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

news:qOe%i.267005$lV4.257857@fe2.news.blueyonder.co.uk...

>

> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> news:473d5093$1_1@glkas0286.greenlnk.net...

> :

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

> : news:ZqT_i.74295$7_4.7509@fe3.news.blueyonder.co.uk...

> : >

> : > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> : > news:473bf94a$1_1@glkas0286.greenlnk.net...

> : > :

> : > : "Randy Poe" <poespam-trap@yahoo.com> wrote in message

> : > : news:1195056350.843348.184250@o3g2000hsb.googlegroups.com...

> : > : On Nov 14, 10:52 am, "Unknown" <unkn...@unknown.kom> wrote:

> : > : > How do you dream up all these ridiculous things?"M.I.5¾"

> : > : > <no....@no.where.NO_SPAM.co.uk> wrote in message

> : > : >

> : > : > news:473aab1e$1_1@glkas0286.greenlnk.net...

> : > : >

> : > : >

> : > : >

> : > : > > "Unknown" <unkn...@unknown.kom> wrote in message

> : > : > >news:SVj_i.68355$YL5.45228@newssvr29.news.prodigy.net...

> : > : > >> What type of capacitor has to cool off before it accepts a

> charge?

> : > : >

> : > : > > A: A faulty one.

> : > : >

> : > : > > It is well a known problem particularly among certain types of

> : > : > > electrolytic capacitors. The usual problem is that the EPR

> : > (Effective

> : > : > > parallel resistance) of the capacitor falls alarmingly as it

> warms

> : > up

> : > : > > rendering it ineffective as a capacitor.

> : > :

> : > : Two charts of electrolytic capacitor failure modes. Check out

> : > : Table 2 here:

> : > : http://industrial.panasonic.com/www-data/pdf/ABA0000/ABA0000TE4.pdf

> : > :

> : > : Operating at high temperature is shown to cause failure

> : > : by increase in leakage current.

> : > :

> : > : or Figure 2.10 here:

> : > :

> : >

> http://etd.gatech.edu/theses/available/etd-04082007-083102/unrestricted/imam_afroz_m_200705_phd.pdf

> : > :

> : > : Operating at high temperature is shown to cause failure

> : > : by loss of effective resistance (i.e. increased leakage).

> : > :

> : > : -----------

> : > :

> : > : Indeed. In general electrolytic capacitors are rated at either 85°C

> or

> : > : 105°C. The former is obviously cheaper than the latter and that's

> often

> : > : what gets used as such supplies don't run that warm. However, even

> if

> : > : operated below 85°C, the former type are considerably more

> unreliable

> : > than

> : > : the latter.

> : >

> : > Oh, so the latter break down at temperatures below 85°C because

> : > they are less reliable than the former cheaper ones... very logical.

> : >

> :

> : How you managed to arrive at that conclusion is anyone's guess.

>

> It's quite simple. Here's a table, you like tables.

>

> ------------------- Former ------------------ Latter ----------------

> < 85°C reliable unreliable

> > 85°C unreliable reliable

> _____________________________________________

>

 

Don't be pillock all your life, have a day off occasionally. I neither said

that nor inferred it. I stated that even when operated below 85°C,

capacitors rated at 85°C are more unreliable than those rated at 105°C.

"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...

 

No they are not. In the current (!) dicussion, they are used to smooth

voltage. That is not their only function however.

"sgopus" <sgopus@discussions.microsoft.com> wrote in message

news:3BBF9A4D-B9DE-4703-A6C3-BF585B4C4F30@microsoft.com...

> 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.

>

 

Some of us may have done. The relevance to this dicussion is what exactly?

" db ´¯`·.. ><)))º>` .. ." <databaseben.public.newsgroup.microsoft.com>

wrote in message news:u%23QYPAAIIHA.1184@TK2MSFTNGP04.phx.gbl...

> 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.

>

 

The greatest transient current taken by a motor is when it is at standstill,

but the drive electronics limits this to sensible proportions anyway. The

motors will actually take less transient current if repowered while still

rotating. The advice about allowing the drive to stop is sound, but is

actually unrelated to the motor.

