Charging/Discharging Capacitors

Discussion in 'The Projects Forum' started by 8-bit, Feb 21, 2014.

  1. 8-bit

    Thread Starter New Member

    Jan 7, 2014
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    0
    I'm trying to figure out how I can have a capacitor charge and discharge in a simple circuit automatically and continually. Can somebody help. Thanks. :)
     
  2. ericgibbs

    Senior Member

    Jan 29, 2010
    2,499
    380
    hi,
    We need more information about your project.
    Capacitors, Voltages, Currents and charge/discharge times etc.

    E
     
  3. 8-bit

    Thread Starter New Member

    Jan 7, 2014
    27
    0
    Its not really a project, I'm just playing around with components and trying to figure stuff out. The circuit is powered by a 9v battery.

    I understand the capacitor will charge until it cannot charge anymore and also that it will only discharge when the current removed from it. I am trying to figure out how to achieve this.


    Thanks for the reply.
     
    Last edited: Feb 21, 2014
  4. raadalhmed

    New Member

    Feb 21, 2014
    1
    0
    thaaaaaaaaaaaaaaanks
     
  5. ericgibbs

    Senior Member

    Jan 29, 2010
    2,499
    380
    Connect one end a resistor from the +V of the 9V battery and the other end to the +V terminal of the capacitor [assumed polarised capacitor].

    Connect the -V of the battery to the -V of the capacitor.

    As soon as you complete the connections the capacitor voltage will rise exponentially. A DVM across the capacitor terminal will show this rise.
    It will fully charged to close to 9V in 5 Time Constants.

    When fully charged, disconnect the battery from the circuit and connect the free end of the resistor to the -V of the capacitor, the cap will discharge thru the resistor,, measure the Vcap with your DVM.

    Use this link.
    http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html
    E
     
  6. wayneh

    Expert

    Sep 9, 2010
    12,087
    3,027
    You might like to look up the "Blinky" circuit. It alternates flashing two LEDs and the timing is accomplished by charging and discharging capacitors. Fun and instructive project.
     
    8-bit likes this.
  7. BobTPH

    Active Member

    Jun 5, 2013
    782
    114
    Or an NE555 in the astable configuration. It works by alternately charging an discharging a capacitor, and the way it does so would be quite instructive.

    Bob
     
  8. 8-bit

    Thread Starter New Member

    Jan 7, 2014
    27
    0
    Many thanks for the info guys. Will check out the circuits you mention. :)
     
  9. Papabravo

    Expert

    Feb 24, 2006
    10,135
    1,786
    8-bit likes this.
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