(2) Detecting component A device that senses changes in the controlled variable in the controlled object and converts it into electrical signals (such as voltage and current). The detecting component monitors and detects the running state of the process at the moment of production, and the output signal is the basis of the control, so the requirement is accurate, timely and sensitive.

(3) Comparison link Here, the feedback signal output from the detection element is compared with the given signal to determine the magnitude and direction of the deviation signal (positive and negative).

(4) Amplifying components Since the deviation signals are generally small, voltage amplification and power amplification are required to drive the execution. Amplifying components are now mostly transistor amplifiers or integrated amplifiers. The comparison component and the amplification component are combined, and some documents are referred to as controllers or regulators.

(5) Actuator The function of the actuator is to receive the amplified deviation signal, directly drive the controlled object, and change the controlled variable to reduce the deviation and achieve the control requirements.

(6) The controlled object (control object, adjusted object) refers to the production equipment or machine whose process parameters need to be controlled in the automatic control system. The heater in the packaging process, the automatic metering hopper, the motor in the speed control, and the like may all be controlled objects.