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Re: [midatlanticretro] More bustin caps!

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  • Mr Ian Primus
    ... Yeah, tantalum capacitors do that from time to time. They re almost always simple filters, so in MOST circuits, you can just clip them out and it ll still
    Message 1 of 18 , Feb 27, 2012
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      --- On Mon, 2/27/12, Christian Liendo <christian_liendo@...> wrote:

      > Needless to say, we blew a capacitor and the unit caught on
      > fire.

      Yeah, tantalum capacitors do that from time to time. They're almost always simple filters, so in MOST circuits, you can just clip them out and it'll still work. It's pretty toasted so you can't get a value off it, but check nearby tantalums of a similar size, if there are any. Normally you'll be fine with 10uf.

      -Ian
    • B Degnan
      ... Herb Johnson had at one time a large number of SGI systems for sale/parts. I am copying him, if he has any comments of what he may have available for
      Message 2 of 18 , Feb 27, 2012
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        At 09:36 AM 2/27/2012, you wrote:
        >--- On Mon, 2/27/12, Christian Liendo <christian_liendo@...> wrote:
        >
        > > Needless to say, we blew a capacitor and the unit caught on
        > > fire.
        >
        >Yeah, tantalum capacitors do that from time to time. They're almost
        >always simple filters, so in MOST circuits, you can just clip them
        >out and it'll still work. It's pretty toasted so you can't get a
        >value off it, but check nearby tantalums of a similar size, if there
        >are any. Normally you'll be fine with 10uf.
        >
        >-Ian

        Herb Johnson had at one time a large number of SGI systems for
        sale/parts. I am copying him, if he has any comments of what he may
        have available for sale.

        Bill
      • Neil Cherry
        ... Agreed, 10 uF is usually acceptable for a cap of that size. Just be careful of the polarity or you ll be bustin more caps. -- Linux Home Automation
        Message 3 of 18 , Feb 27, 2012
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          On 02/27/2012 09:36 AM, Mr Ian Primus wrote:
          >
          >
          > --- On Mon, 2/27/12, Christian Liendo <christian_liendo@...
          > <mailto:christian_liendo%40yahoo.com>> wrote:
          >
          >> Needless to say, we blew a capacitor and the unit caught on
          >> fire.
          >
          > Yeah, tantalum capacitors do that from time to time. They're almost always simple filters,
          > so in MOST circuits, you can just clip them out and it'll still work. It's pretty toasted
          > so you can't get a value off it, but check nearby tantalums of a similar size, if there
          > are any. Normally you'll be fine with 10uf.

          Agreed, 10 uF is usually acceptable for a cap of that size. Just be careful
          of the polarity or you'll be bustin more caps.

          --
          Linux Home Automation Neil Cherry ncherry@...
          http://www.linuxha.com/ Main site
          http://linuxha.blogspot.com/ My HA Blog
          Author of: Linux Smart Homes For Dummies
        • Christian Liendo
          The 4D/20 was the oldest one we had and I wanted to show it off. Right now we have three Indys, but are trying to get working 2GB SCSI 1 drives that work on
          Message 4 of 18 , Feb 27, 2012
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            The 4D/20 was the oldest one we had and I wanted to show it off.


            Right now we have three Indys, but are trying to get working 2GB SCSI 1 drives that work on these.
            We went through 2 Barracudas and a Seagate, I have to go through a storage space of mine to see if I have additional drives.


            I have an Octane that works great.

            I also am bugging a friend of mine for marketing material to show off at the event.

            I kinda want to show SGIs and how back then there was 3D multiplayer networked flight sims..
            They just cost $60000 a machine. Thats all.


            ________________________________
            From: B Degnan <billdeg@...>


            Herb Johnson had at one time a large  number of SGI systems for
            sale/parts.  I am copying him, if he has any comments of what he may
            have available for sale.
          • Alexey Toptygin
            ... I have a pair of Iris Indigo Elans, but I m not sure if they work and I don t have any software for them. This is a really cool idea, and I will try to get
            Message 5 of 18 , Feb 27, 2012
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              On Mon, 27 Feb 2012, Christian Liendo wrote:

              > We have one SGI working and am working on getting a second..
              >
              > Anyone else own a SGI and would like to bring to VCF and play a
              > networked version of Dogfight? Maybe BZFLAG?

              I have a pair of Iris Indigo Elans, but I'm not sure if they work and I
              don't have any software for them. This is a really cool idea, and I will
              try to get at least one of them working to bring to VCF.

              Alexey
            • Christian Liendo
              That would be cool I am trying to convince someone to bring theirs as well, but he would be coming in from PA. The last time I did something like this was in
              Message 6 of 18 , Feb 27, 2012
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                That would be cool

                I am trying to convince someone to bring theirs as well, but he would be coming in from PA.

                The last time I did something like this was in 1996 when I was at SGI doing training on the new Onyx2s..
                 
                ________________________________

                From: Alexey Toptygin <alexeyt@...>
                > I have a pair of Iris Indigo Elans, but I'm not sure if they work and I don't have any software for them. This is a really cool idea, and I will
                try to get at least one of them working to bring to VCF.
              • Dave McGuire
                ... [sorry to reply to such an old thread; I had saved this away to send a reply but then forgot about it] In the case of switching regulators, this can go
                Message 7 of 18 , Mar 13, 2012
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                  On 02/27/2012 09:36 AM, Mr Ian Primus wrote:
                  > Yeah, tantalum capacitors do that from time to time. They're almost
                  > always simple filters, so in MOST circuits, you can just clip them
                  > out and it'll still work. It's pretty toasted so you can't get a
                  > value off it, but check nearby tantalums of a similar size, if there
                  > are any. Normally you'll be fine with 10uf.

                  [sorry to reply to such an old thread; I had saved this away to send
                  a reply but then forgot about it]

                  In the case of switching regulators, this can go very bad, very
                  quickly. Capacitors used on the inputs and outputs of switching
                  regulators, almost always tantalums, are an integral part of the
                  regulator circuit and can't be treated as expendable. In this role,
                  they are specced for very low ESR, and are as such pretty expensive.

                  If you seen one physically or electrically near a big inductor, or a
                  Schottky diode, be very careful about replacing it, and whatever you do,
                  don't attempt to power up the circuit without it. The result will
                  likely be a big fat sawtooth wave being applied to your power rail,
                  pissing off pretty much anything it's connected to.

                  -Dave

                  --
                  Dave McGuire, AK4HZ
                  New Kensington, PA
                • Dan Roganti
                  ... This is true And it also makes a difference whether you re dealing with Logic or audio circuits - eg. decoupling versus signal path (Tantalums cause more
                  Message 8 of 18 , Mar 13, 2012
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                    On Tue, Mar 13, 2012 at 7:42 PM, Dave McGuire <Mcguire@...> wrote:
                    On 02/27/2012 09:36 AM, Mr Ian Primus wrote:
                    > Yeah, tantalum capacitors do that from time to time. They're almost
                    > always simple filters, so in MOST circuits, you can just clip them
                    > out and it'll still work. It's pretty toasted so you can't get a
                    > value off it, but check nearby tantalums of a similar size, if there
                    > are any. Normally you'll be fine with 10uf.

                      [sorry to reply to such an old thread; I had saved this away to send
                    a reply but then forgot about it]

                      In the case of switching regulators, this can go very bad, very
                    quickly.  Capacitors used on the inputs and outputs of switching
                    regulators, almost always tantalums, are an integral part of the
                    regulator circuit and can't be treated as expendable.  In this role,
                    they are specced for very low ESR, and are as such pretty expensive.

