Determining value of capacitor and resistor in voltage regulator circuit

Discussion in 'Homework Help' started by rajeshbro, Mar 15, 2009.

  1. rajeshbro

    Thread Starter New Member

    Feb 8, 2009
    Hi everyone,

    I have a circuit with an input 19.66 V AC RMS and frequency 1Hz.
    I have drawn thecircuit diagram for the voltage regulation of 9V DC output, 0.333A output. Could someone help me in figuring out the value of R1, R2, C2 please?

    Or if you know if there is easier way to get an output of uniform 9V and 0.333A, please let me know. I am using that output to charge 7 x 1.2 V AA 2700 mAH batteries.

    Hope someone can help me in this.

    Thank you.

  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    I'm puzzled, yet fascinated - where do you get 19.66V at 1Hz?

    Have you considered purchasing a mains operated charger?
  3. thatoneguy


    Feb 19, 2009
    For a constant 333mA current with 1Hz/19Vrms Input, large capacitors would be needed (ridiculously large).

    There are also easier designs for a constant current source, such as the LM317 Voltage regulator connected as a current source, shown in it's datasheet.
  4. rajeshbro

    Thread Starter New Member

    Feb 8, 2009

    I know, its not a normal frequency you would see daily. Thing is I have a DC generator connected to the leg with rack and pinion set up and when leg rotates back and forward over in 1 second you get an AC voltage with 1 Hz frequency. You are right thatoneguy, capacitor value im getting with trial and error method using CIRCUIT WIZARD is around 600mF

    I just want to know a theoretical way of doing this.

    thanks for reply guys.