I G,(jw) I
log scale
1
Low ti
scale
High cr
Figure 8.20. Bode diagram of a controlled second-order system indicating the effects changes in
the lag time constant, Ti .
SG,(jco) I 1/d
log scale
1 \ Oh log scale
1 1/Ti o i rad/sec
High Td
Low td
Figure 8.21. Bode diagram of a controlled second-order system indicating the effects changes in
the lead time constant, da.
system frequency response at a rate of 20 db per decade (10 fold increase in the input frequency)
for frequencies greater than 1/Ti or 0.5 rad/sec. Similarly, the lead time constant, td, would
cause a increase in the system frequency response of 20 db per decade, effecting frequencies
V
l/zi