Know the Advantages of Solenoids
Solenoid is derived from the Greek words ‘solen’ which means a pipe or a channel and ‘eidos’ which means form or shape. A solenoid is simply a coil which is wound in tight helix. A solenoid essentially consists of a wire which is wound around a solid steel and iron. When current is passed through such a coil it becomes electromagnetically charged such that the movable core draws into the coil when current flows and it is this principle that is used for making a switch or in case of a mechanical device, a valve.
The applications of solenoid are immense and just some of these have been enumerated below.
Commercial appliances: Valves are essentially switches, the only difference being while the former controls mechanical devices the latter controls electrical devices. These solenoid valves therefore control the flow of hydraulic fluids and they often operate at pressures of around 3000 psi. These solenoids control the movement of oil to the actuators or rams. Such types of valves are often used in irrigation systems and also in our household appliances like the washing machine where they control the flow of water.
Automobile Industry: Solenoid is an integral part of the automobile ignition and starter system. Normally the starter solenoid receives very small current from the ignition and a very large current from the car battery. The moment you turn on the ignition switch pair of heavy contacts in the starter solenoid are closed thus allowing the larger current from the battery to flow. Often starter solenoids are built on the starter itself.
Electromechanical solenoids: They consist of an inductive coil which is electromechanical and wound around an armature. The coil is so wound so as to enable the armature to move from its mean position and thereby becoming an electromagnet by altering the coil’s inductance. This armature then provides the mechanical force necessary to move a mechanism for example a valve. The advantage is that they have a very short reaction time. Electromechanical solenoids are commonly used in pinball machines, fuel injectors, and dot matrix painters.
Security: Many automatic systems today incorporate solenoids. When in a locked position the solenoid does not consume power, however it needs a small current to unlock therefore some solenoids also incorporate battery packs. They are installed in high security areas, factories and offices.
Medical: With the advent of modern electronic machines, solenoids have increasingly become an important part of the medical field. They form an essential component of the dialysis machine, with a pair of two solenoids the dialysis machine controls the blood flow. A dosing machine which is used to ingest medicine into the blood flow also uses solenoids.