HIGH CURRENT VOLTAGE REGULATOR

Discussion in 'General Electronics Chat' started by HEALEY, Nov 10, 2004.

  1. HEALEY

    Thread Starter New Member

    Nov 10, 2004
    5
    0
    HAVE EXISTING DC SUPPLY, UNREGULATED CAPABLE OF 20 vdc @ 85A. REQUIRE REGULATION IN RANGE 10vdc TO 15vdc, AT 75 A.! YEP 75 AMPERES. CANNOT FIND ANY LITERATURE. THANX FOR YOUR SUGGESTIONS.
     
  2. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    1,437
    1
    hi

    as far as i know TOSHIBA has 12A (TA7812S), 7.5A by INTERNATIONAL RECTIFIER (IRU1175CMTR) and 7.5A by LINEAR TECH. (LT1083CP-12)

    you can check with this manufacturers :)

    the highest that i have done is a 25A regulated in parallel configuration. :)
     
  3. vhneumann

    New Member

    Dec 1, 2004
    4
    0
    Hello,

    There's a circuit at http://www.edn.com/article/CA434875.html that shows how to parallel integrated regulators. If you used LM350, at 3 amps each you would need 25 of them, plus diodes, capacitors. Also, as all ICs share the common terminal (tab in TO220, case in TO-3 package) they can be mounted on a single heatsink. Take note that for 25 devices, regulation terminal current amounts to 25X100uA=2.5 mA. Also, the circuit shown by EDN uses fixed regulators, common tab to ground, whereas using LM350 which needs two resistors to adjust voltage output you would need a common resistor coming out from the heatsink. Using a switching regulator with MOSFET pass transistor you might reduce power dissipation and size; don't know how to, but at the factory floor we use 24V 40A switching PSUs.

    Best regards
     
  4. vhneumann

    New Member

    Dec 1, 2004
    4
    0
    Hi there,

    Check circuits and also some theory about PWM regulation at

    http://www.edn.com/contents/images/31600di.pdf dimmer
    http://us.st.com/stonline/books/pdf/docs/3566.pdf dimmer
    http://users.pandora.be/educypedia/electro...uitsbypower.htm


    You can regulate the secondary side, using low voltage, high current MOSFETS - IRFZ44 - or regulate the primary side, using a TRIAC. I can remember repairing a little beast at a mechanic's shop; it regulated the primary side of thr transformer using a VERY SIMPLE triac circuit and rectifying the secondary with many diodes in parallel. This thing was used to charge 24/48 V batteries, also as a starter for truck motors. It was too simplistic, missed current sharing resistors in series with each diode at the secondary side. Maybe you could try a similar idea and improving upon the thery at the preceding links.

    Best regards
     
  5. 1000MFD

    New Member

    Dec 5, 2004
    4
    0
  6. vhneumann

    New Member

    Dec 1, 2004
    4
    0
  7. Karamuhlis

    New Member

    Dec 9, 2004
    1
    0
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