Closed Loop Control System


Control system in which the output has an effect on the input quantity in such a manner that the input quantity will adjust itself based on the output generated is called Closed loop Control System.

Open loop control system can be modified in to closed loop control system by providing a feedback. This feedback automatically corrects the changes in the output due to external disturbance. Hence closed loop control system is called automatic control system.


  • Closed loop control systems are more accurate even in the presence of non-linearities
  • The sensitivity of the system may be made small to make the system more stable
  • The closed loop systems are less affected by noise.


  • Closed loop control systems are costlier and complex
  • The feedback in the closed loop system may lead to oscillatory response
  • The feedback reduces the overall gain of the system
  • Stability is the major problem in the closed loop system and more care is needed to design a stable closed loop system

Closed-loop controllers