Plasma speaker / "singing arc" - my first try

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  • Опубліковано 14 жов 2024
  • Me building a plasma speaker and came up with my own design - inspired by this video: • Giant Bluetooth Plasma...
    Thanks, Plasma channel :)
    I don't get to nearly the same voltage levels by the trashy transformer I used, but actually got by far better sound.
    I use a bridge configuration instead of the typical flyback configuration otherwise used for most DIY high voltage projects (because of it's simplicity and ability to boost the voltage)
    The bridge configuration is more efficient, and the transistors only need to block nothing more than the input voltage when turning off (no back EMF from the transformer added onto the input voltage) and don't have to deal with voltage spikes caused by leak inductance (which is why most flybacks need a snubber circuit or zener diode to not have the transistor fail by overvoltage).
    The bridge can't boost the voltage though - so the secondary needs more turns (voltage can't get higher than the input voltage times the ratio of turns between primary and secondary).
    But, most important for playing audio thru the arc, is that it have a much more linear response to the changes in duty cycle compared to a flyback configuration.
    For example a transformer that has 10 turns on the primary and 1000 on the secondary will (thoretically, not taking into count losses), boost the output voltage 20 times at 20% duty cycle, 40 times at 40%, 60 times at 60% and 80 times at 80%, 90 times at 90% and so on.
    A flyback with the same 1:100 ratio, has an output voltage of 25 times the input voltage at 20% duty cycle, 67 times at 40%, 150 times, at 60%, 400 times and at 80% and 900! times at 90%. While this makes it easier to reach very high voltages - that nonlinearity will distort the audio modulation heavily.
    I'm not sure if an ignition coil can be driven by a bridge though. The average duty cycle is higher and the core gets magnetized in 2 directions. The efficiency would probably be very poor because of core losses.

КОМЕНТАРІ • 2

  • @dannydetonator
    @dannydetonator Рік тому +1

    Ultimate electronoob's question: can you get the required current/voltage for this from batteries?

    • @Speeder84XL
      @Speeder84XL  Рік тому +1

      Sorry for the late answer - but UA-cam didn't notice me about your comment for some reason.
      But yes - this will run fine on batteries. That's pretty much my taught when designing it - but still choosed to design it for relatively high voltage, to also be able test and run it on my bench power supply, that can only output 5 A of current (otherwise the available power gets very low, if using a lower voltage).
      You may need to put some battery cells in series to get enough voltage (it will work down to 9-10 V, but the power output is better at 20+ V). It only pulled about 2-3 A at average when fed 24 V and tuned for best sound though. So that should be quite easy for most batteries - for example running it on 18650 cells. Power can also be increased quite a bit with another transformer and just adding bigger heatsinks for the MOSFETs.