What is the Solenoid? – Selenoid is one of the electromechanical components that has an iron core that can move when given an electric voltage. For example The Selenoid 5V by Sparkfun. Inside a selenoid there are four elements is coil, spring, stationary core and iron core. The coil serves to generate electromagnetic fields. The spring serves to hold the iron core. Look at the picture below.
The working principle of selenoid
Selenoid will work if given an electric voltage on coil. When there is no electricity to the coil, the iron core will not move. If the coil is given an electric voltage (see in the picture below), then the electric current will flow in the coil and will produce an electromagnetic field around the coil. As a result of the electromagnetic field that occurs, the iron core and stationary core will have N-S pole, which will make the iron core move into selenoid. The speed of the movement of the iron core depends on the magnitude of the electromagnetic field produced by coil, springs and the attraction of the S pole of the stationery core in the selenoid.
Because the working properties of seleoid can move the iron core forward and backward when given voltage, selenoid use is found in many car door locks, homes, hotels, and in industries such as air, water, oil and gas valves.
Hopefully the article “What is the Solenoid” can be useful for you.