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Capacitor auto-charge-discharge circuit

  1. Apr 14, 2012 #1
    Dear Experts,

    I am thinking of making a capacitor auto-charge-discharge circuit.

    Not sure if this is ok :

    Idea :

    1. hook-up a voltage comparator to the capacitor receiving charge.
    2. the other voltage comparator input pin connects to ground.
    3. make the comparator output a signal only when capacitor reaches 5v.
    4. when voltage comparator outputs a signal, it triggers a transistor switch that makes the opens the circuit on the wire from the power source to the capacitor +ve connector. So, capacitor will discharge through a short that is turned on when transistor is triggered.

    However, I am not very sure how the transistor should be used to open the circuit and close the circuit for discharge.

    Please let me know how you think about this method.

    Have a great day.

    Best regards
  2. jcsd
  3. Apr 14, 2012 #2


    User Avatar

    Staff: Mentor

    Hi ramonegumpert. Are you wanting to do this as a construction exercise to learn more about electronics, or do you have a practical need for such a circuit? If so, what is the need to do this, and how large is the capacitance?
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