858$XF6.22011@edtnps90...

> They discharge, but it can take some time depending on the capacitors.

> A few minutes is not at all unusual.

 

You can get some nasty burns from a TV that's unplugged due to those

things!

 

Tom Lake

"Pegasus (MVP)" <I.can@fly.com> wrote in message

news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

> Capacitors don't store "volts" - they store "Coulombs".

> Volt is a measure for "voltage" (or "electrical tension").

> Coulomb is a measure for electrical charge. The main

> purpose of a capacitor is not to smooth current but to

> keep the voltage constant, regardless of the current

> supplied or drawn.

>

 

I did Physics A level in 1973!

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgnuv5$o29$1@news.mixmin.net...

: <jimp@specsol.spam.sux.com> wrote in message

: news:p4b405-rog.ln1@mail.specsol.com...

: >

: > Capacitors.

: >

:

:

: capacitors usually discharge when the current is switched off - their main

: job is to smooth current, not to store volts....

 

That shows how much you know -- which is zilch.

"Androcles" <Engineer@hogwarts.physics> wrote in message

news:neMXi.225829$lV4.46015@fe2.news.blueyonder.co.uk...

>

> "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> news:fgnuv5$o29$1@news.mixmin.net...

> : <jimp@specsol.spam.sux.com> wrote in message

> : news:p4b405-rog.ln1@mail.specsol.com...

> : >

> : > Capacitors.

> : >

> :

> :

> : capacitors usually discharge when the current is switched off - their

> main

> : job is to smooth current, not to store volts....

>

> That shows how much you know -- which is zilch.

>

>

 

 

Well rooty toot to you.

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgo384$rvp$1@news.mixmin.net...

: "Androcles" <Engineer@hogwarts.physics> wrote in message

: news:neMXi.225829$lV4.46015@fe2.news.blueyonder.co.uk...

: >

: > "Gordon" <gbplinux@gmail.com.invalid> wrote in message

: > news:fgnuv5$o29$1@news.mixmin.net...

: > : <jimp@specsol.spam.sux.com> wrote in message

: > : news:p4b405-rog.ln1@mail.specsol.com...

: > : >

: > : > Capacitors.

: > : >

: > :

: > :

: > : capacitors usually discharge when the current is switched off - their

: > main

: > : job is to smooth current, not to store volts....

: >

: > That shows how much you know -- which is zilch.

: >

: >

:

:

: Well rooty toot to you.

 

That shows just how childish you are.

"Androcles" <Engineer@hogwarts.physics> wrote in message

news:MlMXi.225857$lV4.213311@fe2.news.blueyonder.co.uk...

>

> "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> news:fgo384$rvp$1@news.mixmin.net...

> : "Androcles" <Engineer@hogwarts.physics> wrote in message

> : news:neMXi.225829$lV4.46015@fe2.news.blueyonder.co.uk...

> : >

> : > "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> : > news:fgnuv5$o29$1@news.mixmin.net...

> : > : <jimp@specsol.spam.sux.com> wrote in message

> : > : news:p4b405-rog.ln1@mail.specsol.com...

> : > : >

> : > : > Capacitors.

> : > : >

> : > :

> : > :

> : > : capacitors usually discharge when the current is switched off -

> their

> : > main

> : > : job is to smooth current, not to store volts....

> : >

> : > That shows how much you know -- which is zilch.

> : >

> : >

> :

> :

> : Well rooty toot to you.

>

> That shows just how childish you are.

>

>

 

Sod you you arrogant ignorant moron.

Capacitors ARE used to smooth current so just crawl back under your slimy

rock...

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgo2ga$r8n$1@news.mixmin.net...

> "Pegasus (MVP)" <I.can@fly.com> wrote in message

> news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

>> Capacitors don't store "volts" - they store "Coulombs".

>> Volt is a measure for "voltage" (or "electrical tension").

