Also included in this new volume 4 are three key US patents describing not only basic Cuk converter and its Isolated Cuk converter extensions, but also new general magnetics concepts: Coupled-Inductor and Integrated Magnetics. They are now proven to be equally beneficial for new switching methods and novel topologies invented recently by Dr. Cuk. After 40 years since its development, the enclosed description still remains as the most authoritative description. Subsequent Circuit Averaging modifications failed to justify the claim of "better insight" into converter models and Switch Averaged models failed to confirm the ease of use claim. Both "methods" are not even capable to model simple extensions such as addition of a voltage clamp let alone more complex topologies such as fundamentally new topologies with three switches only, invented by Dr. Cuk recently. The application of the State-space Averaging method also speeds-up naturally thousand times switching converter simulations and eliminates the inherent convergence and accuracy problems of all present simulation methods.