Referring to FIG. 9, an exemplary design of a printed circuit board embedding five transistor legs (of five corresponding switching cells) is illustrated, where each one of the five transistor legs (of the five corresponding switching cells) is positioned along one of the edges of a convex pentagon. The five edges of the pentagon have the same size. Each transistor leg includes two power transistors in series (only power transistors 100 and 200 are identified in FIG. 9 for simplification purposes). Five decoupling capacitors 500 respectively associated to the five transistor legs are represented. Five gate driver circuits 400 respectively associated to the five transistor legs are represented. Two DC input terminals (one positive 10 and one negative 20) and one output terminal 30 are represented. The respective positions of the positive 10 and negative 20 DC input terminals can be switched. A DC power ring 820 comprising a positive DC line connected to the positive DC input terminal 10 and a negative DC line connected to the negative DC input terminal 20 is represented.

The printed circuit board further comprises the fiberglass insulator 800 and the plurality of evenly distributed mounting holes 810 previously mentioned in relation to FIG. 8.

The present disclosure is not limited to transistor legs comprising power transistors in series, but can be generalized to transistor legs comprising any type of transistors in series.