>> Coulomb is a measure for electrical charge. The main

>> purpose of a capacitor is not to smooth current but to

>> keep the voltage constant, regardless of the current

>> supplied or drawn.

>>

>

> I did Physics A level in 1973!

 

Then you need to be careful with capacitors, to avoid

getting zapped! :-)

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgo2ga$r8n$1@news.mixmin.net...

> "Pegasus (MVP)" <I.can@fly.com> wrote in message

> news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

>> Capacitors don't store "volts" - they store "Coulombs".

>> Volt is a measure for "voltage" (or "electrical tension").

>> Coulomb is a measure for electrical charge. The main

>> purpose of a capacitor is not to smooth current but to

>> keep the voltage constant, regardless of the current

>> supplied or drawn.

>>

>

> I did Physics A level in 1973!

>

>

>

Well, I studied College Physics in 1949, but I still know that a capacitor

stores energy not voltage. Coulomb is a measure of electrical energy.

 

Jim

Gordon wrote:

> "Pegasus (MVP)" <I.can@fly.com> wrote in message

> news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

>> Capacitors don't store "volts" - they store "Coulombs".

>> Volt is a measure for "voltage" (or "electrical tension").

>> Coulomb is a measure for electrical charge. The main

>> purpose of a capacitor is not to smooth current but to

>> keep the voltage constant, regardless of the current

>> supplied or drawn.

>>

>

> I did Physics A level in 1973!

>

>

>

I'm way ahead of you. Physics 1 in Fall 1949, Physics 2 is Spring 1950,

grades D and A respectively. And, no, I don't remember what we covered

in each semester...

 

Bill

"Jim" <j.n@nospam.com> wrote in message

news:uBMXi.63421$Um6.3739@newssvr12.news.prodigy.net...

>

> "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> news:fgo2ga$r8n$1@news.mixmin.net...

>> "Pegasus (MVP)" <I.can@fly.com> wrote in message

>> news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

>>> Capacitors don't store "volts" - they store "Coulombs".

>>> Volt is a measure for "voltage" (or "electrical tension").

>>> Coulomb is a measure for electrical charge. The main

>>> purpose of a capacitor is not to smooth current but to

>>> keep the voltage constant, regardless of the current

>>> supplied or drawn.

>>>

>>

>> I did Physics A level in 1973!

>>

>>

>>

> Well, I studied College Physics in 1949, but I still know that a capacitor

> stores energy not voltage. Coulomb is a measure of electrical energy.

>

> Jim

 

Nope. Coulomb is a measure of electrical charge. Joule (or Watt-second)

is a measure of electrical energy.

"Gordon" <gbplinux@gmail.com.invalid> wrote in message

news:fgo41g$sqb$1@news.mixmin.net...

: "Androcles" <Engineer@hogwarts.physics> wrote in message

: news:MlMXi.225857$lV4.213311@fe2.news.blueyonder.co.uk...

: >

: > "Gordon" <gbplinux@gmail.com.invalid> wrote in message

: > news:fgo384$rvp$1@news.mixmin.net...

: > : "Androcles" <Engineer@hogwarts.physics> wrote in message

: > : news:neMXi.225829$lV4.46015@fe2.news.blueyonder.co.uk...

: > : >

: > : > "Gordon" <gbplinux@gmail.com.invalid> wrote in message

: > : > news:fgnuv5$o29$1@news.mixmin.net...

: > : > : <jimp@specsol.spam.sux.com> wrote in message

: > : > : news:p4b405-rog.ln1@mail.specsol.com...

: > : > : >

: > : > : > Capacitors.

: > : > : >

: > : > :

: > : > :

: > : > : capacitors usually discharge when the current is switched off -

: > their

: > : > main

: > : > : job is to smooth current, not to store volts....

: > : >

: > : > That shows how much you know -- which is zilch.

: > : >

: > : >

: > :

: > :

: > : Well rooty toot to you.

: >

: > That shows just how childish you are.

: >

: >

:

: Sod you you arrogant ignorant moron.

