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Electrolytic capacitors

Discussion in 'Hobby Electronics' started by Peter Howard, Feb 9, 2006.

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  1. Peter Howard

    Peter Howard Guest

    I've just had a tiny triumph by resuscitating a small format ATX PC power
    supply, mainly by replacing all the obviously bulged electros first, then
    every other electro. All with mail order low-esr types. Fortunately, the
    supply was all through hole construction, not SM. Would not have bothered
    except that the small format supplies as found in many mini-tower boxes are
    considerably more costly than a generic standard sized supply.
    Anyway, I've become interested in electros and esr to the extent of buying a
    Bob Parker MkII ESR meter kit, on special this month at Tricky Dicks.Still
    being assembled.

    Questions arise.
    (1) I like to have a few dozen common electros on hand in the parts box. All
    I can get locally is standard esr types. Anything to be said for paying a
    little more and standardizing on low-esr types by mail-order? Is a low-esr
    type necessarily better quality and longer lasting?

    (2) From studying the RS and Farnell catalogues I notice that they have a
    more limited range of low-esr types. For instance, the smallest 10uf type I
    find is 25VW versus 16VW for "standard" type. What is the experts practical
    experience of selecting working voltage? I Googled the topic and I found
    little in the way of practical advice. For instance, if I want to place a
    filter cap after a 12v 3term regulator, I'd probably choose one of
    appropriate capacitance and 16VW. What about 25VW? Or 35VW or 63VW?
    Obviously, I would not use a cap of 300VW as I think I understand that
    choosing too high a VW won't permit the dielectric film to be maintained.
    What I need is a practical rule-of-thumb.

    (3) Lots of my parts box electros are small unsused bargain-bag types up to
    5 years old. Should I toss the lot or check them all with the ESR meter and
    keep the ones that seem to have "normal" esr compared to a similar factory
    fresh one? I also have a capacitance meter so any that are out of tolerance
    will be tossed anyway.

    (4) I like tantalum caps because they are small and colourful, though I have
    read that they are less tolerant of voltage spikes than aluminium electros.
    I tend to use them instead of small value electros. Any reason why I should
    not?

    PH
     
  2. Phil Allison

    Phil Allison Guest

    "Peter Howard"

    ** You ought to finish the ESR meter and try it out.

    Most of your queries will disappear afterwards.


    ** Most recent manufacture electros ARE low ESR.

    Certainly all the 105C types are.

    The term "low" is relative - ie it means lower than what others are
    currently offering.



    ** So ?


    ** Finish the damn ESR meter.

    Those caps need to be under 2 ohms, ESR.


    ** Plus being silly large.


    ** OK - I can answer that.

    Never let yourself get under somebody's thumb.

    The Rolling Stones did a great song about it.



    ** Finish the damn ESR meter !


    ** If the ESR is OK - so also will be the Faradays.

    Finish the damn ESR meter !!



    ** Bet you just go * ape * over garden gnomes .......



    ** Err - current spikes are their major downfall.

    Some are destroyed by a simple short.


    ** Yep.

    Avoid tants at all costs.




    .......... Phil
     
  3. Shouldn't that read "Avoid Phil's tantrums at all costs."?
     
  4. Parmin

    Parmin Guest

    "Alan Rutlidge" <don'> while reading
    the NewsGroups, found courage and express out opinion in
    err.. tantharums :)
     
  5. Ed -

    Ed - Guest

    add to your list of tests: check leakage after a min or so on a dc
    voltage
    high temp electros are supposed to be longer lasting ie: 105 -v- 85 deg
    C


    : I've just had a tiny triumph by resuscitating a small format ATX PC
    power
    : supply, mainly by replacing all the obviously bulged electros first,
    then
    : every other electro. All with mail order low-esr types. Fortunately,
    the
    : supply was all through hole construction, not SM. Would not have
    bothered
    : except that the small format supplies as found in many mini-tower
    boxes are
    : considerably more costly than a generic standard sized supply.
    : Anyway, I've become interested in electros and esr to the extent of
    buying a
    : Bob Parker MkII ESR meter kit, on special this month at Tricky
    Dicks.Still
    : being assembled.
    :
    : Questions arise.
    : (1) I like to have a few dozen common electros on hand in the parts
    box. All
    : I can get locally is standard esr types. Anything to be said for
    paying a
    : little more and standardizing on low-esr types by mail-order? Is a
    low-esr
    : type necessarily better quality and longer lasting?
    :
    : (2) From studying the RS and Farnell catalogues I notice that they
    have a
    : more limited range of low-esr types. For instance, the smallest 10uf
    type I
    : find is 25VW versus 16VW for "standard" type. What is the experts
    practical
    : experience of selecting working voltage? I Googled the topic and I
    found
    : little in the way of practical advice. For instance, if I want to
    place a
    : filter cap after a 12v 3term regulator, I'd probably choose one of
    : appropriate capacitance and 16VW. What about 25VW? Or 35VW or 63VW?
    : Obviously, I would not use a cap of 300VW as I think I understand that
    : choosing too high a VW won't permit the dielectric film to be
    maintained.
    : What I need is a practical rule-of-thumb.
    :
    : (3) Lots of my parts box electros are small unsused bargain-bag types
    up to
    : 5 years old. Should I toss the lot or check them all with the ESR
    meter and
    : keep the ones that seem to have "normal" esr compared to a similar
    factory
    : fresh one? I also have a capacitance meter so any that are out of
    tolerance
    : will be tossed anyway.
    :
    : (4) I like tantalum caps because they are small and colourful, though
    I have
    : read that they are less tolerant of voltage spikes than aluminium
    electros.
    : I tend to use them instead of small value electros. Any reason why I
    should
    : not?
    :
    : PH
    :
    :
    :
     
