The tank capacitor…
Front view, 70 x 0.47uf 1500v caps in five strings of 14 to give a value of 16.7nf at 21,000v. Looks like a chopping board, but really it’s a high voltage circuit board !
Back view, 70 x 10M 0.5W hv resistors to discharge the possibly lethal power stored after switching off. The row-connecting ‘bus bars’ are 2.5mm solid copper cable.
20/03/2004 – Ammendment – Following some more research, I have now doubled the size of the bus bars by soldering another 2.5mm wire along the existing ones. Although only for a very brief period, the currents flowing during discharge can easily reach 100A ! and any resistance equals lost power – you need to dump every ounce of power into the primary instantly.