Holy Moly -- Residual Electricity????

Discussion in 'Dell' started by Prisoner at War, Nov 5, 2007.

  1. Prisoner at War

    Androcles Guest

    :
    : : > 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.
     
    Androcles, Nov 15, 2007
    #81
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  2. Prisoner at War

    M.I.5¾ Guest

    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.
    On the contrary, it is relevant to any circuit using capacitors.
    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.
     
    M.I.5¾, Nov 15, 2007
    #82
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  3. Prisoner at War

    Androcles Guest

    :
    : : > How do you dream up all these ridiculous things?"M.I.5¾"
    : >
    : > : >
    : >
    : >
    : > >: > >> 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.
     
    Androcles, Nov 15, 2007
    #83
  4. Prisoner at War

    M.I.5¾ Guest

    The particular temperatures we are talking here are not unusual
    temperatures, but the usual temperature excursions experienced by components
    in any circuit while it is operating. Any operating circuit has current
    flowing in its parts and this generates heat. The capacitors we are
    concerned with are not experiencing heat outside of their design range, but
    rather the capacitors are unable tolerate even this design heat because of
    adverse manufacturing tolerances or possibly even that he capacitor has been
    subject to a transient event that has reduced its ability to withstand such
    heat (for example a voltage spike that partially breaks down the dielectric
    layer).
     
    M.I.5¾, Nov 15, 2007
    #84
  5. Prisoner at War

    Unknown Guest

    BS
     
    Unknown, Nov 15, 2007
    #85
  6. Prisoner at War

    w_tom Guest

    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.

    The primary source of heating is ESR. ESR increases as the capactor
    fails causing even more heat. And all that is completely irrelevant
    to the OPs question. That computer must work just fine even when the
    70 degree room rises to above 100 degree F. Again, what is the
    temperature printed on that capacitor's label?
     
    w_tom, Nov 15, 2007
    #86
  7. Prisoner at War

    M.I.5¾ Guest

    So?

    I doubt that the OP has done that.
     
    M.I.5¾, Nov 16, 2007
    #87
  8. Prisoner at War

    M.I.5¾ Guest

    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, you will see that in most of them failures are
    allowed, but the batch can still be accepted. There are tables that allow
    no failures, but that does not prevent failures from occuring in the
    majority (untested) part of the batch.

    The BS6001 series of standards would be a good starting point.
    ESR is but one source of heating and usually (or should be) the most
    insignificant. The primary sources of heating are all the heat disipating
    components around the capacitor. ESR does not necessarily increase as the
    capacitor fails, but a reduced EPR can also be a source of internally
    generated heat, but only if the rest of the circuit permits enough current
    to flow for it to become a factor.
    I have already addressed this point. Try reading the rest of the thread.
     
    M.I.5¾, Nov 16, 2007
    #88
  9. Prisoner at War

    M.I.5¾ Guest

    How you managed to arrive at that conclusion is anyone's guess.
     
    M.I.5¾, Nov 16, 2007
    #89
  10. Prisoner at War

    Androcles Guest

    :
    : : >
    : > : > :
    : > : : > : > 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?
     
    Androcles, Nov 16, 2007
    #90
  11. Prisoner at War

    Androcles Guest

    :
    : : >> 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?

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

    Tables! Got any sample testing chairs to go with them, size 5¾ ?
    HAHAHAHAHAHA!
     
    Androcles, Nov 16, 2007
    #91
  12. Prisoner at War

    Androcles Guest

    :
    : : >
    : > : > :
    : > : : > : > How do you dream up all these ridiculous things?"M.I.5¾"
    : > : >
    : > : > : > : >
    : > : >
    : > : >
    : > : > >: > : > >> 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
    _____________________________________________
     
    Androcles, Nov 16, 2007
    #92
  13. Prisoner at War

    M.I.5¾ Guest

    Probably more than you do sunshine.
    Certainly do. Thats how sampling tables get produced in the first place.
     
    M.I.5¾, Nov 16, 2007
    #93
  14. Prisoner at War

    M.I.5¾ Guest

    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.
     
    M.I.5¾, Nov 16, 2007
    #94
  15. Prisoner at War

    M.I.5¾ Guest

    No they are not. In the current (!) dicussion, they are used to smooth
    voltage. That is not their only function however.
     
    M.I.5¾, Nov 16, 2007
    #95
  16. Prisoner at War

    RnR Guest


    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.
     
    RnR, Nov 16, 2007
    #96
  17. Prisoner at War

    Yousuf Khan Guest

    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
     
    Yousuf Khan, Nov 16, 2007
    #97
  18. Prisoner at War

    Androcles Guest

    :
    : : >
    : > : > :
    : > :
    : > : > On Nov 15, 3:23 am, "M.I.5 3/4" <_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?
     
    Androcles, Nov 16, 2007
    #98
  19. Prisoner at War

    Androcles Guest

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


    Don't be a **** all your life, you haven't much data for the reliability
    of 105°C rated capacitors operated in ambient temperatures.
    You'll be telling us next that low power Schottky TTL is reliable,
    and that's crap.
     
    Androcles, Nov 16, 2007
    #99
  20. Prisoner at War

    Androcles Guest

    : On Fri, 16 Nov 2007 12:32:50 -0000, "M.I.5¾"
    :
    : >
    : >: >>
    : >> : >> :
    : >> : : >> : >
    : >> : > : >> : > :
    : >> : > : : >> : > : > How do you dream up all these ridiculous things?"M.I.5¾"
    : >> : > : >
    : >> : > : > : >> : > : >
    : >> : > : >
    : >> : > : >
    : >> : > : > >: >> : > : > >> 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.
     
    Androcles, Nov 16, 2007
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