How to regulate voltage using TIP122

Discussion in 'General Electronics Chat' started by kithul godage Vijitha, Aug 8, 2017.

  1. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    I want to create small circuit for regulate when the higher than 14V DC.. Please help me if you can..
     
  2. ScottWang

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    Aug 23, 2012
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    How is the input V/I?
    How is the Vout?
     
  3. crutschow

    Expert

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    Need regulation accuracy, maximum current, maximum input voltage.
    What does it do below 14v?
     
  4. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.
     
  5. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    actually I hope to use this to Alternator, for charge the lead acid batteries. then 200Ah batteries are connect as parallel so I want to charge the batteries without over charging. because I want regulate alternator output, using TIP122.

    Input voltage is not constant value. it will change according to RPM of alternator. maximum current 80A.
     
  6. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    How many TIP122 do you have with you? Because a single of those transistors is only capable of handling 5A at most. And that's under ideal conditions. You'd end up with a rather inefficient circuit with numerous components to accomplish what you want.

    There are other options out there, such as MOSFETS. Is the use of TIP122 for your application a must?
     
    Last edited: Aug 9, 2017
  7. ScottWang

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    Aug 23, 2012
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    The circuit can't be that simple, because you want to build the batteries charger with high current.
     
    cmartinez likes this.
  8. crutschow

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    Normally alternators have a voltage regulator.
    Doesn't yours?
     
  9. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    yes of course it has a regulator, But I want to build new one
     
  10. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    it doesn't matter. I want to just create a circuit for apply Alternator. I haven't idea how to use MOSFET for regulate the voltage. please send me your idea. It will more helpful to me.
     
  11. ScottWang

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    Aug 23, 2012
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    Voltage regulator for Alternator:

    Vin = input voltage unknown (range?).
    Iin = input current 80A.
    Vout = input voltage unknown (14V?).
    Iout max = 80A * eff% = ? A (80A?)

    12V Batteries:

    Iout max = 200Ah
    Vout = 14V
     
  12. crutschow

    Expert

    Mar 14, 2008
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    Then use that to give the desired output voltage.
    It will be more efficient and take less parts.
     
  13. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    out put voltage must be 14V
     
  14. kithul godage Vijitha

    Thread Starter New Member

    Aug 8, 2017
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    yes I want to charge 12 V Batteries
     
  15. crutschow

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    And how is that not achievable by regulating the alternator output voltage?
     
  16. dl324

    AAC Fanatic!

    Mar 30, 2015
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    14V is not optimum for charging 12V lead acid batteries, nor is charging them in parallel.

    Go to batteryuniversity.com and study the requirements before you try to build a charger. You'll find that you need a timer and multiple voltages.
     
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