Parallel capacitors

Discussion in 'The Workbench' started by JM5010, Aug 10, 2020.

  1. JM5010

    JM5010 Active Member

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    I want to put a 22uf 450V and a 22uf 50V cap in parallel to get 44uf.

    Would this blow anything up? Or lower how much voltage the caps can handle? Want to see how 44uf filtering sounds in my amp’s preamp nodes before i buy anything.
     
  2. South Park

    South Park Well-Known Member

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    Are We talking filter caps if so scrap the The 50 volt cap . Can you explain more
     
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  3. junk notes

    junk notes Well-Known Member

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    The higher voltage will handle the lower voltages, so you really have 2 x 22μF 50V. That is the total voltage capacity without issue. I am not sure about the other technical info, sorry. There should be knowledgeable members here to help.
     
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  4. JM5010

    JM5010 Active Member

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    Filter caps, yes.

    Here’s what i’m trying to do:
     

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  5. JohnH

    JohnH Well-Known Member

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    Both caps will see the full voltage. If several hundred volts hits a 50V cap it would be safer to be in a different room.
     
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  6. South Park

    South Park Well-Known Member

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    I don’t think filter caps ad like other stuff does . all you are doing is filter a filter you are not adding anything like stored power . The fifty volt one might work if you don’t put much load on it . Do some online research hope that helps
     
  7. South Park

    South Park Well-Known Member

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    I did some research they do add so can Get the number you want . Just get the high voltage ones if using for tubes .
     
  8. mickeydg5

    mickeydg5 Well-Known Member

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    No.
    If doing so both should be 450V.
     
  9. william vogel

    william vogel Active Member

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    Adding a capacitor in parallel sums the capacitance, meaning 2x 22uF = 44uF or a 22uF + a 100uF =122uF. The voltage rating of the capacitor doesn’t change/ improve or degrade. If the circuit maximum voltage is 400 volts or whatever it actually is, the capacitor MUST be rated higher than that voltage and it’s helpful for capacitor life to install a capacitor rated for 20% greater voltage or so. Being that there’s a 22uF @ 450 volts already installed, I would put another 22uF @ 450 volts or 500 volts rating. The 50 volt cap will fail and possibly short circuit or explode and it’s not worth adding it for experiment due to the danger of catastrophic failure.
     
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  10. Chris-in-LA

    Chris-in-LA Well-Known Member

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    That sounds more like coupling caps to me. They still need to be 450v. Adding more capacitance will pass more bass frequency, but, maybe you already knew that.
     
  11. william vogel

    william vogel Active Member

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    A 22uF would be in the power supply section of the preamp as the OP referred to it as a “ node”. A coupling cap won’t be a 22uF.
     
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  12. Chris-in-LA

    Chris-in-LA Well-Known Member

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    Right, I was thinking of the .022uf coupling caps. In my defense, his schematic was drawn to look like coupling caps.
     
    Last edited: Aug 11, 2020
  13. william vogel

    william vogel Active Member

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    No harm. I think the important thing is that he understand that the voltage rating must be maintained in parallel circuits.
     
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  14. StingRay85

    StingRay85 Well-Known Member

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    Why not simply replace with a single 47nF?

    I would only apply these tricks when you want to switch one of them out of the circuit, or when the specific type of cap is hard to find. E.g. parallel 470nF with 220nF mustards to come to the desired 0.68.
     

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