In a Bipolar Tesla Coil does the voltage from each end switch signs?

[bobfrancis1980]

From what I understand the bipolar tesla coil emits a positive voltage on one end and a negative voltage on the other end.

My question is, if the coil emits a positive voltage on the left side and a negative voltage on the right side the current then reverses direction and a negative voltage is emitted on the left side and a positive voltage is emitted on the right side? This process happens over and over correct?

Bob

[klugesmith]

Correct.
For example, if the secondary is operating at 100 kHz, the left-to-right voltage difference reverses sign every 5 microseconds during each burst.
In a more conventional "unipolar" tesla coil, the voltage (with respect to ground) reverses many times within the duration of every spark.

[bobfrancis1980]

Good to know for sure.

Thank you very much for your response

Bob

[MechatEng2023]

The main difference is that the bipolar Tesla coil has both ends floating a high voltage. The unipolar version has a grounded secondary.
You will get sparks from both ends, but if you touch one end of it, the secondary capacitance increases and the secondary resonant frequency decreases.(Your body is capacitively coupled to ground, when you touch one end of a BPTC it turn into a grounded unipolar Tesla coil). But at this time, the primaey is at the center, when one side is grounded the center of the secondary is at high voltage. So you will need better insulation between the primary and secondary coils. In normal opeartion, when both ends are ungrounded, the center of the secondary is ideally at a low potential to ground.

[MechatEng2023]

And you can tune bipolar Tesla coils for 2 modes: Resonance in normal operation, when both ends are floating, and resonance when one side is grounded(like someone touching it).
In this video you can see the coil tuned to resonance ,when I touch one end the output voltage increases:

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And here, it is tuned to resonance in normal operation. When I touch one end the output voltage drops.
https://www.youtube.com/shorts/JtyMekEmqKg

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