                    This is true
                    And it also makes a difference whether you're dealing with Logic or audio circuits  - eg. decoupling versus signal path (Tantalums cause more distortion) and frequency (ie. reactance)
                    But.....Tantalums suck now and they always sucked 35yrs ago - it was a necessary evil :)
                    It's become a lazy alternative - oh just stick a Tantalum in there and call it quits - using Tantalums is just an easy way out. They blowup because they always had and still have a weakness. They blow up when they short out since they can't handle a small amount of surge since they have a thin dielectric. These days, alternatives  - even better spec'd - have been around for quite some time now, for over a decade - and just as cheap. Besides tantalum mining supplles have been dwindling, that's why manufactures are using alternatives.
                    =Dan

                  • Dave McGuire
                    ... I think that, while your points are absolutely correct of course, you re being a bit harsh. Sure, they blow up when you reverse-polarity them, but then so
                    Message 9 of 18 , Mar 13, 2012
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                      On 03/13/2012 10:26 PM, Dan Roganti wrote:
                      > But.....Tantalums suck now and they always sucked 35yrs ago - it was a
                      > necessary evil :)
                      > It's become a lazy alternative - oh just stick a Tantalum in there and
                      > call it quits - using Tantalums is just an easy way out. They blowup
                      > because they always had and still have a weakness. They blow up when
                      > they short out since they can't handle a small amount of surge since
                      > they have a thin dielectric.

                      I think that, while your points are absolutely correct of course,
                      you're being a bit harsh. Sure, they blow up when you reverse-polarity
                      them, but then so do lots of other components. And yes, they die when
                      they start to hit thirty years old. Well...For my work stuff, I doubt
                      there will be many S25 boards in service thirty years from now, and they
                      certainly won't be collectors' items...so I'm not too worried about
                      that. (for others here: the S25 is the design I'm working on at work
                      right now)

                      It's not necessarily any easier to type one part number into the BOM
                      rather than another. I use tantalums in my new design because they work
                      well and are fine for my application.

                      Further, they're nowhere near as bad now as they used to be. It's
                      not like tantalum technology has been standing still while the rest of
                      capacitor technology has been speeding forward, y'know!

                      > These days, alternatives - even better
                      > spec'd - have been around for quite some time now, for over a decade -
                      > and just as cheap.

                      What's your favorite these days, for high density and low ESR?
                      Aluminum maybe? More to the point...I'm putting an LTC1474 switching
                      regulator in a schematic tonight, and am about to spec tantalums for the
                      oh-so-critical input and output capacitors. They need to be rated for
                      high surge voltage and very low ESR, and the ones I have in mind meet
                      the spec nicely. What would you use instead? I'll defer finishing this
                      part of the schematic until later...might use something non-tantalum if
                      you can point me to a manufacturer and series.

                      > Besides tantalum mining supplles have been dwindling,
                      > that's why manufactures are using alternatives.

                      Very true. And sucky. :-(

                      -Dave

                      --
                      Dave McGuire, AK4HZ
                      New Kensington, PA
                    • Dan Roganti
                      ... No, they blow up when they are mounted correctly. That s the whole point which I mentioned about them being inferior - they have been constructed with a
                      Message 10 of 18 , Mar 13, 2012
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                        On Tue, Mar 13, 2012 at 11:12 PM, Dave McGuire <Mcguire@...> wrote:
                        On 03/13/2012 10:26 PM, Dan Roganti wrote:
                        > But.....Tantalums suck now and they always sucked 35yrs ago - it was a
                        > necessary evil :)
                        > It's become a lazy alternative - oh just stick a Tantalum in there and
                        > call it quits - using Tantalums is just an easy way out. They blowup
                        > because they always had and still have a weakness. They blow up when
                        > they short out since they can't handle a small amount of surge since
                        > they have a thin dielectric.

                          I think that, while your points are absolutely correct of course,
                        you're being a bit harsh.  Sure, they blow up when you reverse-polarity
                        them, but then so do lots of other components.  

                        No, they blow up when they are mounted correctly.
                        That's the whole point which I mentioned about them being inferior - they have been constructed with a weaker dielectric

                         

                          Further, they're nowhere near as bad now as they used to be.  It's
                        not like tantalum technology has been standing still while the rest of
                        capacitor technology has been speeding forward, y'know!


