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SGI multiplayer was Re: [midatlanticretro] More bustin caps!

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  • 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 1 of 18 , Feb 27 1:00 PM
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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 2 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 3 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 4 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 5 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 6 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 7 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 8 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 9 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 10 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 11 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 12 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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