Looking for a Supplier

Discussion in 'General Electronics Chat' started by R!f@@, Sep 18, 2013.

  1. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    Hey guys
    I am trying to get 22uf 35V or 50V Bipolar capacitor
    I tried ebay. What I got was from Italy. The shipping charge was too much.
    Is there any one in here that could do me a favor and sent me. I can pay via paypal if the price is reasonable.
    I need around 20pcs.

    Lemme know if any one is upto it.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Depending on the nature of the signal, two caps back to back in a pinch!.
    Max.
     
  3. Shagas

    Active Member

    May 13, 2013
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  4. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    Just like two caps back to back. But I need the space and the board is already designed. So I need to fit to the space.

    This is what I need. I think. I am trying to make a Gainclone using LM3886. It uses a 22uf BP but it does not state which voltage, so I figured I would go for 35V. May be I need less voltage but I cannot tell. :(

    Any one care to look at the data and tell me what should be the minimum voltage.

    @Shagas.

    I will PM u my address.

    Thank you so much :)
     
    Last edited: Sep 20, 2013
  5. Shagas

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    May 13, 2013
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    Okay no problem , but as I said : Monday is the earliest . I'll check in again on sunday
     
  6. t06afre

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    May 11, 2009
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    Do you have a link or a schematics for your gainclone.
     
  7. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    See link for diagram
    Here...
    Figure 2, C2 is 22uf
     
  8. t06afre

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    May 11, 2009
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    Have you tried with an electrolytic capacitor? In the design example from the datasheet figure 1. They have used a standard electrolyte capacitor not a bipolar electrolytic capacitor in the same place. So I think it is just an drawing error
    Edit: Huh...Looking at the schematic in the datasheet one more time. They have used a bipolar capacitor (ouch). Given the frequency range. A a bipolar electrolytic capacitor will probably do. And they also cost less. Than other choices that can be quite expensive in that value
     
    Last edited: Sep 18, 2013
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    Not sure how it applies to a pair of back to back polar electrolytics, but normally 2 equal capacitors in series equals 1/2 the capacitance.

    Apparently; if you put clamp diodes to prevent reverse charging on both caps, series connection doesn't halve the capacitance.
     
  10. ian field

    Distinguished Member

    Oct 27, 2012
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    For 22uF; you might want to check out multilayer ceramic chip - some manufacturers also do resin dipped leaded versions.

    They're smaller than electrolytics (especially non-polar ones) and have very low leakage and ESR.
     
  11. R!f@@

    Thread Starter AAC Fanatic!

    Apr 2, 2009
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    I prefer bipolar.

    Any one figured out the exact capacitor voltage tht would be needed minimum.
    Or is 35V OK.

    Please lemme know the price first.
     
  12. t06afre

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    The question is, do you need that cap at all?
     
  13. R!f@@

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    Very funny t0. :rolleyes:
    Of course I need the capacitor. In fact I need another.

    I have the speaker protector tht uses a BP.
    So I decided to change the voltage and be safe.

    Here is the updated list.

    1. 22uf 50V BP - 50pc
    2. 10uf 50V BP - 50pc

    This is final on bipolar caps. All others I can get.
    Where is Shagas by the way. :confused:
     
  14. t06afre

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    I guess the most important role of that cap is to ensure a gain of 1 for DC. But if you have a DC block in the stages before. And at the same time include a speaker protector. I would say it could certainly be discussed how important that cap are
     
  15. R!f@@

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    U are telling me tht it is not needed .
     
  16. t06afre

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    It has something to say for the amplifier frequency response. It is not needed for the amp to work strictly speaking
     
    Last edited: Sep 19, 2013
  17. Shagas

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    May 13, 2013
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    Sorry , I had some work to do .
    I've start lectures on monday morning so I can run down to the store then and send them in the afternoon.
    Pm me how many you need and your adress of course :)
    They cost 6.30 Kc each which is 0.33 USD
     
  18. R!f@@

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    U are confusing me.
    I am using a active crossover prior to amp from 100Hz to 20Khz.
    The L+R channel uses two amps per channel (LM3886) .
    One for high and one for low/mid.

    High is HP filter from 3Khz and above.
    Low/Mid is band pass from 100Hz to 3Khz.

    Plus a speaker switch on and DC protector circuitry.

    Ur info is enlighting. :) I will try it. But for future projects I might need the capacitor.

    Thanks t0
     
    Last edited: Sep 20, 2013
  19. t06afre

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    You can always put some space for it on the board. And just strap it if not needed. If you have a second order high/band pass filter (100/3KHz) before the stage. I think you will not need that cap. At least not hear any difference with or without it.
     
  20. Alec_t

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    Sep 17, 2013
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    C2 is subjected to only a few mV swing. A 6.3V ceramic should suffice.
     
    Last edited: Sep 20, 2013
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