In making this transition, animals hung on to the same switch arrangement and the same sets of regulators used by the ancestors, but they added a splendid additional idea.

Trajectory tracking in free space and torque tracking in constrained space are realized, and reliability of mode switch and stability of system are achieved in transition.

In common hard switching circuit, high voltage spike usually could be produced during switch transition process because of the effect of transformer leakage inductance and parasitic capacitor.