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Control Systems - 1
Critically Damped System
Critically damped system
:
If the two poles of C(s)/R(s) are nearly equal, the system may be approximated by a critically damped one.
For a unit-step input, R(s) = 1/s and C(s) can be written
The inverse Laplace transform of the above equation may be found as
This result can be obtained by letting 
approach unity in equation given as
and by using the following limit:
