Principle of operation:
The power supply has to charge the main capacitor first, and when the voltage reaches the discharge threshold of the lighter, the air in the lighter gap ionizes and fires, approximating the conduction, establishing a primary resonant circuit, which transmits the energy to the secondary circuit through oscillation. The secondary circuit then oscillates and receives energy, the voltage of the discharge topper gradually increases and ionizes the nearby air, 'looking' for a discharge path, and once a 'pathway' is formed with the ground, 'lightning ' also appears, if there is no 'lightning', a few (the number of times is mainly related to the coupling coefficient) weeks after the primary circuit energy release is complete. A larger portion of the energy is transferred to the secondary loop, and a portion of the energy is lost on the loop. Secondary circuit continues to oscillate, and the guest, drive the primary circuit oscillation, in the same way to just get the energy back to the primary circuit. But again part of the energy loss in the circuit, and so on and so forth (see the principle of demonstration diagram), until the loss of most of the energy. After the voltage and current at both ends of the lighter are insufficient, the lighter is equivalently disconnected, and the main capacitor continues to be charged by an external power source. The charging process is much longer than the discharging process, probably around 3 to 10 milliseconds. So the Tesla coil discharge frequency are more than 100 times per second, also make the naked eye looks for continuous discharge effect.