http://upload.wikimedia.org/wikipedia/commons/1/10/Tesla_coil_3.svg theres no image tags on this forum? but yea 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?