On Fri, 16 Nov 2007 12:32:50 -0000, "M.I.5¾"

<no.one@no.where.NO_SPAM.co.uk> wrote:

>

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

>news:qOe%i.267005$lV4.257857@fe2.news.blueyonder.co.uk...

>>

>> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

>> news:473d5093$1_1@glkas0286.greenlnk.net...

>> :

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

>> : news:ZqT_i.74295$7_4.7509@fe3.news.blueyonder.co.uk...

>> : >

>> : > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

>> : > news:473bf94a$1_1@glkas0286.greenlnk.net...

>> : > :

>> : > : "Randy Poe" <poespam-trap@yahoo.com> wrote in message

>> : > : news:1195056350.843348.184250@o3g2000hsb.googlegroups.com...

>> : > : On Nov 14, 10:52 am, "Unknown" <unkn...@unknown.kom> wrote:

>> : > : > How do you dream up all these ridiculous things?"M.I.5¾"

>> : > : > <no....@no.where.NO_SPAM.co.uk> wrote in message

>> : > : >

>> : > : > news:473aab1e$1_1@glkas0286.greenlnk.net...

>> : > : >

>> : > : >

>> : > : >

>> : > : > > "Unknown" <unkn...@unknown.kom> wrote in message

>> : > : > >news:SVj_i.68355$YL5.45228@newssvr29.news.prodigy.net...

>> : > : > >> What type of capacitor has to cool off before it accepts a

>> charge?

>> : > : >

>> : > : > > A: A faulty one.

>> : > : >

>> : > : > > It is well a known problem particularly among certain types of

>> : > : > > electrolytic capacitors. The usual problem is that the EPR

>> : > (Effective

>> : > : > > parallel resistance) of the capacitor falls alarmingly as it

>> warms

>> : > up

>> : > : > > rendering it ineffective as a capacitor.

>> : > :

>> : > : Two charts of electrolytic capacitor failure modes. Check out

>> : > : Table 2 here:

>> : > : http://industrial.panasonic.com/www-data/pdf/ABA0000/ABA0000TE4.pdf

>> : > :

>> : > : Operating at high temperature is shown to cause failure

>> : > : by increase in leakage current.

>> : > :

>> : > : or Figure 2.10 here:

>> : > :

>> : >

>> http://etd.gatech.edu/theses/available/etd-04082007-083102/unrestricted/imam_afroz_m_200705_phd.pdf

>> : > :

>> : > : Operating at high temperature is shown to cause failure

>> : > : by loss of effective resistance (i.e. increased leakage).

>> : > :

>> : > : -----------

>> : > :

>> : > : Indeed. In general electrolytic capacitors are rated at either 85°C

>> or

>> : > : 105°C. The former is obviously cheaper than the latter and that's

>> often

>> : > : what gets used as such supplies don't run that warm. However, even

>> if

>> : > : operated below 85°C, the former type are considerably more

>> unreliable

>> : > than

>> : > : the latter.

>> : >

>> : > Oh, so the latter break down at temperatures below 85°C because

>> : > they are less reliable than the former cheaper ones... very logical.

>> : >

>> :

>> : How you managed to arrive at that conclusion is anyone's guess.

>>

>> It's quite simple. Here's a table, you like tables.

>>

>> ------------------- Former ------------------ Latter ----------------

>> < 85°C reliable unreliable

>> > 85°C unreliable reliable

>> _____________________________________________

>>

>

>Don't be pillock all your life, have a day off occasionally. I neither said

>that nor inferred it. I stated that even when operated below 85°C,

>capacitors rated at 85°C are more unreliable than those rated at 105°C.

>

 

 

With all due respect, are we on a crusade to prove who is right or to

help the now confused OP ?? Do you think the OP gave up on us? I

know at this point if I were him, I would have.

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!

 

Well, it's simple really, all of the viruses and malware that afflict

Microsoft operating systems have finally banded together to form a

neural net that has achieved sentience. The newly sentient entity has

now figured out a way to be able to horde electricity for background

operations even when the computer is off. It can send you Viagra notices

whenever it likes now. :-)

 

Yousuf Khan

"M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

news:473d8974$1_1@glkas0286.greenlnk.net...

:

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

: news:Ure%i.266961$lV4.48700@fe2.news.blueyonder.co.uk...

