For the electromagnetic coil with the smallest space, generating the maximum magnetic field, we must be curious about it. Also want to find out how the electromagnetic coil is how to do it. The following is a small series I say for everyone. The moving iron core of the electromagnetic coil, when the valve is connected with the electric iron core coil, will be attracted to move, drive the valve core to move, thereby changing the state of the valve guide. Professionals may have heard of dry or wet, just refer to the coil of the working environment, the valve action, is no different. But we must know that the inductance coil and the iron core size of the hollow after the addition of the coil is completely different. Inductance, the former is much smaller than the latter. Alternating current at the same frequency, inductance for changes in the core position, it is in the presence of the wire, establish magnetic field, it is wound into a spiral magnetic field, thus achieve the minimum space, resulting in the maximum magnetic field.