CN209947213U - Double-vibration-source standing wave instrument - Google Patents

Abstract

The patent relates to a double-vibration source type standing wave instrument, which emphasizes on the technology of demonstrating a standing wave by using two same motors, leads and elastic ropes. The device comprises motor (1), elasticity rope (2), power (3), switch (4) and support bottle (5), characterized by: fixing a power supply (3) and a switch (4) on the side wall of a support bottle (5), fixing a motor (1) on a bottle cap of the support bottle (5), respectively fixing two ends of an elastic rope (2) on one side of rotating shafts of two identical motors (1), and supplying power to the motor (1) by the power supply (3) through a wire with an insulating sheath; the supporting bottle (5) is formed by putting a certain amount of sandstone into two hard plastic bottles with the same size and screwing a bottle cap. The device has the advantages that circular motion is not required to be converted into linear motion, so that mechanical loss is reduced; this patent design is through two vibration source counter-propagation on the elasticity rope, and it is the same that two rows of ripples amplitudes that meet in the middle part region of elasticity rope especially, the wave node is more clear.

Description

Double-vibration-source standing wave instrument

Technical Field

The patent relates to a standing wave appearance belongs to college physics demonstration instrument field.

Background

Vibration and fluctuation are important contents in college physics teaching, in order to demonstrate in class and class, people provide various standing wave demonstration instruments, such as standing waves formed in a magnetic field by ropes through alternating current, standing waves of a single motor driving rope and standing waves of a liquid Kuntte tube, the inventor and professor of Rong & Qing Hua university road and Hi Ling, and the like provide 'manufacturing of a portable longitudinal standing wave demonstration instrument' in 5 th year in 2010 and 'demonstrating and analyzing of non-uniform medium standing waves' in 4 th year in 'physics and engineering', which play an active promoting role in teaching, transverse standing waves and longitudinal standing waves of all experimental instruments are demonstrated, and the transverse standing waves are limited by observation visual angles, such as the demonstrating of the standing waves of the single motor driving rope, that generally the circular motion is changed into the linear motion (vibration) through a conversion device (such as a motor with an eccentric wheel is fixed on the center of steel with two fixed ends, realize the hacksaw blade and vibrate in single direction), make the equipment loss easily break down, and can only see obvious standing wave phenomenon from the vibration direction of perpendicular to rope and rope, be exactly perpendicular to rope and be on a parallel with the rope vibration direction (vibration source vibration direction) and see and be difficult to see standing wave phenomenon, and make the reflected wave and incident wave meet the department amplitude inequality in the rope middle part region because of the wave energy loss in the rope, the standing wave nodal department that forms has certain amplitude width rather than tending to the point (static point), how to see better ideal node, and the visual angle scope that can observe standing wave phenomenon is big, simple structure, with low costs, easy to carry out, the demonstration instrument that the effect is obvious, this patent is about to solve this problem. The method is completed under the support of national natural fund projects (project numbers: 11405092 and 11805107), basic business charge scientific research projects (project number: 135209251) of high schools belonging to provinces of Heilongjiang province and teaching, modification and application projects (project number: SJGY20170385) of the high schools belonging to the Heilongjiang province (the Cao le is a telecommunication 13-grade student of the Qizizall university).

Reference documents:

[1] fabrication of beam house, road and mountain ridge, Gunn, etc. [ J ] physics and engineering, No. 5 in 2010

[2] Demonstration and analysis of standing waves of heterogeneous media [ J ] physics and engineering in beam-law warehouse, Xubaochen, Liudousen, 2005, 4 th

[3] Theoretical analysis of beam-house, et al, gas flame standing wave demonstration experiment [ J ] physics and engineering, 10 th stage 2007

Disclosure of Invention

The patent solves a standing wave appearance, emphatically solves the technique that realizes demonstrating a standing wave with two same motors, wires and elastic ropes.

