How can i compute the capacitor fliter for my ps?

Discussion in 'General Electronics Chat' started by rodel, Sep 26, 2006.

  1. rodel

    Thread Starter New Member

    Sep 26, 2006
    i've constructed a 24V, 2Amps power supply using a 7824 regulator ic. The problem is the output is only 23 volts. The voltage across the capacitor is already 35V. my transformer output is only 25V. the my capacitance is 10,000microfarad. how can i achive the 24V output of my ps?
  2. multi

    New Member

    Sep 21, 2006
    7824 is 1Amps regulator can u give me the details of yor no load voltage and its load current and voltage when connected to the power supply .
    connect 4k7,1/2w resistor across condensor.
  3. Søren

    Senior Member

    Sep 2, 2006

    As allready stated, the 78xx's are too "small".

    The peak of the rectified voltage is ~1.4 times the RMS voltage minus the diode voltage drops (around 1.3V in a bridge rectifier). The "25V" transformer rating is valid only at the rated load.

    That's ample for a load of 2A... Rule of thumb is 2,000µF/A.