Battery Charger

Discussion in 'General Electronics Chat' started by banzai, Nov 6, 2014.

  1. banzai

    Thread Starter Member

    Jan 3, 2014
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    Hi

    I got my eyes on a newly installed Smart battery charger for a battery bank the other day. I got the chance to open the charger cabin door, but much of the parts where behind a protection glass, so i wasn't able to read any part numbers. what got me wondering is how is these chargers able to adjust there voltage in such a wide range. I am sure it's not transformer taps, would it be IGBT's ???

    The charger is a 110VDC-out and 380VAC in. Voltage range is 90-140VDC if i recall this right.
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    It is likely a Switch-Mode Power Supply that is controlled-current when the batteries are initially discharged, and controlled-voltage as the battery bank approach full charges state. It likely uses a MCU to implement a sophisticated multi-state charging algorithm.
     
  3. banzai

    Thread Starter Member

    Jan 3, 2014
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    How is the voltage adjusted/controlled. Is it trough a IGBT by adjusting its gate voltage ?
     
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    The switch could be anything, but most likely IGBT or NFET. However, it is a SMPS, so the switching devices are driven with PWM.
     
  5. banzai

    Thread Starter Member

    Jan 3, 2014
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    So it is rapid ON/OFF we are taking about (PWM). I thought they varied the gate voltage in order to set the required output voltage, but that would waste much power.
     
  6. banzai

    Thread Starter Member

    Jan 3, 2014
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    So is it simply a switched mode power supply witch high current, high voltage mosfets or IGBT's and a smart controlling circuit ?
     
  7. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    As I said back in post#2, it is a SMPS, but it is anything but simple...
     
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