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Debugging Kromrey-Converter

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  • #16
    Debugging Kromrey-Converter little progress

    Tom C, Faraday88

    Thanks again for your hints. Meanwhile I found that I made a stupid wiring mistake. After fixing this, I have one extremely poorly working machine instead of one that works not at all.

    Will work on air gap and coil as said.

    My device now outputs a little voltage and it does not show the behaviour of accelerating with shortcut; instead it slows down. Thus it is just in "conventional" mode.

    Just to share: Made a little DoE (Design of experiments) changing, wiring combination, number of magnet stacks etc.
    Tom, the 2 magnet stacks in parallel work, they result in doubling the output voltage. Why do I have these cylinder magnets - just could not find other BaFe magnets that come closer in size.

    Here some results (don't laugh at it :-) ), all at 850 RPM +- 5 RPM; all V is AC
    all coils in Series:
    1 Magnet stack 1.46V
    2 Magnet stacks 2.88V
    Asymmetric: 2 Magnet Stacks on one side, one Magnet Stack on the other side (Silly, just tried): 2.23V

    2 coils parallel in series with 2 other parallel coils (2 coils on one core)
    1 Magnet stack 0.71V
    2 Magnet stacks 1.42 V

    In this configuration my coils have 0.4 Ohms in Total (too much, I know)

    Nothing exciting at all.

    I'll rebuild with proper air gap and coils and magnet poles... Looking at John's device, I really wonder how he could get 3 strands in parallel onto the coils with that length, that wire diameter and have such a thick iron core. Anyway I'll try.



    • #17

      The coil configuration should be in such a manner that it looks like 1 coil circuit wise, you do not want bucking fields in the coils. the coils should be NSNSNSNS you wont get circulating currents in the coils if the currents are fighting each other. when the rotor passes over the pole pieces closing the magnetic loop the current induced in the coil poles must not fight each other, it will just cancel out. coils should be in series, in such a way that when the loop is closed, the corresponding poles at each end of the coil that are created when the magnet passes by (its the change in flux of the core that is doing the work) match the direction of the magnetic current in the stator pieces. you want the coils to all discharge the same direction.

      its also important that your magnets are stacked in a loop, you don't want 2 stacks of magnets all south on one end north on the other, you want a magnetic loop. you may have already done this, I just wanted to be clear.

      Tom C

      experimental Kits, chargers and solar trackers


      • #18

        the pole pieces are machined with a groove in them.... that's how there is so much the wire on the poles.

        Tom C

        experimental Kits, chargers and solar trackers