The term solenoid is a 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. The device creates a magnetic field from electrical current and uses the magnetic field to create linear motion. Common applications of solenoids are to power a switch like a starter in a generator or a valve in a sprinkler. The solenoid is a coil of wire in a corkscrew shape wrapped around a piston which is often made of iron. As in all electro magnets, 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.
Uses of Solenoids
Solenoids are incredibly versatile and extremely useful. They are found in everything from automated factory equipment to paintball guns and even doorbells. In a starter system the solenoid acts as a relay and brings metal contacts into place to close a circuit. The starter solenoid receives a small electric current when the ignition is activated. The magnetic field of the solenoid then pulls on contacts that close the circuit between the battery and the starter motor. It needs a constant flow of electricity in order to maintain the circuit. Once the generator engine is running the solenoid is once again inactive.
Characteristics of a faulty solenoid
It is time to change the solenoid when any of these faults occur. If the starter solenoid receives insufficient power from the battery it will fail to start the motor. Any problem with the solenoid often results in a rapid clicking sound. Wear and tear is a far larger problem in any unit that is used intermittently. The frequent on and off switching causes surges in power every time the unit is used. This often leads to heat build up and over time the solenoid will become less effective and parts may fail. Luckily this is an easy and affordable part to replace.