  6. Mark Harriss

    Mark Harriss Guest

    I thought his lithiums were charged, not his tantalums
     
  7. Phil Allison

    Phil Allison Guest

    "Chris Jones"

    ** If electro caps are deteriorating and needing replacement - then it is
    *odd on* they are operating in a hot environment. So 105 C types will
    likely last much longer than the 85 C types.

    Also be aware that the ESR of an electro goes DOWN when the cap gets hot -
    by a factor of up to 5 times !!!



    ......... Phil
     
  8. Ross Herbert

    Ross Herbert Guest

    On Sat, 11 Feb 2006 20:25:59 +0000, Chris Jones

    SNIP
    So I should individually form each of those hundreds of electro's I
    have had in stock for 20 years or so? Shouldn't take too long to
    do,should it?

    I agree that it is a good idea that any electro which you are planning
    to use and which has been stored for at least 5 years, should be first
    tested, but you don't go around re-forming all capacitors in storage
    as a matter of course.

    RE-FORMING capacitors which have been in storage is only necessary
    prior to use. Some manufacturers spec sheets recommend reforming is
    not necessary unless they have been in storage for "a minimum 3 years"
    but that is overkill and just playing safe on their part. I have
    tested caps (Matsushita's are excellent) which have not seen a jot of
    DC for more than 20 years and both their ESR and capacitance measured
    nearly as as good as when brand new.
     
  9. Phil Allison

    Phil Allison Guest

    "Chris Jones"

    ** Shame you did not say *that* before.

    Kindly post the revalant info - ie cap maker, ratings, physical size &
    actual ESR readings.

    In many years of checking electros I have NOT come across anything like
    your claim.



    ** You are making this all up as you go along.

    Electros are not operated at such high temps in SMPSs.




    ............ Phil
     
  10. Phil the God and creator of all SMPS's on this would know.
     
  11. Phil Allison

    Phil Allison Guest

    "The Real Andy"



    ** Shame Andy has run out of public toilets to troll.

    Maybe he will stalk the ones at the local primary next.





    ......... Phil
     
  12. You are a sad pathetic fuckwit Allison, when will you come up with
    some new lines? The old ones are becoming a bit tired now.

    Yawn...
     
  13. Phil Allison

    Phil Allison Guest

    "The Real Andy"



    ** Shame Andrew Pearson has run out of public toilets to troll.

    Maybe he will stalk the ones at the local Brisbane primary next.





    ......... Phil
     
  14. Shame Phli Allison the worn out uni reject roadie has run out of
    lines.
     
  15. Phil Allison

    Phil Allison Guest

    "The Real Andy"



    ** I know where you work - you fucking alcoholic idiot.

    How about I speak to your employer and get you dismissed ?






    ......... Phil
     
  16. Dismissed for what? Proving you are an idiot? Pffft. By the way, i
    work for myself now. Try again fool.
     
  17. Net stalking again are you Phyllis Diller Dickwit?

    How about I speak with your neighbours and get you committed to the local
    mental hospital?

    You're a typical example of the mental health system in NSW gone off the
    rails (no pun intended).
    How come you aren't locked up for the safety of the public?

    You're a menace. I couldn't imagine living in the same block of bed-sit
    flats as you. If your behaviour on Usenet is any indication, you'd be the
    typical neighbour from hell.
     
  18. Andy, If there's anyone to blame it's the mental health system in NSW.
    Phil is a typical example of a net-stalking psycho that should have been
    locked up years ago. Instead they put him back into society and gave the
    fool a computer and access to the internet. :-(
     
  19. Phil Allison

    Phil Allison Guest

    "The Real Andy"

    = a Drunk as a Skunk Cunthead



    ** So your long suffering employers at " Jupiters Technology " in
    Brisbane OBVIOUSLY had had a massive, fucking gutful of your
    fuckhead drunk behaviour while at work.

    Not to mention the fact you are a dumb as fucking dog shit
    *electrician puke* pretending to be an " ingineuer ".

    So they finally woke up an gave you the BOOT !!!

    ROTFL

    How time wounds all heels !!!





    ......... Phil
     
  20. So what does that say about you? Self employed Toaster Boi?

    Only a dipstick would employ you (Mr. Charisma) or someone who deliberately
    wanted to run their business as a tax dodge. With you in the picture, any
    venture would be doomed to failure.

    BTW, how do you manage to get by on that less than $50,000 gross turnover
    non-GST reporting "business" of yours? I've done the sums and in
    consideration that you rent that dump of a bed-sit flat which is also your
    place of business you must be surviving on handouts from the Salvos. Either
    that or you're collecting CentreLink benefits and / or falsely declaring
    your income?

    So just how do you get by Phil? I'm sure we'd all be interested to know how
    you do it. :p
     
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