Solenoids

Solenoids

A solenoid is a type of electromagnet, the purpose of which is to generate a controlled magnetic field through a coil. Wound into a tightly packed helix. The term was invented in 1823 by André-Marie Ampère to designate a helical coil.

How do Solenoids Work

A solenoid is a coil of wire in a corkscrew shape wrapped around a piston, often made of iron. As in all electromagnets, a magnetic field is created when an electric current passes through the wire. Electromagnets have an advantage over permanent magnets. In that they can be switched on and off by the application or removal of the electric current. Which is what makes them useful as switches and valves and allows them to be entirely automated.

Like all magnets, the magnetic field of an activated solenoid has positive and negative poles that will attract or repel material sensitive to magnets. In a solenoid, the electromagnetic field causes the piston to either move backward or forward, which is how motion is created by a solenoid coil.