This patent technical scheme: a double-vibration-source standing wave instrument mainly comprises a motor, an elastic rope, a power supply, a switch and a supporting bottle, and is characterized in that: fixing a power supply and a switch on the side wall of a support bottle, fixing a motor on a bottle cover of the support bottle, respectively fixing two ends of an elastic rope on rotating shafts (one side) of two same motors (so that the two ends of the elastic rope have a rotating radius relative to the rotating shafts of the motors), and supplying power to the motors by the power supply through insulated conductors; the support bottle is formed by putting a certain amount of sand and stone into two hard plastic bottles with the same size and screwing bottle caps, the power supply is a 3-volt dry battery power supply, the rated voltage of the motor is 3 volts, the switch is a light touch switch, and the elastic rope is uniform and cylindrical, the diameter of the elastic rope is 2mm, and the length of the elastic rope is 60 cm.

During demonstration, the left hand and the right hand hold the two supporting bottles by hands, so that the rotating shafts of the two same motors are on the same straight line, then the fingers of the left hand and the right hand press the switches simultaneously to adjust the length of the elastic rope, so that the standing wave phenomenon can be seen, and along with the change of the length of the elastic rope, the visual effect situations of 1 antinode of 2 obvious nodes, 2 antinodes of 3 nodes and 4 antinodes of 5 nodes can be demonstrated at least. Moreover, the standing wave appears to be rotating, i.e. the observer can see the node antinode phenomenon of the standing wave in other directions than the rotating shafts of two identical motors on a straight line. And the switch is turned off when the demonstration is finished. Note that: before demonstration, the rotation direction of the motor is checked to enable the elastic rope to wind (rotate) in the same direction, and the effect is prevented from being influenced by the fact that the rope is curled and shortened.

Brief analysis: the elastic rope at the position of the rotating shaft of the fixed motor makes uniform angular speed circular motion around the axis of the rotating shaft of the motor at a small radius R, when the vision is observed in a direction perpendicular to the wave propagation direction (the connecting line of two motor shafts), the elastic rope at the position of the rotating shaft of the fixed motor makes circular motion and projects on a plane a which passes through the elastic rope (the connecting line of the two motor shafts) and is perpendicular to the connecting line of eyes and the elastic rope, and linear simple harmonic motion is formed on the plane a, namely the linear simple harmonic motion is perpendicular to the wave propagation direction, so that the standing wave vision effect of the wave node amplitude in a common textbook is formed, and the standing wave phenomenon can be observed in the direction which surrounds the elastic rope and is perpendicular to the elastic rope (the connecting line of the two motor shafts.

The beneficial effect of this patent: the uniform circular motion is not required to be converted into linear simple harmonic motion, so that the mechanical energy loss is reduced; compared with the prior art that a row of incident transverse waves are input at one end of an elastic rope and reflected on a reflection interface for superposition, the prior art demonstrates that due to energy loss (the actually used elastic rope has energy loss and is not ideal), the amplitudes of the incident waves and the reflected waves at the meeting positions near an incident wave vibration source are different (the amplitudes are the same only near the reflection end region), particularly when the elastic rope is long, the wave sections after superposition are not clear and fuzzy (people usually pay attention to the middle section of the rope during observation), and the length of the elastic rope is also limited; and this patent design is through two vibration source counter-propagation on the elastic cord, and two rows of wave amplitudes that meet are close the same at the middle part region of elastic cord very much, and the wave node is more clear. The beneficial effect of this patent: the device also has the advantages that the rotating standing wave is realized, and the phenomenon of node wave amplitude of the standing wave in the rotating state is formed by the fact that a plurality of spindle-shaped outlines are connected in series when the observation direction is not vertical to or not parallel to the direction of the elastic rope (the connection line of two motor shafts) due to the visual pause effect; the range of observable visual angles is increased, namely, the standing wave phenomenon can be seen only in the direction vertical to the wave propagation direction; the device has simple structure and easy implementation, and is a novel and interesting physical demonstration. The novel device generates a novel phenomenon, introduces teaching, expands the visual field of students, cultivates innovative spirit and practical ability, provides a reliable and novel experimental device for further theoretical learning research, and has more educational value when used in teaching.

