Page 400 - Power Electronics Handbook

Electrical machine control 389
d Sensor Sensor

Sensor

(a1

Sensor

(C) (d)
Figure 14.40 Electronic switching using transistors: (a) unidirectional operation;
(b)-(d) bi-directional operation

xx x X
xxxx x
x xx x
xx xxxx
X x xx
x xx xxx
x x x x
xxx xx x

Figure 14.41 Closed-winding four-segment commutator motor. The table gives the switching
sequence