                        just as with alternatives

                         

                        > These days, alternatives  - even better
                        > spec'd - have been around for quite some time now, for over a decade -
                        > and just as cheap.

                          What's your favorite these days, for high density and low ESR?
                         

                         LowESR.com - Resource for Low ESR Capacitors - and high voltage and reactance

                        ;)
                        =Dan


                         _  ____
                        / \__/  
                        Scotty, We Need More Power !!
                        \_/ _\__ Aye, Cap'n, but me Tantalums keep blowing !!

                      • Dave McGuire
                        ... I ve never once seen a tantalum blow up just because when it hadn t been subjected to physical, thermal, or electrical stresses beyond its
                        Message 11 of 18 , Mar 13, 2012
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                          On 03/13/2012 11:50 PM, Dan Roganti wrote:
                          > > But.....Tantalums suck now and they always sucked 35yrs ago - it
                          > was a
                          > > necessary evil :)
                          > > It's become a lazy alternative - oh just stick a Tantalum in
                          > there and
                          > > call it quits - using Tantalums is just an easy way out. They blowup
                          > > because they always had and still have a weakness. They blow up when
                          > > they short out since they can't handle a small amount of surge since
                          > > they have a thin dielectric.
                          >
                          > I think that, while your points are absolutely correct of course,
                          > you're being a bit harsh. Sure, they blow up when you reverse-polarity
                          > them, but then so do lots of other components.
                          >
                          >
                          > No, they blow up when they are mounted correctly.
                          > That's the whole point which I mentioned about them being inferior -
                          > they have been constructed with a weaker dielectric

                          I've never once seen a tantalum blow up "just because" when it hadn't
                          been subjected to physical, thermal, or electrical stresses beyond its
                          specifications. (that said, though, the world is full of companies which
                          have "cost engineering" departments, who cheapen the BOM and give us
                          Wal*Mart-quality trash)

                          Further, all of them that I've replaced over the years, and I concede
                          that it has been a shitload, all died due to old age. For a classic
                          computer, that's terrible, and for test equipment, it's annoying. But
                          for my stuff, in the context of industrial controls where there will
                          almost definitely never be a "retro" fetish, I'm quite happy with them.

                          The purist in me, however, certainly wouldn't mind finding (and
                          becoming accustomed to using) a better alternative.

                          > > These days, alternatives - even better
                          > > spec'd - have been around for quite some time now, for over a
                          > decade -
                          > > and just as cheap.
                          >
                          > What's your favorite these days, for high density and low ESR?
                          >
                          >
                          > LowESR.com - Resource for Low ESR Capacitors <http://www.low-esr.com/> -
                          > and high voltage and reactance

                          Yes, I know there are lots of industry resources. I was wondering if
                          you had a specific family in mind.

                          Those aluminum/polymer electrolyte capacitors sure do look
                          interesting. And those other aluminum caps, the cans...a hybrid of
                          solid and liquid polymer electrolyte? That's neat. I'll be requesting
                          samples of those.

                          -Dave

                          --
                          Dave McGuire, AK4HZ
                          New Kensington, PA
                        • Jeffrey Brace
                          ... You were supposed to wait until you got it to VCF before it caught fire ! Then you could get the first to smoke award ! ;)
                          Message 12 of 18 , Mar 13, 2012
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                            > So Brian and I tried to get his Personal Iris 4D running for VCF East

                            > Needless to say, we blew a capacitor and the unit caught on fire.

