A coil of wire wrapped around a movable metallic core, or armature. When current flows through the coil, it generates a magnetic field that pulls or pushes the core to actuate a mechanism. Engineers use them to open valves, throw heavy switches, or trigger mechanical locks.
The starter solenoid is clicking but the motor won't turn over, so check the main power feed.
Solenoids draw a large surge of current when first energized, which drops off once the armature seats fully.
Do not mix it up with
- Relay: A relay uses a coil to close electrical contacts, while a solenoid generally performs mechanical work.
Related terms
Coil
A passive electrical component made of wire wound into a spiral or cylinder to create a magnetic field.
Relay
An electrically operated switch that uses a small control signal to toggle a much larger load circuit.
Inductor
A passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it.