Spinning Silver Egg

Through the model of three-phase asynchronous induction motor, understand the relevant knowledge of the rotating magnetic field generated by three-phase AC power, as well as the basic working principle of three-phase asynchronous induction motor. The exhibit consists of a booth, circular discs, silver hollow steel eggs, coils, protective covers, and handwheels. Press the start button and apply three-phase AC power to the three coils placed at a 120 degree angle to each other under the disc, generating a rotating magnetic field in space. The silver egg is a closed conductor, and the rotating magnetic field formed by the coil generates current and creates a magnetic field. The interaction between the two magnetic fields causes the silver egg to rotate. Due to the uneven distribution of silver egg mass, when it rotates rapidly, it stands upright under the combined action of centrifugal force and gravity, and as the rotational speed increases, the silver egg rotates faster and faster. Target audience: Adolescents aged 6-15. Display format: Electromechanical interactive device operation instructions (audience experience) 1.

Interaction type: Electromechanical interactive. The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

1. The exhibit is a model of a three-phase asynchronous induction motor, where the silver egg is equivalent to the rotor and the coil is equivalent to the stator. The reason why silver eggs can stand is that when the coil is connected to three-phase AC power (a power system composed of three AC circuits with the same frequency, equal potential amplitude, and phase difference of 120 °), a rotating magnetic field is generated in space. The machining center processes the magnet fixing plate to ensure that the three magnets are evenly distributed at a 120 ° angle. Due to the electrification of the lower coil, a rotating magnetic field is formed, and an electric current is generated inside the silver egg due to electromagnetic induction. The electric current is subjected to force in the magnetic field, and the silver egg slowly rotates synchronously with the magnetic field. When it rotates to a certain speed, under the action of centrifugal force, the silver egg slowly stands upright. The prototype of the rotating magnetic field is the "Columbus Egg" created by Tesla. 2. Three phase asynchronous motor is a type of induction motor that relies on the simultaneous connection of 380V.

Every unit leaves the factory after a running test: mechanisms cycled, electronics burned in, edges dressed, fixings torqued and marked. Wear parts — bearings, sliders, lamps, belts, touch panels — are modular and listed on the spare-part sheet, so a venue technician can replace them without returning the exhibit. Crating is plywood with foam blocking; the loading plan and packing list travel with the shipment.