The electromagnetic switch means that it is induced by a magnet. There are several types of magnets. Commonly used magnets in the market include rubber magnets, permanent magnet ferrites, and sintered neodymium iron boron. Most electromagnetic switches share the same design. When a small amount of current flows through the metal coil, the metal coil is used to generate a stable and predictable magnetic field. This turns the coil into a fine-tuned electromagnet. Inside the coil, the electromagnetic switch has a magnetic metal rod, which is firmly fixed, but loose enough to slide back and forth in the coil. When the coil is energized, the magnetic field drives the magnet rod to one end of the coil.