250kV Tesla Coil – Polakium Engineering

This is a 250,ooo volt tesla coil. It is powered by a standard 120 volt 60Hz US plug that powers a neon sign transformer with an output of 6kV at 30mA. The transformer is wired in parallel with two 10,000 volt capacitors for a total capacitance of 10nF. A pure tungsten spark gap is wired in series with the capacitors, one lead is attached to the capacitors and the other is attached to the 5 turn 3/16″ copper tube for the primary coil which attaches to the other end of the capacitors. The 450 turn secondary coil is wired to ground at bottom and to an 8″x2″ aluminum toroid as a top load. The primary and secondary coils act as a step-up transformer with a 6kV input voltage and 250kV output voltage. The toroidal terminal at the top serves as one plate of a capacitor while earth ground is the other plate. The open air discharges from the tesla coil produce arcs approximately 6-8″ in length while a grounded probe can draw arcs of about 10-12″.

The kit came with all of the necessary components including the base pieces, transformer, wire, capacitors, tungsten spark gap, 450 turn secondary coil and toroid.