1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Difference in capacitor configuration

  1. Oct 8, 2007 #1

    I am working on a project at the moment and I have the option of connecting my capacitors in a number of different ways. My question deals with the possible difference in time, resistance to my circuit depending on where I connect the leads. What I really want to know is if there will be a significant difference in performance between each of the configurations.

    For simplicity, I have attached an illustration made in Paint (forgive me please). The capacitors are connected in parallel.

    The configurations are listed from easiest, to the least-easiest. Of course there is not much of a difference from the easiest to the least-easiest, however I do believe that this is good information to know.


    Attached Files:

  2. jcsd
  3. Oct 8, 2007 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I think the best way to find out is to estimate or measure the resistances of the connections, and work out the different network impedances yourself. Depending upon the application, you will then see whether it makes a difference or not.
  4. Oct 8, 2007 #3
    Remember that resistance in parallel adds reciprocally, whereas capacitance in parallel adds directly; resistance in series adds directly, whereas capacitance in series adds reciprocally. So as an overall rule for your network, where you increase capacitance you decrease resistance, and vice versa. You may want to work toward an optimum product of capacitance times resistance, or generalized RC time constant for the circuit.
  5. Oct 9, 2007 #4
    Are you in the MHz range? If so, you must provide much more detail.

    For lower frequencies and large caps, the technique I've always used is to strap the caps together with very large, very short, conductors. I've even used stranded braid. If you do that, the question is moot.

    If these are small caps on a board, simply minimize lead length.
  6. Oct 9, 2007 #5
    Thank you vanesch and Loren Booda for your replies!

    I have not calculated the exact value yet, however it will likely be on the order of a couple hundred Khz. They are pretty sizable doorknob capacitors, at 1400pF. To connect them I am using braided 8 gauge wire (aka, car battery jump cable). I can list off much more precise details as needed. Thanks!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook