A time-dependent nonlinear compensating network

SINCE ABOUT 1950 there has been a trend toward the the use of nonlinear circuit elements in servomechanisms. Previously such elements were avoided because of difficulties in handling nonlinear differential equations. With improved mathematical techniques and widespread use of digital and analogue computers, more use is being made of nonlinear compensating devices. Nonlinear compensators can usually be made to show significant improvement in performance over their linear counterparts but often at the cost of increased complexity and expense.