: >

: > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

: > news:473d500f$1_1@glkas0286.greenlnk.net...

: > :

: > : "w_tom" <w_tom1@usa.net> wrote in message

: > :

news:bd393d88-9656-4399-949b-ebb7a230e3a7@v4g2000hsf.googlegroups.com...

: > : > On Nov 15, 3:23 am, "M.I.5 3/4" <no....@no.where.NO_SPAM.co.uk>

wrote:

: > : >> All capacitor made are not equal - it's a fact of manufacturing.

: > About

: > : >> half

: > : >> the capacitors will work better than they were designed to, and the

: > other

: > : >> half will not work as well.

: > : >

: > : > Not quite correct. Almost all work at least as good as they were

: > : > designed for. Some will work far better. Cofidence levels - all

: > : > capacitors must at least meet specs - what they are intended to do.

: > : >

: > :

: > : You really don't know anything do you?

: > :

: > : Capacitors are produced is such large quantities that the conformance

to

: > : specification is done by testing a sample of each batch only. It is a

: > : fundamental requirement of sample testing that you have to accept that

: > items

: > : that do not conform to specification will be accepted. If you cannot

: > accept

: > : that then you can't do sample testing. Also, if you have a look at

any

: > : sample testing tables,

: >

: > Bwahahahahahah!

: > You really don't know anything about Quality Control, do you?

: >

:

: Probably more than you do sunshine.

:

: > Do these words mean anything to you: Mean, Variance, Standard Deviation?

: >

:

: Certainly do. Thats how sampling tables get produced in the first place.

 

Some of us have been QA Managers in our careers, moonshine, so

your "probably" has a probability of less than 0.0001.

 

Sample testing tables... hahahahaha!

Is that like log or sine tables, or have you heard of calculators and

computers in the Outback of Scotland, Northern Ireland or Wales yet?

 

You sure are not from the South East of England or the USA even

with a .co.uk email address or an allusion to MI5.

 

Sample testing tables... maybe Noah used them to select quality

timber for his ark. Too funny, moonshine, you are no bright

sunshine, are you?

"About half the capacitors will work better than they were designed

to, and the other

half will not work as well."

I wonder if you are playing with words.

"designed"

As opposed to the specifications potential customers are given.

They must meet the specifications or the customer has recourse.

Possible warranty replacement, legal action etc.

The lower half need to be appropriately packages and sold accordingly.

 

If I purchase a product with certain specifications, that is what I am

legally and otherwise entitled.

If half do not meet the design standard, then the specifications of

manufacture need to be raised or the documentation available to

customers needs to be lowered.

50% below documented specifications is simply unacceptable.

That is not to say anything less than 100% is unacceptable, but even

then the manufacturer may have to deal with returns/replacement of

substandard product.

 

--

Jupiter Jones [MVP]

http://www3.telus.net/dandemar

http://www.dts-l.org

 

 

"M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

news:473bfe40$1_1@glkas0286.greenlnk.net...

>

> "w_tom" <w_tom1@usa.net> wrote in message

> news:07825db1-85a6-4c24-aac4-e70825cdea78@w34g2000hsg.googlegroups.com...

>> On Nov 14, 2:56 pm, "Unknown" <unkn...@unknown.kom> wrote:

>>> Then the failure occurred BEFORE the capacitor went bad.

>>

>> Temperature has what relevance to the problem? Unfortunately,

>> many

>> want to blame temperature when other functions are not understood.

>>

>> Computers must work just fine even when room temperature is above

>> 100 degree F. In fact, testing a computer in a 100 degree room is

>> one

>> way to find defects because the defect results in failure.

>>

>> Electrolytic capacitors inside power supplies are typically rated

>> for higher temperatures. One failure mode is Effective Series

>> Resistance or ESR (not Parallel Resistance). If chemistry inside

>> the

>> electrolytic is failing, then series resistance increases. Higher

>> resistance means capacitor gets hotter - a feedback cycle that

>> eventually causes capacitor failure.

>>

>

> Both ESR and EPR are present in every capacitor made. ESR is

> usually quoted on spec sheets because every capacitor has this built

> in (it's a fact of the way they are designed). EPR, hopefully is

> not present to any extent that affects the operation of the

> capacitor. Although the ESR can rise, it is not a particularly

> common failure mode and is usually more due to mechanical

> construction than chemistry.

