To avoid confusing, both cases will be assumed that no self shoot-through
described in 1.2 is possible. However, there are many combinations, which make short
circuit happen. Therefore, one possibility of each case will be presented. In the first case,
short circuit across the dc source exists when switches S11 and S24 are turned on
simultaneously, which is illustrated in Fig. 2.9(a). Likewise, in the second connection,
when switch SA1 and SB3 are on at the same time, which is shown in Fig. 2.9(b), short
circuit will be happened.