The Turn Of The Century Electrotherapy Museum http://www.electrotherapymuseum.com Relay / Contactor Powered Tesla Coil Components include a normal contactor, 110V coil, at least one set of normally closed contacts, an electromagnet, capacitor, Tesla Coil. I am using a diode here for 110VDC operation. The setup is essentially the same as a "kicking coil" made from a contactor, but because of the low currents from the contact electromagnet coil an additional electromagnet or self-induction coil is placed in parallel with it. Simple but effective, low voltages. Slight sparking at contacts.  In this arrangements, there are two pairs of contacts - in this example, I put the stationary upper contacts in series to make a sort of "dual spark gap". Top view of contactor. Side view of contactor.  It acts as an independent interrupter for the power supply. Can also run from 110VAC, but operation is better with DC. Click here for a movie!