>

>> But this is not relevant to a power supply operating on 240 volts

>> AC

>> when the power supply is rated for 240 volts.

>>

>

> On the contrary, it is relevant to any circuit using capacitors.

>

>> Electrolytic failure is most often a manufacturing defect inside

>> the

>> capacitor or excessive voltage applied to that capacitor.

>> Capacitors

>> are routinely selected to withstand temperatures well above

>> standard

>> room temperature. Its temperature rating is usually printed on

>> that

>> electrolytic. Long before accepting what was posted, view those

>> numbers yourself.

>>

>

> All capacitor made are not equal - it's a fact of manufacturing.

> About half the capacitors will work better than they were designed

> to, and the other half will not work as well. A few will have

> manufacturing features that lead to some failure mode or other. An

> increase in the leakage (or a reduction in the EPR) is but one such

> mode of failure (but the most common, at least among electrolytic

> capacitors). In general, once the capacitor starts to leak

> excessively, the leakage will get worse as time progresses. It is a

> temperature dependant phenomenon.

>

> It is of course possible to manufacture capacitors that conform more

> closely to the intended design and have far fewer examples of

> failure (and indeed such are made). However, if they were used to

> build computer power supplies, nobody would be able to afford them.

> It's all a compromise between reliability and cost.

"RnR" <rnrtexas@gmail.com> wrote in message

news:t69rj3t5fh02s0ekvd56iqf3pka7tgph7c@4ax.com...

: On Fri, 16 Nov 2007 12:32:50 -0000, "M.I.5¾"

: <no.one@no.where.NO_SPAM.co.uk> wrote:

:

: >

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

: >news:qOe%i.267005$lV4.257857@fe2.news.blueyonder.co.uk...

: >>

: >> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

: >> news:473d5093$1_1@glkas0286.greenlnk.net...

: >> :

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

: >> : news:ZqT_i.74295$7_4.7509@fe3.news.blueyonder.co.uk...

: >> : >

: >> : > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

: >> : > news:473bf94a$1_1@glkas0286.greenlnk.net...

: >> : > :

: >> : > : "Randy Poe" <poespam-trap@yahoo.com> wrote in message

: >> : > : news:1195056350.843348.184250@o3g2000hsb.googlegroups.com...

: >> : > : On Nov 14, 10:52 am, "Unknown" <unkn...@unknown.kom> wrote:

: >> : > : > How do you dream up all these ridiculous things?"M.I.5¾"

: >> : > : > <no....@no.where.NO_SPAM.co.uk> wrote in message

: >> : > : >

: >> : > : > news:473aab1e$1_1@glkas0286.greenlnk.net...

: >> : > : >

: >> : > : >

: >> : > : >

: >> : > : > > "Unknown" <unkn...@unknown.kom> wrote in message

: >> : > : > >news:SVj_i.68355$YL5.45228@newssvr29.news.prodigy.net...

: >> : > : > >> What type of capacitor has to cool off before it accepts a

: >> charge?

: >> : > : >

: >> : > : > > A: A faulty one.

: >> : > : >

: >> : > : > > It is well a known problem particularly among certain types

of

: >> : > : > > electrolytic capacitors. The usual problem is that the EPR

: >> : > (Effective

: >> : > : > > parallel resistance) of the capacitor falls alarmingly as it

: >> warms

: >> : > up

: >> : > : > > rendering it ineffective as a capacitor.

: >> : > :

: >> : > : Two charts of electrolytic capacitor failure modes. Check out

: >> : > : Table 2 here:

: >> : > :

http://industrial.panasonic.com/www-data/pdf/ABA0000/ABA0000TE4.pdf

: >> : > :

: >> : > : Operating at high temperature is shown to cause failure

: >> : > : by increase in leakage current.

: >> : > :

: >> : > : or Figure 2.10 here:

: >> : > :

: >> : >

: >>

http://etd.gatech.edu/theses/available/etd-04082007-083102/unrestricted/imam_afroz_m_200705_phd.pdf

: >> : > :

: >> : > : Operating at high temperature is shown to cause failure

: >> : > : by loss of effective resistance (i.e. increased leakage).

