Have not done this yet.

Background: In the SSG circuit a pulse of electricity to a coil is optimized to produce a large displacement current/radiant spike. With the use of a sensor coil (or related timing mechanism) the input pulses may be timed to rotate a rotor, giving one the addition of some mechanical energy without diminishing the radiant spike. In a 555 or arduino based solid state generator one can not easily obtain this mechanical energy as there is not an not appropriate timing mechanism in place. One may also not simply place a pick-up coil on top of a solid state generator as drawing energy off said pick-up coil would diminish the radiant spike. One needs a utilization of the mechanical energy produced by the magnetic flux that is independent of the need for adjustable timing of input energy pulses used in driving a rotor.

Proposed Modification: Take a small piezoelectric generator. Place a neodymium magnet on one side of the generator and place the other side of the generator flush against the core of the coil. Orient the magnet such that when power flows the magnet is drawn towards the core, compressing the piezoelectric generator. See this video https://www.youtube.com/watch?v=ACsy6xSIBm8 for a rough idea of the dimensions involved, force needed, and power generated. Piezoelectric discs are quite inexpensive. For a solid state generator one might place one buzzer on each side of the coil, for an SSG set-up it is possible but by no means certain that placing the generator on the pole opposite the rotor might not appreciably interfere with the behaviour of the SSG.