The downy woodpecker is virtually identical in plumage pattern to the larger hairy woodpecker, but it can be distinguished from the hairy by the presence of black spots on its white tail feathers and the length of its bill.
A programmable logic controller, PLC, or programmable controller is a digital computer used for automation of typically industrial electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or light fixtures.PLCs are used in many machines, in many industries.LC applications are typically highly customized systems, so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design. On the other hand, in the case of mass-produced goods, customized control systems are economical.
Automatic water level controller circuit is a simple engineering project. It can automatically switch ON and OFF the domestic water pump set depending on the tank water level.You can implement this motor driver circuit at your home or college using less costly components. The output of 555 is fed to a BC548 transistor, it energizes the relay coil and the water pump set is turned ON. 2  While the water level rises, the top level probe is covered by water and the transistor becomes ON.