Tesla Coil help?

Discussion in 'The Projects Forum' started by ice109, Jun 7, 2007.

  1. ice109

    Thread Starter New Member

    Jun 7, 2007
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    http://x016.uploaderx.net/x/untitled3.JPG
    what happens in this circuit?

    I know what's supposed to happen is that the tank cap is supposed to charge until the gap breaks down and then you have an LC resonance circuit in the primary side that excites the LC circuit, composed of the coil inductor and the stray capacitance betwee nthe top load and ground, in the secondary.

    lol run-on sentence.

    what i don't understand is that if the capacitor charges to the voltage of the power supply, only, why would the gap breakdown due to the voltage across the cap and not the voltage across the power supply? isn't the voltage across the power supply the same voltage that will eventually be across the cap?
     
  2. ice109

    Thread Starter New Member

    Jun 7, 2007
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    no one????
     
  3. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    The primary inductance and the capacitor create a resonant circuit. The voltage across the inductor is "Q" times the voltage across the series circuit, where Q is the quality factor of the LC circuit (Google LC circuit, series resonance, etc.). So, if you have high Q, at resonance the voltage across the inductor is much higher than the voltage across the series circuit.
     
  4. ice109

    Thread Starter New Member

    Jun 7, 2007
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    i was asking about the cap? when does the gap overvolt?
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Sorry, I misunderstood your question. Before the gap fires, the voltage across the cap is in fact basically identical to the supply voltage (the output of the high-voltage mains transformer). When the gap breaks down, the fast risetime if the arc sets up high-frequency oscillations in the resonant circuit, creating the high voltages I described in the previous post.
    So, in summary, the mains transformer creates the voltage that fires the gap. The LC resonant circuit sustains it with high-frequency damped oscillations, which get refreshed every half cycle of the AC line.
    BTW, I am not a Tesla expert, just an old engineer. I described how I believe the Tesla coil works. I may be wrong.:rolleyes:
     
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