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Filtering capacitor

  1. Dec 7, 2012 #1
    Hello. I have a load powered at 1.4 V through rectifier bridge and capacitor 4700 µF. A residual ripple appears. As I need to eliminate this ripple I project to install a 1 F "saving capacitor " ( sorry I don't know the exact name in english ) as used to protect data in computers. Is there anything wrong in this project ?
  2. jcsd
  3. Dec 7, 2012 #2
    How much ripple appears?
    How much ripple can you tolerate?
    What is the frequency of the ripple?
  4. Dec 7, 2012 #3


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    Science Advisor

    Using very large capacitors will cause a problem with charging current. When you first apply power, a very large current will flow from the power source to the capacitor and this may well destroy the diodes and/or the transformer in the power source.

    It would be better to use a voltage regulator. You could consider the LM317K which could deliver voltages as low as 1.2 volts.
    Or if you have Ebay access, you could look for a step-down regulator (sometimes called a "buck" regulator) which would be more efficient.

    Just as an example, you can get these:

    This has current limiting, voltage output from 0.95V to 20 volts, current up to 3 amps, and costs less than US$5 delivered.
  5. Dec 8, 2012 #4
    Many thanks for your replies
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