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Discussion in 'Electronic Design' started by [email protected], May 2, 2013.

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  1. Guest

  2. Guest

  3. Tim Williams

    Tim Williams Guest

    Yuck. Graph straight off the ceramic's D-E curve (compare: B-H curve),
    the derivative that is. Only thing they don't show is hysteresis, which
    is bound to be comparable.

    They need to start putting some air gap into those suckers!


    Deep Friar: a very philosophical monk.

    Yep, it's a matter of high dielectric constant materials. Standard
    for Z5U[*], unexpected for X7R-types. The subject carpacitor(tm) was
    X5R, but looks more like Z5U than X7R.

    I'm looking at a few mfrs' offerings to see if anyone's dielectric is

  4. Well as you know the X5/7 spec is just the tempco. Anything goes with
    the V spec I guess. buyer beware and all that....

    Thanks for the 'heads up'

    George H.
  5. Robert Baer

    Robert Baer Guest

    Now when i tried to look at the PDF, my Adobe 9.0 wanted an "upgrade"
    by adding Japanese font.
    I said no, and got essentially blank pages.
    So, i retried, said yes and everything was there.
    Drawings, graphs, etc have NOTHING to do with Japanese, and only
    English was used.
  6. I've got this audio amp that runs off 15 volts.
    But I've told people you can stick upto 40V into it.
    (as long as it doesn't over heat.)
    The IC's are good to 60V (I think, LM675?) but I've only got 50V tants
    as bypass C's. I should do a mod to 100V tants. Someone will want
    more V.

    George H.
  7. Guest

    Yup, the X/?/? notation mostly tells you Class I, II, or III
    dielectric. I thought perhaps different mfrs would have different
    secret sauces. If so, I haven't found it yet.

    Pg. 9, figure 4 of the Yageo link is frightening. A 50V Y5V has 90% C-
    loss at 20WVDC.

    Getting a MUCH-higher woltage-rated part helps preserve capacitance a
    smidgen. Using a physically larger part helps a lot.
    Sure. I thought Joerg might be interested for his transducer-cap
    selection. He'd want high capacitance, low-voltage, and small
    package. That should maximize everything we normally hate.
  8. Guest

    CAPACITANCE LOSS vs. DC VOLTAGE, 0603, 4.7uF, mfr=TDK

    DC-Bias/V X5R, 35V JB, 6.3V X5R, 10V
    --------- -------- -------- --------
    0V 0.0% 0.0% 0.0%
    1.25 -3.7 -4.4 -16.2
    2 -10.2 -11.6 -38.2
    2.5 -16.6 -23.0
    3.15 -24.5 -31.5 -58.8
    4 -35.4 -41.4 -68.0
    5 -45.9 -54.0 -75.6
    6.3 -56.9 -81.8
    8 -67.5 -86.5
    10 -74.8 -89.6
    12.5 -80.9
    16 -86.0
    25 -91.6
    35 -94.2

    Just FYI, here's a comparison of some TDK parts in various

    These data are from TDK's Component Characteristic Viewer,
  9. Robert Baer

    Robert Baer Guest

  10. Guest

    No, actually, John suggested a parametric oscillator and several other

  11. Bill Martin

    Bill Martin Guest

    Or if you really want to annoy your neighbors, you could sweep a
    resonant load across your powerline...
  12. Guest

    Not just baseband -- scouting Digi-Key, you can get Y5V down to 10nF.
    There's surely something this would be really good for, but in ten
    years I haven't thought of it yet. (Plenty of ideas for VCOs,
    resonant tanks, etc, but no killer apps.)

    It might be handy for tuning the tanks of one of these resonant
    wireless energy schemes--crapacitors + inductors makes a handy
    tunable, low-loss energy storage.
  13. Jeroen

    Jeroen Guest

    Interesting gadget. Just about what I asked for some time ago.

    Jeroen Belleman
  14. Guest

    Yes, very impressively bad. Looks like fodder for a green grant--it
    could be sooo much better with just a little invest-mint(tm).
  15. Jeroen

    Jeroen Guest

    No one said it was useful for energy conversion.

    It's interesting, because normally non-linearity will only produce
    harmonics, multiples, of the input frequency. This one also produces
    sub-harmonics, at half the frequency in this case, just using a
    single passive non-linear element.

    There is an optical domain equivalent gadget that fascinates the
    quantum theory crowd since quite some time already. It also has
    an impressively poor conversion efficiency: A BBO crystal.
    I've been looking for a simple passive circuit with similar
    behaviour. This appears to qualify.

    Jeroen Belleman
  16. Guest

    Which is exactly why it's ripe for green (or green for ripening), so
    to speak.
    Replacing John's schottky with a Y5V capacitor gives the same results,
    for similar reasons. You can try it with a varactor in LTSpice. I
    just made a /3.

    The resonant energy reference wasn't entirely frivolous: this circuit
    points out pretty well the exact challenges of wireless resonant
    transfer in pragmatic detail. With ideal parts, the weak transfer-
    coupling isn't a problem since all the un-transferred energy just
    sloshes around un-wasted in a perfect tank circuit--there aren't any
    ohmic losses. In reality, there are ohmic losses, and that kills it.
    The world of optics and atoms is a different matter entirely; there
    you have all sorts of nearly ideal components.
  17. Robert Baer

    Robert Baer Guest

    You forgot to mention that they could be used in an artificial
    transmission line to speed up the leading edge of a pulse ..
  18. Guest

    Sure. I know John--he's not the monster you think. The FLIR stuff in
    the SMD heatsink thread would be closely-guarded competitive info at
    other places, not cheerfully shared (with photos) on the web.
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