: >> : > :

: >> : > : -----------

: >> : > :

: >> : > : Indeed. In general electrolytic capacitors are rated at either

85°C

: >> or

: >> : > : 105°C. The former is obviously cheaper than the latter and

that's

: >> often

: >> : > : what gets used as such supplies don't run that warm. However,

even

: >> if

: >> : > : operated below 85°C, the former type are considerably more

: >> unreliable

: >> : > than

: >> : > : the latter.

: >> : >

: >> : > Oh, so the latter break down at temperatures below 85°C because

: >> : > they are less reliable than the former cheaper ones... very

logical.

: >> : >

: >> :

: >> : How you managed to arrive at that conclusion is anyone's guess.

: >>

: >> It's quite simple. Here's a table, you like tables.

: >>

: >> ------------------- Former ------------------ Latter ----------------

: >> < 85°C reliable unreliable

: >> > 85°C unreliable reliable

: >> _____________________________________________

: >>

: >

: >Don't be pillock all your life, have a day off occasionally. I neither

said

: >that nor inferred it. I stated that even when operated below 85°C,

: >capacitors rated at 85°C are more unreliable than those rated at 105°C.

: >

:

:

: With all due respect, are we on a crusade to prove who is right or to

: help the now confused OP ?? Do you think the OP gave up on us? I

: know at this point if I were him, I would have.

 

If the OP doesn't have his answer by now he's in serious trouble.

This M.I.5¾ character seems to hallucinate that reliability is

a function of temperature without testing for failure rates

of 105°C rated capacitors at sub-zero temperatures, which

is the case for some military aircraft.

On Nov 5, 3:23 pm, Prisoner at War <prisoner_at_...@yahoo.com> wrote:

> 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????????????

 

I had a Dell notebook whose backlight just wouldn't go on. Removing

the batteries for an hour didn't help. Removing them for a week (while

I researched the process for disassembly and replacement of the HV

source) did! It was all good to go again. Glad I decided to give it

one more try before taking it apart.

 

Somehow it just didn't get the message that the top had been opened,

and it kept the light off thinking it was closed. Of course, I have no

evidence that an hour and a quarter wouldn't have done the job...or a

good bang with a small hammer.

 

Jim Deutch (JimboCat)

--

"If there were something supernatural, it would be completely

natural." -- Dave Slankard

Surely you don't think his head is THAT big?

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

news:89e%i.266926$lV4.238216@fe2.news.blueyonder.co.uk...

>

> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> news:473d4cc0$1_1@glkas0286.greenlnk.net...

> :

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

> : news:%7T_i.74198$7_4.66526@fe3.news.blueyonder.co.uk...

> : >

> : > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> : > news:473bf819$1_1@glkas0286.greenlnk.net...

> : > :

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

> : > : news:HXE_i.126189$vI1.83585@fe1.news.blueyonder.co.uk...

> : > : > Sounds like a short circuit to me. Perhaps he's connecting

> : > : > them with the wrong polarity of the "certain type".

> : > : >

> : > :

> : > : It's not a short circuit as such, just a lower resistance in

> parallel

> : >

> : > If you connect a copper wire or a solder splash across the cap

> : > you'd be connecting a lower resistance in parallel, even copper

> : > wire has some resistance. That's a short circuit by definition.

> : >

> :

> : So?

>

> So it is a short circuit of "the certain type" "as such", contrary to your

> hand-waving waffle. What's the 5¾ for? Not your hat size, surely?

>

>

On Nov 16, 3:24 am, "M.I.5 3/4" <no....@no.where.NO_SPAM.co.uk> wrote:

>> Not quite correct. Almost all work at least as good as they were

>> designed for. Some will work far better. Cofidence levels - all

>> capacitors must at least meet specs - what they are intended to do.

>

> You really don't know anything do you?

> Capacitors are produced is such large quantities that the conformance to

> specification is done by testing a sample of each batch only. It is a

> fundamental requirement of sample testing that you have to accept that

> items that do not conform to specification will be accepted. If you

> cannot accept that then you can't do sample testing.

 

Wow. First M.I.5 3/4 says I don't know anything. Then he explains the

process I specifically defined: Confidence Levels. Why do you

insult when the point is secondary and trivial;, and when Confidence

Levels are how virtually all manufacturer capacitors meet (or exceed)

specs.

