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Posts posted by jhanus

  1. Thank you,

    I understand first and the second recommendation and I will implement calibration trimpots.

    But just for my knowledge, how to connect two pots in series if one has all three terminals connected.
    If each terminal comes to each terminal that is parallel, but how to realize connecting in series(in this circuit)?  ???

  2. Hi,

    I found at my local shop voltage regulator TL783 (http://www.ortodoxism.ro/datasheets/texasinstruments/tl783.pdf), it can regulate from 0-125V, I can't use any other regulator because my input voltage is 40VDC.

    Problem is that this regulator from characteristics can only deliver around 700mA output at input-to-output voltage differentials of 25 V, but I need 3A.

    So can somebody help me to add current boost like it's done here (http://ourworld.compuserve.com/homepages/Bill_Bowden/page12.htm#317pass.gif), under title "LM317T Voltage Regulator with Pass Transistor".

    In datasheet there is circuit for current boost, but I would prefer method above.

    How to calculate this components would be of great help, because there is high probability that I can't buy the same transistors.

    Thank you.

  3. It doesn't cost more to use 120 ohms for R1 so why not always use 120 ohms with an LM317?

    Exactly thats the answer I was looking for, so if there is no loss in voltage or current really why not always use 120ohm, if that puts us in secure area.

    I'm using LM317 and LM337 for (-25)-0-(+25)V DC, could I drop 1.25V to 0 with diodes at output?
    Can I put on the same coil with already LM337 another LM337 (parallel) to create -1.25V to eliminate 1.25V from positive regulator LM317,and vice-versa?!

    Thanks again!

  4. ;D thanks! audioguru  ;D

    I can't buy:- TIP31A, but I can TIP33C, and (BC548,2N2219).

                      - OPA445AP, but I can TL081CN (C=operating temperature 0=>+70,
                                                                        N=DIP8 package).
    Are they good substitution? 

    Under two paralleled 2N3055, just to connect B-B, E-E, C-C or something else.

    Thanks a lot.

  5. audioguru, thanks.

    When you said that they are in this thread, did you mean scattered, or in one place, if they are in one place(plz link) or if anybody is willing to put them in one place?, I can remake the circuit, list all the changes and upload for future viewers.

    If the answer is no, then I'm off to read,and I'll post as soon as possible my result.


  6. Hello, I'm new here, so I greet everyone!

    I found this project,and accidentally found this thread, I began reading but there are 85+ pages  :o , so plz, can someone tell me is anything wrong with this circuit?!

    In first few pages there was something about transformer and diodes,and in last some modifications?!  ???

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