DC generator voltage regulator

Discussion in 'Power Electronics' started by rudyeb, Jan 29, 2018.

  1. rudyeb

    Thread Starter New Member

    Jan 3, 2018
    8
    0
    I am making a generator that is a very small geared DC motor. I need to put it inline to charge 4 Lithium or NiCad 1.5V batteries. I need some guidance on what would be the proper linear voltage regulator to use. The problem I see is that at times the generator may only put out 2-3 V based on its speed with a maximum output of maybe 20V. I need a VR that will handle both of these variables with it keeping the max output at 6VDC. Will I need any other components inline besides the VR?

    Thank you
     
  2. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    7,780
    1,914
    A current limiter and full charge detector.
     
  3. rudyeb

    Thread Starter New Member

    Jan 3, 2018
    8
    0
    I guess I didn't put my question properly, what would be the proper voltage regulator to use

    Thanks again
     
  4. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    7,780
    1,914
    What is the maximum current the motor will produce?
     
  5. rudyeb

    Thread Starter New Member

    Jan 3, 2018
    8
    0
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
    18,224
    5,593
    The best way to regulate a DC generator is obtain a motor with a wound field if you can find one now, it is very easy to implement, you may find an older automotive based one.
    Max.
     
    Last edited: Jan 30, 2018
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    9,731
    2,349
    Do you want to charge the cells in parallel or in series? If in series, will you be using a charge equaliser? There are ICs available for controlling that.
     
  8. rudyeb

    Thread Starter New Member

    Jan 3, 2018
    8
    0
    One other piece of info I failed to mention; the generator will be the input to a USB charger so I think all the necessary current limiter and full charge detector would already be in place.
     
  9. rudyeb

    Thread Starter New Member

    Jan 3, 2018
    8
    0
    The generator is to be a mobile means to supply power to a preexisting charger that is normally powered via a USB.
     
  10. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    9,731
    2,349
    Sounds like you need a buck-boost DC-DC converter rather than a simple regulator.
     
  11. rudyeb

    Thread Starter New Member

    Jan 3, 2018
    8
    0
    I am involved in this as a mentor to a student doing a STEM/STEAM project. My expertise is as a machinist and am helping him create his idea. My knowledge of electronics is fair but not at this level. If at all possible, I would really appreciate being directed to the proper unit to purchase for this application. Additionally, I intend to use a bridge rectifier to keep the DC polarity the same no matter which way the generator spins. Any assistance would be greatly appreciated.

    Thank you
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
    18,224
    5,593
    The advantage of the field regulator is that the rpm can be held at a high rpm with a constant regulated output, the bridge should work as a polarity steering bridge.
    Max.
     
  13. Andrei Suditu

    Member

    Jul 27, 2016
    33
    4
    Search for a dc-dc converter .A buck boost one .It keeps the output constant regardless of input as long as the input is between limits.Also i recommand to use an electrolytic cap after the bridge rectifier in order to smooth the input voltage to the regulator.Also parallel it with a 100nf cap for high frequency transients from the generator or any other input noise.
     
  14. Engr Tech

    Member

    Jun 24, 2017
    52
    1
    DC/DC converters take voltage from a Direct Current (DC) source and then converts it from a certain DC voltage level to another. They are used to raise or reduce the voltage level of supply voltage. They are often used in automobiles and household electronics.
    Source : blog.enrgtech.co.uk/dual-dcdc-converter-power-driver-modules/
     
Loading...