 

Confidence Levels are why virtually all capacitors meet or exceed

specs. Do you know where your 'tables' come from? Please learn

about confidence levels. Sampling is part of the process so that

virtually all product meets or exceeds a spec. Charts are given to

those who don't have a clue beyond Mean, Variance, Standard Deviation.

- concepts from "Intro to Statistics'. Statistical Process Control

requires more education. Confidence Levels are why virtually all

capacitors meet or exceed manufacturer specs.

 

It is M.I.5 3/4 who "really don't know anything do you?" M.I.5 3/4 does

not even know what a Confidence Level is. So he insults others to

mask his ignorance rather than ask to learn. Then Bwahahs like a

baby who needs to be fed.

 

Meanwhile this (including M.I.5 3/4 ignorance of basic Statistical

Process Control) is irrelevant. Room temperature has nothing to do

with creating the OPs problem. Any PC that requires an air

conditioned room contains hardware defects.

Yes... and hollow. The distance between his ears is approximately

5¾"/pi ~= 1.67 with volume of empty space 2.44 cubic inches.

"Unknown" <unknown@unknown.kom> wrote in message

news:cmn%i.8262$3Z2.2292@nlpi069.nbdc.sbc.com...

: Surely you don't think his head is THAT big?

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

: news:89e%i.266926$lV4.238216@fe2.news.blueyonder.co.uk...

: >

: > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

: > news:473d4cc0$1_1@glkas0286.greenlnk.net...

: > :

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

: > : news:%7T_i.74198$7_4.66526@fe3.news.blueyonder.co.uk...

: > : >

: > : > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

: > : > news:473bf819$1_1@glkas0286.greenlnk.net...

: > : > :

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

: > : > : news:HXE_i.126189$vI1.83585@fe1.news.blueyonder.co.uk...

: > : > : > Sounds like a short circuit to me. Perhaps he's connecting

: > : > : > them with the wrong polarity of the "certain type".

: > : > : >

: > : > :

: > : > : It's not a short circuit as such, just a lower resistance in

: > parallel

: > : >

: > : > If you connect a copper wire or a solder splash across the cap

: > : > you'd be connecting a lower resistance in parallel, even copper

: > : > wire has some resistance. That's a short circuit by definition.

: > : >

: > :

: > : So?

: >

: > So it is a short circuit of "the certain type" "as such", contrary to

your

: > hand-waving waffle. What's the 5¾ for? Not your hat size, surely?

: >

: >

:

:

On Fri, 16 Nov 2007 09:34:38 -0800 (PST), JimboCat

<103134.3516@compuserve.com> wrote:

>On Nov 5, 3:23 pm, Prisoner at War <prisoner_at_...@yahoo.com> wrote:

>> 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????????????

>

>I had a Dell notebook whose backlight just wouldn't go on. Removing

>the batteries for an hour didn't help. Removing them for a week (while

>I researched the process for disassembly and replacement of the HV

>source) did! It was all good to go again. Glad I decided to give it

>one more try before taking it apart.

>

>Somehow it just didn't get the message that the top had been opened,

>and it kept the light off thinking it was closed. Of course, I have no

>evidence that an hour and a quarter wouldn't have done the job...or a

>good bang with a small hammer.

>

>Jim Deutch (JimboCat)

 

 

The "soft switch" of the laptop lid fired a transistor which turns the

HV source on.

 

Banging it with a hammer would merely produce a dent.

On Nov 6, 10:14 am, "Unknown" <unkn...@unknown.kom> wrote:

> No he's not. Capacitors do NOT smooth current. They reduce or eliminate

> voltage fluctuations.<nottooo..

 

Holy pulse capacitors. Batman!! Wanna try blowing something to hell??

Or maybe a good Marx generator will do.

On Mon, 05 Nov 2007 12:23:37 -0800, Prisoner at War

<prisoner_at_war@yahoo.com> wrote:

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

 

 

There is a such thing as an overtly crosspoting Usenet retard!

 

You qualify!

On Nov 5, 12:37 pm, "Gordon" <gbpli...@gmail.com.invalid> 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....

 

Capacitors store charge, not volts.

