Automatic control system is a feedback control system with reference to the desired input or output can be constant or change slowly over time and its main task is to maintain the actual output is at the desired value by the disruption.
Figure 2.7 Water Level Control System Automatically
The use of automatic control systems in all fields of engineering today more and more widely used. This is due to the automatic control system has many advantages compared with conventional control systems (manual), namely in terms of speed, accuracy and the use of human labor is relatively less. Moreover, supported by the development of the world of electronics, pneumatic or hydraulic.
Many examples of automated control systems, some of which are control room temperature automatically cars, automatic voltage regulator in the electric power plant in the middle the electric power load variations, and automatic control of the pressure and temperature of the chemical process. In the automatic control system, there are constituent elements, namely:
a. Sensor / Transducer
The sensor is a component that detects the output or other information required in systematic control. While the transducer is a component that is able to change besaranbesaran non-electric (mechanical, chemical or others) into electrical besaranbesaran or otherwise.
The controller is a component, device or equipment (such as mechanical, pneumatic, hydraulic, electronic, or a combination thereof) that is capable of processing the input data from comparing the response of plant (the readings from the output of the plant) and reference desired to be ejected into a command data, or so-called control signals.
Actuator is a component, equipment or appliances (such as mechanical, pneumatic, hydraulic, electronic, or a combination of these things) that can process data command (control signal) to signal to the action of a plant. To more easily understand how the automatic control system, in Figure 2.7 is given an example of the control system automatically at water level control applications. In this section are no longer using a human operator to maintain the desired water level, but it uses a controller that works automatically, such as a float material and additional electronic components.
With these components can be known how much depth or height of the actual water level. Of physical quantities, ie depth / height in meter unit is converted into electrical quantities with units of voltage. Given this information, then the controller will generate a control signal which is processed earlier. Bias controller in the form of electronic circuits, microcontrollers, mechanical, pneumatic, hydraulic or a combination of them.
Because the control signal bisalangsung not be used to rotate the valve / pipe valve, this makasinyal signal must be converted first into action. Aktuatorlah which converts this signal. Actuator in this system can be an electric motor, pneumatic or hydraulic component parts.