Jean-Louis Naudin - 27 April 97 - Thanks to Fred B. Epps
The main characteristic of this device is that the energy needed to produce oscillations in the resonant-tank circuit and to supply useful power to a load is derived from the primary winding via parametric couplig term, i(dL/dt). There is no flux coupling L(di/dt) between the controler coil and the controled inductor. The flux paths of the two windings have independent existences.
This Variable Inductor ( VARIND 4.0 ) is the main component of my Parametric Power Generator (PPG) device currently in development.
The VARIND 4.0 : Design and Schemes