scientific and educational instruments:Three-ball instrumentThrough mechanical and electronic devices to control the operation of the day, month and earth, it can intuitively show the basic and typical operation state and trajectory of the "three balls" in the solar system, reflect the mutual position relationship between the three on any day in the four seasons of the year and their respective revolution, rotation, speed, orbital inclination, etc., and demonstrate the actual operation of celestial bodies very vividly, to make it easier for people to understand and understand this astronomical knowledge.

This instrument can also perform and explain the causes of the four seasons, the change of the moon phase, the law of the moon's operation, the rotation of the sun, the causes of the eclipse of the sun, the formation of the period of the year, the month and the day, the change of the length of the day, the twenty-four solar terms, the ecliptic, the equator, the white road, the difference between the return year and the sidereal year and so on astronomical phenomena and the principle.

scientific and educational instruments:Three-ball instrumentThe structure

1, the sun: a red plastic sphere, its center and the earth's center of the same height.

2, the earth: it can observe the seven continents, the four oceans, the north and south poles, the Tropic of cancer, the equator and the international date line. And there are three cursors set to interpret the direct sunlight, the rays and the twilight time of a certain location, and their angles are perpendicular to the surface.

3. Moon: The average height of its center is the same height as the center of the earth. The size and distance of the day, earth and moon of this instrument can not be based on the actual proportion of the support, so the yellow and white road surface angle of 5 9 'is appropriately enlarged.

4. Four Seasons Plate: Indicates the names, orders and dates of the four seasons and 24 solar terms.

5. Moon phase disk: use it to indicate the position of the moon phase and the day and night on the earth.

6. Pointer: When the earth rotates, it indicates the seasons and solar terms on the earth.

7. The return component of the three-ball instrument: it is installed on the base shaft to rotate, one end of which is the operating handle, and the other end is the gear set that runs on the ground.

8. Turntable: to support the whole instrument.

9. Push handle: connect with the central tube sleeve, start the push handle to rotate the plus-turn assembly for demonstration.