The problem of Power Supply Current Regulator.

Discussion in 'General Electronics Chat' started by mahammadmahdi, Aug 10, 2015.

  1. mahammadmahdi

    Thread Starter New Member

    Aug 9, 2015
    15
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    Hello dear SgtWookie:
    when i make regulatur current before regulatur voltag(1-current 2-voltag). out put voltag change very slowly when time i turn potonsivmeter. but it is ok when replace two regulaturs. ( 1-voltag 2 -current)
    what is your idea?




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  2. TheButtonThief

    Active Member

    Feb 26, 2011
    219
    38
    What regulators are you using?
     
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  3. crutschow

    Expert

    Mar 14, 2008
    13,001
    3,229
    The output voltage may change slowly if you have no output load on the supply.
     
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  4. mahammadmahdi

    Thread Starter New Member

    Aug 9, 2015
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  5. mahammadmahdi

    Thread Starter New Member

    Aug 9, 2015
    15
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    excuse i am mistake in picture to design out put. pol negative shuold conect to pol negative lm338
     
  6. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    1,248
    You need to pay more attention to the pinouts on the datasheets.

    The diode bridge is connected to the rest of the circuit backwards.
    You don't show pin numbers, but by your pictorial both 338's are connected incorrectly.
    Your circuit to charge pump a negative voltage into the 7909 is incorrect.
    The LM7909 is connected incorrectly.

    What is the purpose of the component marked 117?

    ak
     
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  7. mahammadmahdi

    Thread Starter New Member

    Aug 9, 2015
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    thanks of your idea
    its circuit was design of data sheet lm338 for regulatur voltage and so regulator current . forgive me i dont wrote number pin . problem me in regulator current . but its circuit correct work now. and out put 7909 consider pin in data sheet is ok. negative pin 7909 is for regulatur current by lm117 but its dont work correctly.
     
  8. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    What is the purpose of the component marked 117?

    What is the purpose of the 15 V zener diode at the LM7909 common pin?

    ak
     
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  9. mahammadmahdi

    Thread Starter New Member

    Aug 9, 2015
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    please read datasheet lm338
     
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