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Desulfator Engine, Heavy duty, DIY, Overnight results.

Discussion in 'Automotive Electronics' started by Mosaic, Jul 3, 2017.

  1. Mosaic

    Mosaic Well-Known Member

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    Hi all:
    I'm starting a Hackaday project to open source my proven desulfator engine. This is a pulse charge engine for batteries outside the vehicle as it delivers 250W RMS capability to the battery with up to 800A pulses.
    https://hackaday.io/project/25741-desulfator-engine-for-climate-change-mitigation

    I am not open sourcing the whole automation project but I will support those who want to do it.
    This is for the DIY folks who need a stable pulse engine they can add controls to and experiment with. The battery cell pics are a b4 and after of the same cell showing the improvements.
    cell2-1020sg.jpg cell2-1240sg.jpg inductance.png Bosch1.jpg
     
  2. Mosaic

    Mosaic Well-Known Member

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    Ok, the first schematic and PCB layout are posted as are some ref. docs about design etc.
     
  3. dougy83

    dougy83 Well-Known Member

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    Hello. The schematic presumably shows a 6.6mF capacitor bank switched across a lead acid battery. What voltage are the capacitors charged to, and how frequently are they discharged into the battery?
     
  4. dave

    Dave New Member

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  5. Mosaic

    Mosaic Well-Known Member

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    36V, 400 to 700Hz.
     
  6. dougy83

    dougy83 Well-Known Member

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    Thanks. Wow, that's a lot of power. 36V discharged to 12V battery (say pulse cutout at 20V) at 400 Hz is >1kW. I might dial it back a bit and try with some dodgy SLA batteries I have needing treatment.
     
  7. Mosaic

    Mosaic Well-Known Member

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    Well, it might seem so, but a substantial amount of the pulses are lost to parasitics such as connector & cable impedance as well as in circuit impedance. Capacitor ESR must be kept to a minmum, I tested a number of capacitors before settling on the suitable type.
    Have a look at the 'scope trace for a pulse and you can see the actual power delivery. In reality I see around 33% efficency based on what the battery actually accepts when subtracting the associated heating losses from impedance inside the battery as well as the power delivery subsystems.
     
  8. shortbus=

    shortbus= Well-Known Member

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    Mosaic Would it be possible for you to post a JPEG of the schematic here, please? I don't use Eagle and it doesn't open with other CAD software for me. Thank you.
     
  9. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    EAGLE exports directly to PDF too, which might be better.

    JOhn
     
  10. Mosaic

    Mosaic Well-Known Member

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    Here's a 150
    dpi schematic.
    EagleCAD offers a free use license for viiewing and printing schematics and layouts
    Schematic-PulseEngine1.png
    Screenshot_1.png
     

    Attached Files:

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  11. shortbus=

    shortbus= Well-Known Member

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    I thought they make you pay now? Unless you have a tie to a school. Like John said, a PDF would be good too.
     
  12. tomizett

    tomizett Active Member

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    As ever, Mosaic, I tip my hat to your skill and hard work. It's heartening to see someone put this much effort into a project with such laudable goals.
    it's also very satisfying to see something we've seen discussed so much here on ETO reach a stage of "completion" .
     
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  13. Mosaic

    Mosaic Well-Known Member

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    The hackaday project link in the 1st post now carries the PDFs of the toner transfer layouts for easy DIY and parts placement pdfs.
     
  14. flatfootskier

    flatfootskier Member

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    I'm going to have to build one of these...

    Many thanks for the effort you've put in.
     
  15. Mosaic

    Mosaic Well-Known Member

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    The Drain and source traces require buttressing with solder braid or # 18AWG bare wire to carry the pulse currents.
     

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