Chapter 15, Problem 1RQ

Name three types of automatic controls.

To determine

Automatic control and its three types.

Explanation of Solution

Automatic control system controls the system parts and its parameters such as starting and stopping the motor, close and open the valve, pressure, temperature, etc. Control system works electrically or mechanically. This automatic control system helps the system to work accurately and efficiently. Types of controls are given as follows:

Electric control

Control system works on the electric power. Electric control is power consuming or non-power consuming. Either the electric circuit or the magnetic coil are used in power consuming electric control system known as load. Non-power consuming control passes the power to the power consuming device known as switch. This combination of load and switch is used to control the system loads connected either in series or parallel.

Mechanical control

Mechanical control system works on the mechanical principal. All the device such as input, output and feedback are controlled mechanically. In NC machine all the device is controlled mechanically such as tool path, tool positioning, speed of jaw, tool positioning etc. Another example is of gear box in automobile that used to control the speed of the automobile.

Electro-mechanical control

This is the combination of both electrical and mechanical. It has advantages of both electric and mechanical systems. A device which work mechanically with electric operation is called electromechanical device such as electric motor. In motor, the input power is electric and mechanical rotating motion given by magnetic coils.