Control of modern machinery

Power is transformed into work by the motion of a group of interconnecting elements in a machine. For facilitating motion, electrical motors are used. In some cases, a solenoid valve and cylinder piston assembly operated by a compressor or a pump also is used. In a motor, rotational motion is converted into linear mechanical motion by employing a rack and pinion arrangement connected to the motor shaft. In the second method, fluid pressure is applied to cylinder piston through a solenoid valve. Solenoid valve is a mechanical valve which is operated through an electrical coil. Lots of physical efforts and calibration is required in controlling a machine manually. In modern machinery, magnetic control, automatic control and semi-automatic control are preferred. Here control circuits are consisting of large number of relays which performs a large number of operations. Most preferable control mechanism is static control where static control devices are used. Digital logic gates are the common choice as static devices in control circuits.