                            You were supposed to wait until you got it to VCF before it caught fire !
                            Then you could get the first to smoke award ! ;)
                          • Dan Roganti
                            ... Is it cheating then if you stick another Tantalum cap in there to make it smoke again ;) =Dan
                            Message 13 of 18 , Mar 13, 2012
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                              On Mar 14, 2012 12:52 AM, "Jeffrey Brace" <ark72axow@...> wrote:
                              >
                              > > So Brian and I tried to get his Personal Iris 4D running for VCF East
                              >
                              > > Needless to say, we blew a capacitor and the unit caught on fire.
                              >
                              > You were supposed to wait until you got it to VCF before it caught fire !
                              > Then you could get the first to I smoke award ! ;)

                              Is it cheating then if you stick another Tantalum cap in there to make it smoke again ;)

                              =Dan

                            • Dan Roganti
                              ... Aww, isn t he special - that s what you don t get to see sitting behind a console terminal ;) That s why there are Test reports available for reading. The
                              Message 14 of 18 , Mar 14, 2012
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                                On Wed, Mar 14, 2012 at 12:24 AM, Dave McGuire <Mcguire@...> wrote:
                                On 03/13/2012 11:50 PM, Dan Roganti wrote:
                                >
                                >        I think that, while your points are absolutely correct of course,
                                >     you're being a bit harsh.  Sure, they blow up when you reverse-polarity
                                >     them, but then so do lots of other components.
                                >
                                >
                                > No, they blow up when they are mounted correctly.
                                > That's the whole point which I mentioned about them being inferior -
                                > they have been constructed with a weaker dielectric

                                  I've never once seen a tantalum blow up "just because" when it hadn't
                                been subjected to physical, thermal, or electrical stresses beyond its
                                specifications.
                                 
                                Aww, isn't he special - that's what you don't get to see sitting behind a console terminal ;)
                                That's why there are Test reports available for reading.
                                The R13 boards that I fixed had those problems - we had thought they were installed backwards but they weren't - I explained this already to Mike -  and that's not even an extreme case.
                                It's not normal to have exploding devices that cause fire and burn a hole your PCB for typical failures.
                                Extreme cases, such as lightening strikes are not care, because the whole circuit is going to fry.
                                The problem is that Tantalums are less resilent than others - but they do have polymer tantalums now which ar better now - but the engineering community is steering away from these.
                                 
                                 
                                >      > These days, alternatives  - even better
                                >      > spec'd - have been around for quite some time now, for over a
                                >     decade -
                                >      > and just as cheap.
                                >
                                >        What's your favorite these days, for high density and low ESR?
                                >
                                >
                                > LowESR.com - Resource for Low ESR Capacitors <http://www.low-esr.com/> -
                                > and high voltage and reactance

                                  Yes, I know there are lots of industry resources.  I was wondering if
                                you had a specific family in mind.

                                  Those aluminum/polymer electrolyte capacitors sure do look
                                interesting.  
                                 
                                yes, I mentioend that to you a while back, about time you listen ;)
                                 
                                =Dan

                                 
                              • Dave McGuire
                                ... Ahem. ... I cede to the fact that you ve been in the repair business for a very long time, but don t make the mistake of assuming that us designers
                                Message 15 of 18 , Mar 14, 2012
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                                  On 03/14/2012 11:19 AM, Dan Roganti wrote:
                                  > > I think that, while your points are absolutely correct of
                                  > course,
                                  > > you're being a bit harsh. Sure, they blow up when you
                                  > reverse-polarity
                                  > > them, but then so do lots of other components.
                                  > >
                                  > >
                                  > > No, they blow up when they are mounted correctly.
                                  > > That's the whole point which I mentioned about them being inferior -
                                  > > they have been constructed with a weaker dielectric
                                  >
                                  > I've never once seen a tantalum blow up "just because" when it hadn't
                                  > been subjected to physical, thermal, or electrical stresses beyond its
                                  > specifications.
                                  >
                                  > Aww, isn't he special -

                                  Ahem.

                                  > that's what you don't get to see sitting behind
                                  > a console terminal ;)

                                  I cede to the fact that you've been in the repair business for a very
                                  long time, but don't make the mistake of assuming that us designers
                                  (particularly my kind of designer) have no contact with the outside
                                  world. Indeed, how many boards have I built, and goodies have I
                                  repaired, in the past few months? ;)

                                  > That's why there are Test reports available for reading.
                                  > The R13 boards that I fixed had those problems - we had thought they
                                  > were installed backwards but they weren't - I explained this already to
                                  > Mike - and that's not even an extreme case.

