How an automated electric circuit works.

If you are an electrical maintenance engineer in any industry, be it chemical , steel or textile industry all you need to do is make the electrical machine run.
yes that's it !
all other parts of the circuit are to make sure that the motor runs and stops according to the norms of the production.

          So the basic idea is

1. electrical machine (often a motor)  should start and stop when required .
2.  The whole electrical circuit should be automated.

          To achieve these two functions the electrical circuit consists of two component.

1. Power circuit.
2. Control circuit.
   
   power circuit consists of :
   1. A protection device called circuit breaker to switch off the power under fault conditions.
   2. A Switching device to switch on and switch of the power as required under normal conditions.
   3. The electrical machine to be operated .
   Control circuit consists of the components to control the Switching device installed in the power circuit.
   
   the whole function of the control circuit is to switch on and off this device under various normal operating conditions or fault conditions
   
   The Switching device:
   
   The switching device used in the power circuit is an electromagnetic mechanical switch, called a Contactor
   i.e.
   a switch that is operated by an electromagnetic phenomenon .
   to put it simply
   
   Normal piano key switch installed in your room operates when you press it from bottom half and switches off when you press it from the top half.
   An electromagnetic mechanical switch operates when you supply  electricity to it and switches off when the electrical supply stops .
   
   
   Now we should directly delve into the most basic electrical control circuit called the Direct on line starter or the DOL starter, because learning about all the component even before they are used can be over whelming.
   
   So yes ,
   The Direct Online starter.