The working principle of the ‌round tubular solenoid is to generate a magnetic field in the solenoid through current, which in turn drives the internal plunger to move. Specifically, when current passes through the wire of the solenoid, a uniform magnetic field is generated, which acts on the plunger inside the solenoid, causing it to move under the action of the magnetic field. When the current is disconnected, the magnetic field disappears and the plunger returns to its original position‌.

1.1.1‌-Current generates magnetic field‌: When current passes through the wire of the solenoid, the magnetic field around the wire becomes stronger. The direction and strength of this magnetic field depend on the direction and magnitude of the current.

1.1.2-Magnetic field drives the plunger‌: The plunger inside the solenoid is made of magnetic material, and when a magnetic field is generated, it moves under the action of magnetic force. This movement can be achieved through mechanical connection to achieve various functions, such as opening or closing a valve.

‌1.1.3-Current is disconnected, magnetic field disappears‌: When the current is disconnected, the magnetic field disappears, and the plunger returns to its original position under the action of a spring or other restoring force.