A former employs a servant to look after his form house. He instructs the servant to
keep a watch on his goat. So that he does not harm the kitchen garden, when the
entrance-door is open. He is also required to see that no wild animal may pounce upon
the grazing goat. For this the former gives the servant a switch board, with three
switches marked as Door Open, Goat near Door & Wild Animal near by and instructs the
servant to press the appropriate switch, depending upon what he see, the switch
board has an alarm bell that rings when condition demands farmer’s attention suggest
a suitable switching circuit design for switching board.