: Capacitors ARE used to smooth current so just crawl back under your slimy

: rock...

 

That shows just how stupid you really are, you don't even know

the difference between voltage and current.

HAHAHA!

Technically, caps store electricity and discharge it, at a specified rate.

and yes they can store it like a battery.

 

"Gordon" wrote:

> <jimp@specsol.spam.sux.com> wrote in message

> news:p4b405-rog.ln1@mail.specsol.com...

> >

> > Capacitors.

> >

>

>

> capacitors usually discharge when the current is switched off - their main

> job is to smooth current, not to store volts....

>

>

>

I'm sure you guys have heard of starting caps???

used when you have a high horsepower electrical motor that needs a high

surge just when starting?? like motors used in freezers, or heat pumps, same

concept.

can we save the insults, and have a regular discussion, not an arguement.

 

 

"Androcles" wrote:

>

> "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> news:fgo384$rvp$1@news.mixmin.net...

> : "Androcles" <Engineer@hogwarts.physics> wrote in message

> : news:neMXi.225829$lV4.46015@fe2.news.blueyonder.co.uk...

> : >

> : > "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> : > news:fgnuv5$o29$1@news.mixmin.net...

> : > : <jimp@specsol.spam.sux.com> wrote in message

> : > : news:p4b405-rog.ln1@mail.specsol.com...

> : > : >

> : > : > Capacitors.

> : > : >

> : > :

> : > :

> : > : capacitors usually discharge when the current is switched off - their

> : > main

> : > : job is to smooth current, not to store volts....

> : >

> : > That shows how much you know -- which is zilch.

> : >

> : >

> :

> :

> : Well rooty toot to you.

>

> That shows just how childish you are.

>

>

>

"Jim" <j.n@nospam.com> wrote in message

news:uBMXi.63421$Um6.3739@newssvr12.news.prodigy.net...

>

> "Gordon" <gbplinux@gmail.com.invalid> wrote in message

> news:fgo2ga$r8n$1@news.mixmin.net...

>> "Pegasus (MVP)" <I.can@fly.com> wrote in message

>> news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

>>> Capacitors don't store "volts" - they store "Coulombs".

>>> Volt is a measure for "voltage" (or "electrical

>>> tension").

>>> Coulomb is a measure for electrical charge. The main

>>> purpose of a capacitor is not to smooth current but to

>>> keep the voltage constant, regardless of the current

>>> supplied or drawn.

>>>

>>

>> I did Physics A level in 1973!

>>

>>

>>

> Well, I studied College Physics in 1949, but I still know

> that a capacitor stores energy not voltage. Coulomb is a

> measure of electrical energy.

>

> Jim

Energy= 1/2(C*V^2)

On Nov 5, 12:27 pm, Lem <lem...@hotmail.com> wrote:

> Gordon wrote:

> > <j...@specsol.spam.sux.com> wrote in message

> >news:p4b405-rog.ln1@mail.specsol.com...

> >> Capacitors.

>

> > capacitors usually discharge when the current is switched off - their main

> > job is to smooth current, not to store volts....

>

> True, but they don't discharge instantaneously. Ever hear about the

> "time constant" of an R-C circuit?

>

> T = R × C

> where:

> T = time constant in seconds

> R = resistance in ohms

> C = capacitance in farads

>

> The time constant is the time taken for the charging (or discharging)

> current (I) to fall to 1/e of its initial value (Io).

>

> After each time constant the current falls by 1/e (about 1/3). After 5

> time constants (5RC) the current has fallen to less than 1% of its

> initial value and we can reasonably say that the capacitor is fully

> (dis)charged, but in fact the capacitor takes for ever to (dis)charge

> fully!

>

> --

> Lem -- MS-MVP - Networking

>

> To the moon and back with 4KB of RAM and 72KB of ROM.http://en.wikipedia.org/wiki/Apollo_Guidance_Computerhttp://history.nasa.gov/afj/compessay.htm

 

Yes,To the moon and back with 4KB of RAM and 72KB of ROM.