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

news:%233xB1RHKIHA.4684@TK2MSFTNGP06.phx.gbl...

> "About half the capacitors will work better than they were designed to,

> and the other

> half will not work as well."

> I wonder if you are playing with words.

> "designed"

> As opposed to the specifications potential customers are given.

> They must meet the specifications or the customer has recourse.

> Possible warranty replacement, legal action etc.

> The lower half need to be appropriately packages and sold accordingly.

>

> If I purchase a product with certain specifications, that is what I am

> legally and otherwise entitled.

> If half do not meet the design standard, then the specifications of

> manufacture need to be raised or the documentation available to customers

> needs to be lowered.

> 50% below documented specifications is simply unacceptable.

> That is not to say anything less than 100% is unacceptable, but even then

> the manufacturer may have to deal with returns/replacement of substandard

> product.

>

 

You are confusing what they are designed to do with what they are specified

to do. If you want all (or in practice the majority of) your produced

capacitors to meet or exceed what they are specified to do then you need to

design them to exceed that specification. When you come to manufacture

them, the process of manufacturing tolerances should ensure that on average,

they meet the design requirements. But by definition that average means

that half are better and half are worse (assuming a Gaussian distribution -

which it should be). The trick is ensuring that enough are better than the

published specification that your customers don't reject them. However,

whatever you do, there will always be a percentage (and hopefully a small

percentage) that fall outside of the published specification. How big that

percentage is depends on by how much you over engineer them.

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

news:Rik%i.85587$7_4.55313@fe3.news.blueyonder.co.uk...

>

> "RnR" <rnrtexas@gmail.com> wrote in message

> news:t69rj3t5fh02s0ekvd56iqf3pka7tgph7c@4ax.com...

> : On Fri, 16 Nov 2007 12:32:50 -0000, "M.I.5¾"

> : <no.one@no.where.NO_SPAM.co.uk> wrote:

> :

> : >

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

> : >news:qOe%i.267005$lV4.257857@fe2.news.blueyonder.co.uk...

> : >>

> : >> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> : >> news:473d5093$1_1@glkas0286.greenlnk.net...

> : >> :

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

> : >> : news:ZqT_i.74295$7_4.7509@fe3.news.blueyonder.co.uk...

> : >> : >

> : >> : > "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> : >> : > news:473bf94a$1_1@glkas0286.greenlnk.net...

> : >> : > :

> : >> : > : "Randy Poe" <poespam-trap@yahoo.com> wrote in message

> : >> : > : news:1195056350.843348.184250@o3g2000hsb.googlegroups.com...

> : >> : > : On Nov 14, 10:52 am, "Unknown" <unkn...@unknown.kom> wrote:

> : >> : > : > How do you dream up all these ridiculous things?"M.I.5¾"

> : >> : > : > <no....@no.where.NO_SPAM.co.uk> wrote in message

> : >> : > : >

> : >> : > : > news:473aab1e$1_1@glkas0286.greenlnk.net...

> : >> : > : >

> : >> : > : >

> : >> : > : >

> : >> : > : > > "Unknown" <unkn...@unknown.kom> wrote in message

> : >> : > : > >news:SVj_i.68355$YL5.45228@newssvr29.news.prodigy.net...

> : >> : > : > >> What type of capacitor has to cool off before it accepts a

> : >> charge?

> : >> : > : >

> : >> : > : > > A: A faulty one.

> : >> : > : >

> : >> : > : > > It is well a known problem particularly among certain types

> of

> : >> : > : > > electrolytic capacitors. The usual problem is that the EPR

> : >> : > (Effective

> : >> : > : > > parallel resistance) of the capacitor falls alarmingly as

> it

> : >> warms

> : >> : > up

> : >> : > : > > rendering it ineffective as a capacitor.

> : >> : > :

> : >> : > : Two charts of electrolytic capacitor failure modes. Check out

> : >> : > : Table 2 here:

> : >> : > :

> http://industrial.panasonic.com/www-data/pdf/ABA0000/ABA0000TE4.pdf

> : >> : > :

> : >> : > : Operating at high temperature is shown to cause failure

> : >> : > : by increase in leakage current.

