seven solenoids.
A solenoid switch is a device that uses a small amount of power to create a magnetic field that will create a connection to a much larger power source. These devices are usually contained in a cylindrical metal case that covers a metal coil, a metal rod, and four or more electrical connectors. These keys are extremely common on cars and devices with similar engines. In a car, a solenoid switch will take the connection created when the key is turned and use it to connect the car’s larger, more powerful battery to the car’s electrical system.
When the ignition key of a car is turned, the starter solenoid is activated.
Most solenoid switches share a basic design. A metal coil is used to create a stable and predictable magnetic field when a small amount of current passes through it. This essentially turns the coil into a precisely tuned electromagnet. Generally, a pair of connectors clip onto each end of the coil, which are connected to a low-power source.
Inside the coil, the solenoid switch has a metal magnetic rod that is securely fastened but loose enough to slide back and forth inside the coil. When the coil is energized, the magnetic field drives the bar toward one end of the coil. This is where the second set of connectors are located. When the rod is in place, it forms a circuit with the heavier connections and allows power to flow through the system. All of this is then encased in a metal casing to reduce corrosion and protect the system and its operators.
A solenoid switch allows the car’s battery to connect to the car’s electrical system.
While you can find a solenoid switch in many items, it is by far the most common in modern car starting systems. These systems generally use the same basic switch design. The circuit created by the ignition system when the key is turned is connected to the coils. This charges the coils and creates a strong connection to the car’s battery. Battery power supplies electricity to start the car.
These options are very predictable and reliable, which is why they are used so intensively. Since the solenoid switch contains no real mechanical or electrical parts, it is very difficult for the system to break. As long as the outer casing remains intact, the inner workings will stay dry and keep working for a long time. In general, the most common reason a solenoid switch breaks is corrosion on the connectors migrating from the outside to the inside.