How does a solenoid work?

Answer 1

he solenoid of an autmobile is associated with the starter system and transfers an electric current into the starter motor to set the engine into operation. When the ignition key is turned, current is released from the battery and travels along an insulated wire into the solenoid. The solenoid then releases a small plunger that creates a connection between two internal electrical posts, sends the current down another wire to the starter and forces the starter motor to spin.

Answer 2

• Solenoid is the generic term for a coil of wire used as an electromagnet. It also refers to any device that converts electrical energy to mechanical energy using a solenoid. A device that creates a magnetic field from electric current and uses the magnetic field to create linear motion. Common applications of a solenoid are to power a switch, like the starter in an automobile, or a valve, such as in a sprinkler system.
• A solenoid is 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.
• In a direct-acting valve, electric current activates the solenoid, which in turn pulls a piston or plunger that would otherwise block air or fluid from flowing. In some solenoid valves the electromagnetic field does not act directly to open the conduit. In pilot-operated valves, solenoid moves the plunger which creates a small opening, and pressure through the opening is what operates the valve seal. In both types, solenoid valves require a constant flow of electrical current to remain open as, once the current is stopped, the electromagnetic field disperses and the valve returns to its original closed position.