> : >> : > :

> : >> : > : or Figure 2.10 here:

> : >> : > :

> : >> : >

> : >>

> http://etd.gatech.edu/theses/available/etd-04082007-083102/unrestricted/imam_afroz_m_200705_phd.pdf

> : >> : > :

> : >> : > : Operating at high temperature is shown to cause failure

> : >> : > : by loss of effective resistance (i.e. increased leakage).

> : >> : > :

> : >> : > : -----------

> : >> : > :

> : >> : > : Indeed. In general electrolytic capacitors are rated at either

> 85°C

> : >> or

> : >> : > : 105°C. The former is obviously cheaper than the latter and

> that's

> : >> often

> : >> : > : what gets used as such supplies don't run that warm. However,

> even

> : >> if

> : >> : > : operated below 85°C, the former type are considerably more

> : >> unreliable

> : >> : > than

> : >> : > : the latter.

> : >> : >

> : >> : > Oh, so the latter break down at temperatures below 85°C because

> : >> : > they are less reliable than the former cheaper ones... very

> logical.

> : >> : >

> : >> :

> : >> : How you managed to arrive at that conclusion is anyone's guess.

> : >>

> : >> It's quite simple. Here's a table, you like tables.

> : >>

> : >> ------------------- Former ------------------

> Latter ----------------

> : >> < 85°C reliable unreliable

> : >> > 85°C unreliable reliable

> : >> _____________________________________________

> : >>

> : >

> : >Don't be pillock all your life, have a day off occasionally. I neither

> said

> : >that nor inferred it. I stated that even when operated below 85°C,

> : >capacitors rated at 85°C are more unreliable than those rated at 105°C.

> : >

> :

> :

> : With all due respect, are we on a crusade to prove who is right or to

> : help the now confused OP ?? Do you think the OP gave up on us? I

> : know at this point if I were him, I would have.

>

> If the OP doesn't have his answer by now he's in serious trouble.

> This M.I.5¾ character seems to hallucinate that reliability is

> a function of temperature without testing for failure rates

> of 105°C rated capacitors at sub-zero temperatures, which

> is the case for some military aircraft.

>

 

Thus proving beyond all reasonable doubt that you are imagining content in

my posts that simply isn't there.

 

I think the kill file beckons. Ah 'tis done.

Read my post again, it seems you missed most of it.

 

--

Jupiter Jones [MVP]

http://www3.telus.net/dandemar

http://www.dts-l.org

 

 

"M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

news:474141a2$1_1@glkas0286.greenlnk.net...

> You are confusing what they are designed to do with what they are

> specified to do. If you want all (or in practice the majority of)

> your produced capacitors to meet or exceed what they are specified

> to do then you need to design them to exceed that specification.

> When you come to manufacture them, the process of manufacturing

> tolerances should ensure that on average, they meet the design

> requirements. But by definition that average means that half are

> better and half are worse (assuming a Gaussian distribution - which

> it should be). The trick is ensuring that enough are better than

> the published specification that your customers don't reject them.

> However, whatever you do, there will always be a percentage (and

> hopefully a small percentage) that fall outside of the published

> specification. How big that percentage is depends on by how much

> you over engineer them.

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

news:uhDkzRsKIHA.3400@TK2MSFTNGP03.phx.gbl...

> Read my post again, it seems you missed most of it.

>

 

No I didn't.

> --

> Jupiter Jones [MVP]

> http://www3.telus.net/dandemar

> http://www.dts-l.org

>

>

> "M.I.5¾" <no.one@no.where.NO_SPAM.co.uk> wrote in message

> news:474141a2$1_1@glkas0286.greenlnk.net...

>> You are confusing what they are designed to do with what they are

>> specified to do. If you want all (or in practice the majority of) your

>> produced capacitors to meet or exceed what they are specified to do then

>> you need to design them to exceed that specification. When you come to

>> manufacture them, the process of manufacturing tolerances should ensure

>> that on average, they meet the design requirements. But by definition

>> that average means that half are better and half are worse (assuming a

>> Gaussian distribution - which it should be). The trick is ensuring that

>> enough are better than the published specification that your customers

>> don't reject them. However, whatever you do, there will always be a

>> percentage (and hopefully a small percentage) that fall outside of the

>> published specification. How big that percentage is depends on by how

>> much you over engineer them.

>