Drawings

Fig. 1 is a schematic structural diagram of the patent, wherein: 1. motor, 2 elastic rope, 3 power supply, 4 switch and 5 supporting bottle

Detailed Description

As shown in the attached figure 1: a double-vibration-source standing wave instrument mainly comprises a motor 1, an elastic rope 2, a power supply 3, a switch 4 and a support bottle 5, and is characterized in that: fixing a power supply 3 and a switch 4 on the side wall of a support bottle 5, fixing a motor 1 on a bottle cover of the support bottle 5, respectively fixing two ends of an elastic rope 2 on one side surface of a rotating shaft of two identical motors 1 (so that the two ends of the elastic rope 2 have a rotating radius relative to the rotating shaft of the motor 1, and the two ends of the elastic rope 2 do circular motion around the central line of the rotating shaft of the motor when the motor rotates), and supplying power to the motor 1 by the power supply 3 through a wire with an insulating sheath; the support bottle 5 is put into a certain amount of grit by two hard plastic bottles of equidimension and screws up the bottle lid and constitute, power 3 is 3 volt dry battery power, 1 rated voltage of motor is 3 volts, switch 4 is the light touch switch, elasticity rope 2 is even column diameter for 2mm and natural state is 60cm long.

During the demonstration, two handheld two support bottles 5 of left and right sides, make two same motor 1's pivot on a straight line (motor 1's pivot and elasticity rope are on same straight line), stretch out elasticity rope 2 and be in natural length, then two hands finger presses switch 4 simultaneously about controlling, make two support bottles 5 intervals crescent, the length of elasticity rope 2 increases gradually, that is, along with the increase of 2 length of elasticity rope, can demonstrate in proper order on the elasticity rope of corresponding length: 2 nodes and 1 antinode, wherein the length of the corresponding elastic rope is a; 3 nodes and 2 antinodes, wherein the length of the elastic rope is b; and 5 nodes and 4 antinodes corresponding to the visual situation that the length of the elastic rope is c, wherein the length a of the elastic rope is less than the length b of the elastic rope and less than the length c of the elastic rope. Furthermore, the standing wave appears to be rotating (the visual pause effect is in a direction other than perpendicular to the elastic cord, and we see that several spindle-shaped profiles are connected together), that is, the observer can see the node antinode phenomenon of the standing wave in other directions without being in a straight line with the rotating shafts of two identical motors 1. The switch 4 is turned off when the demonstration is finished.

Note that: before demonstration, attention is paid to the connection between the power supply 3 and the motor 1, and the rotation directions of the motors 1 at the two ends of the elastic rope 2 are adjusted to be the same direction, namely the elastic rope 2 is wound (rotated) in the same direction relative to the connecting lines of the motors 1 at the two ends of the elastic rope 2.

Claims (1)

1. A double-vibration-source standing wave instrument comprises a motor (1), an elastic rope (2), a power supply (3), a switch (4) and a supporting bottle (5), and is characterized in that: fixing a power supply (3) and a switch (4) on the side wall of a support bottle (5), fixing a motor (1) on a bottle cap of the support bottle (5), respectively fixing two ends of an elastic rope (2) on one side of rotating shafts of two identical motors (1), and supplying power to the motor (1) by the power supply (3) through a wire with an insulating sheath; support bottle (5) and put into a quantitative grit in the hard plastic bottle of two equidimensions and screw up the bottle lid and constitute, power (3) are 3 volt dry battery power, motor (1) rated voltage is 3 volts, switch (4) are the light touch switch, elasticity rope (2) are even column diameter for 2mm and natural state is 60cm long.

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