So why can't some one harness nuclear fusion for our energy needs?

Bill Sharpe wrote:

> Gordon wrote:

>> "Pegasus (MVP)" <I.can@fly.com> wrote in message

>> news:eBvWUM$HIHA.4688@TK2MSFTNGP06.phx.gbl...

>>> Capacitors don't store "volts" - they store "Coulombs".

>>> Volt is a measure for "voltage" (or "electrical tension").

>>> Coulomb is a measure for electrical charge. The main

>>> purpose of a capacitor is not to smooth current but to

>>> keep the voltage constant, regardless of the current

>>> supplied or drawn.

>>>

>>

>> I did Physics A level in 1973!

>>

>>

>>

> I'm way ahead of you. Physics 1 in Fall 1949, Physics 2 is Spring

> 1950, grades D and A respectively. And, no, I don't remember what we

> covered in each semester...

>

 

Semester 1: Mechanics

Semester 2: Heat, Light, Sound

Semester 3: Electricity & Magnetism

 

No, wait...

Prisoner at War wrote:

> Is there some such concept as "residual electricity"???

>

> There was a problem with a computer at work...it's a new Dell running

> WinXP Pro...everything's fine, I go to lunch and come back to a blank

> screen that won't wake up from power-save/sleep mode!! I do the

> obvious and check connections, making sure they're secure and

> whatnot. I turn off the computer and turn it back on a few times, to

> no effect!

>

> Tech Support suspects some kind of a "power management" issue --

> whatever that is -- and suggests that I leave the system off for a few

> minutes, literally, to let things "clear"...whatever that means. Sure

> enough, however: it works!

>

> So now I'm here asking, because Tech hasn't the time to puzzle over it

> with me, WHAT HAPPENED??? And how come shutting off power for a few

> seconds isn't comparable to leaving power off for a few

> minutes????????????

>

 

You're going to get a lot of theory here, but the real answer is: The power

supply's broke.

Well,

 

when the pc is powered down

it is important to wait for

the disks inside the hard drive(s)

to stop spinning before powering

them up again. Usually 20 seconds

is good waiting period before

powering your pc up again.

 

This helps prevents a surge

and reduces the wear and tear

on those tiny little motors.

 

As for the residual electricity

it depends on what kind of

capacitors they are.

 

They are designed with different

specifications. Some hold large

charges of electricity and some hold

miniscule amounts. Some are designed

to release their charges frequently

while others are designed to hold

them until something or someone

grounds them.

 

However the above on

residual electricity is only

a consideration when accessing

the internals of pc.

 

Electronics are not unlike

light bulbs, in that they can

handle being turned on and off

frequently. However, the

motors need time to

slow down and stop before

powering them again.

 

--

 

db ·´¯`·.¸. , . .·´¯`·..><)))º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><)))º>¸.

><)))º>·´¯`·.¸. , . .·´¯`·.. ><)))º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><)))º>

 

 

..

 

 

"Prisoner at War" . wrote in message

news:1194294217.473003.148980@y42g2000hsy.googlegroups.com...

>

> Is there some such concept as "residual electricity"???

>

> There was a problem with a computer at work...it's a new Dell running

> WinXP Pro...everything's fine, I go to lunch and come back to a blank

> screen that won't wake up from power-save/sleep mode!! I do the

> obvious and check connections, making sure they're secure and

> whatnot. I turn off the computer and turn it back on a few times, to

> no effect!

>

> Tech Support suspects some kind of a "power management" issue --

> whatever that is -- and suggests that I leave the system off for a few

> minutes, literally, to let things "clear"...whatever that means. Sure

> enough, however: it works!

>

> So now I'm here asking, because Tech hasn't the time to puzzle over it

> with me, WHAT HAPPENED??? And how come shutting off power for a few

> seconds isn't comparable to leaving power off for a few

> minutes????????????

>

> TIA!

>