                                  Waitaminute...When we looked at the remains of some of those, I
                                  recall specifically that we looked at the bevels. They weren't reversed?

                                  Further, this was in the R13...I don't recall if it was the 24V-side
                                  capacitors or the 5V-side capacitors that had blown up, but the 24V side
                                  regularly sees spikes to 40-50V and the 5V side (since that 5V bus got
                                  run all around the chassis with no filtering) was seeing spikes at 20+V.
                                  Looking at the schematics I see the former were rated at 35V, and the
                                  latter at 10V.

                                  > The problem is that Tantalums are less resilent than others - but they
                                  > do have polymer tantalums now which ar better now - but the engineering
                                  > community is steering away from these.

                                  Yes, their prices are going up.

                                  > > LowESR.com - Resource for Low ESR Capacitors
                                  > <http://www.low-esr.com/> -
                                  > > and high voltage and reactance
                                  >
                                  > Yes, I know there are lots of industry resources. I was wondering if
                                  > you had a specific family in mind.
                                  >
                                  > Those aluminum/polymer electrolyte capacitors sure do look
                                  > interesting.
                                  >
                                  > yes, I mentioend that to you a while back, about time you listen ;)

                                  I ALWAYS listen to you, my friend...my memory just sucks. Do you
                                  have any of those capacitors around? If not, I'll order some and stick
                                  them in an LTC1474 test circuit. (that's my "go-to" regulator nowadays
                                  for 5V and 3.3V medium-current stuff)

                                  -Dave

                                  --
                                  Dave McGuire, AK4HZ
                                  New Kensington, PA
                                • Dan Roganti
                                  ... geez, how do you like that, dissing us ol folk. As if we never designed anything. How do you like that. Can t get no respect these days, man I tell ya ;)
                                  Message 16 of 18 , Mar 14, 2012
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                                    On Wed, Mar 14, 2012 at 9:04 PM, Dave McGuire <Mcguire@...> wrote:

                                      I cede to the fact that you've been in the repair business for a very
                                    long time, but don't make the mistake of assuming that us designers


                                    geez, how do you like that, dissing us ol' folk. As if we never designed anything. How do you like that. Can't get no respect these days, man I tell ya ;)
                                     

                                    (particularly my kind of designer) have no contact with the outside
                                    world.  Indeed, how many boards have I built, and goodies have I
                                    repaired, in the past few months? ;)

                                    how high should I pull up my pants now :D

                                    =Dan


                                  • Dave McGuire
                                    ... I never suggested that, or even anything close to it. I only suggested that you re not the only person here to have seen the inside of electronic
                                    Message 17 of 18 , Mar 14, 2012
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                                      On 03/14/2012 09:59 PM, Dan Roganti wrote:
                                      > I cede to the fact that you've been in the repair business for a very
                                      > long time, but don't make the mistake of assuming that us designers
                                      >
                                      > geez, how do you like that, dissing us ol' folk. As if we never designed
                                      > anything. How do you like that. Can't get no respect these days, man I
                                      > tell ya ;)

                                      I never suggested that, or even anything close to it. I only
                                      suggested that you're not the only person here to have seen the inside
                                      of electronic equipment before, and my opinions of tantalum capacitors,
                                      while low, are nowhere near as low as yours. That is all.

                                      > (particularly my kind of designer) have no contact with the outside
                                      > world. Indeed, how many boards have I built, and goodies have I
                                      > repaired, in the past few months? ;)
                                      >
                                      >
                                      > how high should I pull up my pants now :D

                                      The party's just gettin' started! ;)

                                      -Dave

                                      --
                                      Dave McGuire, AK4HZ
                                      New Kensington, PA
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