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    #1

    Did anyone else notice this before???

    It has long been known that those silly 4700uF 10mm Fuhjyyus are bogus anyway. But I just noticed something. Looking at the Nichicon HM table...

    6.3V
    1500uF - 10mm x 12.5mm
    2200uF - 10mm x 16mm
    3300uF - 10mm x 20mm
    (smallest sizes for each value)

    So I figured...
    3900uF - 10mm x 25mm
    4700uF - 10mm x 30mm

    So it appears that it actually is possible to make 4700uF 6.3V caps in 10mm. (Yes, I know the Fuhjyyus mentioned are 10V, but surely it's not beyond Fuhjyyu to take 6.3V caps and label them as 10V...)

    Okay, so I have no idea how they managed to make those 3300uF 16V 10mm SamXon RS. But that's another mystery for another day.
    Tags: None
    #2
    Re: Did anyone else notice this before???

    Surely if you were able to pull some unused Fuhjyyus you could test whether they were 10V by applying say 9.5V through them. I don't think the voltage rating would be bogus.

    Comment

      #3
      Re: Did anyone else notice this before???

      So it appears that it actually is possible to make 4700uF 6.3V caps in 10mm.
      If you go by the logic that a reduction in width can always be compensated for by an increase in height - but we don't know that. It's been implied before, but you'd have to ask an actual engineer.

      Teapo also made "4700uf" 10mm caps that were really 3300uF caps (These are Teapo "SC" series, and the dimensions are 10x30 FYI). I've still got two of them from my SP450 re-cap, and they're not bulged. I'd like to test them someday if I ever get a meter.
      "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

      -Leonid Brezhnev (On the Yom Kippur War)

      Comment

        #4
        Re: Did anyone else notice this before???

        I don't think the voltage rating would be bogus.
        ...or would it??? You know what Fuhjyyu are like.

        I'm also willing to bet that the 3300uF 16V 10mm TMs are actually 2200uF.

        And there's also a 2200uF 6.3V 8mm TM specified. Maybe that's actually a 1500uF.

        Comment

          #5
          Re: Did anyone else notice this before???

          Originally posted by Shocker View Post
          ...or would it??? You know what Fuhjyyu are like.

          I'm also willing to bet that the 3300uF 16V 10mm TMs are actually 2200uF.

          And there's also a 2200uF 6.3V 8mm TM specified. Maybe that's actually a 1500uF.
          Lets not get talking about '470uF' 200v caps now
          Muh-soggy-knee

          Comment

            #6
            Re: Did anyone else notice this before???

            Nichicon and Panny also make 2200uF 6.3v caps in 8mm diameter
            I love putting bad caps and flat batteries in fire and watching them explode!!

            No wonder it doesn't work! You installed the jumper wires backwards

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            Comment

              #7
              Re: Did anyone else notice this before???

              I know, but Fuhjyyu TM isn't even close to HM and FJ.

              Comment

                #8
                Re: Did anyone else notice this before???

                Capacitance is directly proportional to the surface area of the plates, which given the same thicknesses/number of windings/same diameter is also directly proportional to the height of the cylinder.

                The vertical linear density for the 10mm 6.3V caps you've listed are:
                1500uF - 120uF/mm
                2200uF - 137.5uF/mm
                3300uF - 165uF/mm

                Using the 120uF/mm number to be conservative results in a 40mm high cap for 4700uF, while 165uF/mm results in 28.5mm.

                For the 10V HMs...
                1000uF 10 x 12.5 - 80uF/mm
                1500uF 10 x 16 - 93.75uF/mm
                1800uF 10 x 20 - 90uF/mm
                2200uF 10 x 25 - 88uF/mm
                ...resulting in a 10V 4700uF 10mm cap being between 58.75mm and 50.13mm high.

                Those 10x30 10V SC even at 3300uF would be 110uF/mm, which is a bit on the high side. 2700uF - 90uF/mm - seems much more reasonable.

                Comment

                  #9
                  Re: Did anyone else notice this before???

                  b700029 - Fantastic... Kudos to you.
                  "We have offered them (the Arabs) a sensible way for so many years. But no, they wanted to fight. Fine! We gave them technology, the latest, the kind even Vietnam didn't have. They had double superiority in tanks and aircraft, triple in artillery, and in air defense and anti-tank weapons they had absolute supremacy. And what? Once again they were beaten. Once again they scrammed [sic]. Once again they screamed for us to come save them. Sadat woke me up in the middle of the night twice over the phone, 'Save me!' He demanded to send Soviet troops, and immediately! No! We are not going to fight for them."

                  -Leonid Brezhnev (On the Yom Kippur War)

                  Comment

                    #10
                    Re: Did anyone else notice this before???

                    http://en.wikipedia.org/wiki/Capacitance

                    Capacitance goes up as the plates get closer but the voltage goes down. If you can improve the dielectric to resist more voltage you can make a higher uF cap in the same size package.

                    A DUOYI DY294 will tell you if they are cheating on voltage.
                    sig files are for morons

                    Comment

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