Method and demonstration of three-wave-source wave disc for realizing fundamental frequency multiplication and frequency conversion

Abstract

The invention relates to a method and demonstration of a three-wave-source wave disc for realizing fundamental frequency multiplication and frequency conversion, which mainly comprises a three-axis driver, a right-angle rotating wire a, a right-angle rotating wire b, a right-angle rotating wire c, a water wave disc and duck down, the three-axis driver with the same rotating speed is characterized in that three rotating shafts with three rotating shafts with the same rotating speed are coaxially fixed with one sides of a right-angle rotating wire a, a right-angle rotating wire b and a right-angle rotating wire c respectively, the other right-angle sides serve as rotating radiuses, small balls are fixed to the end points of the right-angle sides, and the lowest points of the tracks of the small balls are located on the same horizontal plane; duck down is fixed on the inner side wall of the water wave disc; taking a right-angle rotating wire a as an example, N iron wires with the same radius are connected and fixed to a rotating shaft of the right-angle rotating wire a, N small spheres are sequentially fixed to the ends of N rotating radiuses, the included angle of the connecting lines of every two adjacent small spheres and the rotating shaft is 360 degrees / N, and a frequency multiplication wave source is achieved; asymmetric distribution of the N small spheres is changed, variable frequency waves are achieved, and more education functions can be added when the device is popularized in teaching.

Description

Technical Field

[0001] This patent relates to a method and demonstration of a three-wave source wave disk with fundamental frequency, harmonic frequency, and frequency conversion, and realizes the research of superposition and interference of several two-wave sources and three-wave sources, which belongs to the field of physical experiments. Background Technology

[0002] In university physics teaching, wave superposition and interference are important topics. Previously, demonstrations of wave superposition and interference were often based on two coherent wave sources, frequently using a water wave disk as an example. Students observed the interference phenomenon produced by two coherent wave sources on the water surface, effectively helping them understand the principle of interference. However, demonstrations of interference with three wave sources were lacking. Furthermore, demonstrations often involved a low-frequency power amplifier outputting to a loudspeaker, with two vibrating devices fixed to the speaker's diaphragm as the vibration source (wave source), thus achieving coherent wave source demonstrations. Another method involved using the eccentric rotation of an eccentric wheel motor fixed to a hacksaw blade to generate centrifugal force... Interference phenomena such as linear periodic motion driving an elastic rope to generate standing waves are achieved, but the eccentric wheel motor's standing waves appear as linear standing waves. Surface interference with a water wave disk device is relatively expensive, requiring two frequency output devices to drive two speakers to demonstrate different frequencies. These frequency adjustments are hidden within the instrument, making it difficult for students to grasp the superposition interference demonstration of same-frequency, harmonic, and other vibration sources (wave sources). Furthermore, publicly available literature demonstrates same-frequency interference as constant-frequency interference; what would happen if it were synchronous, variable-frequency (interference) superposition? How can teachers guide and cultivate students to use simple devices or materials around them to create intuitive, low-cost, multi-purpose vibration sources (wave sources) (same-frequency, harmonic, variable-frequency) for experimental investigation, and more effectively cultivate students' hands-on and innovative activities? This patent aims to solve this problem. This patent was completed with the support of the National Natural Science Foundation of China (Project No.: 11805107, 11405092), the Basic Research Funds for the Undertakings of Heilongjiang Provincial Universities (Project No.: 135209251), and the Heilongjiang Provincial Higher Education Teaching Reform and Application Project (Project No.: SJGY20170385). Summary of the Invention

[0003] This patent mainly addresses the problem of interference from three coherent wave sources and the superposition of incoherent wave sources. It primarily solves this problem through a combination of three synchronous shaving shafts, right-angle rotating wires, and a water wave plate on an electric shaver.

[0004] This patented technical solution: A method and demonstration of a three-wave source wave plate for realizing fundamental frequency multiplication and frequency conversion, mainly comprising a three-axis driver with the same rotation speed, right-angle rotating wires a, b, and c, a wave plate (a transparent plastic plate with equidistant grids on the bottom), and down feathers. Its characteristic is that the three-axis driver with the same rotation speed is a Philips electric shaver (model YQ6188) with three rotating shafts at the same speed, after removing the blade cover to expose the three rotating shafts. The three rotating shafts of the three-axis driver with the same rotation speed include shaft a, shaft b, and shaft c. c is horizontal and parallel to the water wave plate; the three-axis drive and water wave plate with the same rotation speed are both placed and fixed on the horizontal plate; right-angle rotating wires a, b, and c are all right-angled metal wires (all are lightweight metal wires and have no effect on the speed of the electric shaver), with a small ball (a small ball used to strike the water) installed at one end (the rotation radius end), and the other end is fixed to the corresponding rotating shafts a, b, and c respectively, and the axes of rotating shafts a, b, and c are respectively aligned with the axes of the corresponding right-angle rotating wires a, b, and c. The right-angled sides coincide (the center lines of the right-angled sides coincide and are fixed coaxially), with the right-angled side where the small ball is mounted serving as the radius of rotation (the small ball strikes the water surface once per revolution); the small balls on right-angled rotating wires a, b, and c perform circular motions in their respective vertical planes, and the lowest points of their trajectories are on the same horizontal plane (ensuring the same amplitude of vibration on the water surface in the wave plate); the wave plate (transparent plastic plate) is a transparent plastic square or elliptical plate, and down feathers are fixed to the inner wall of the wave plate (to reduce the impact of water ripples). Reflection on the sidewalls improves the experimental results; the right-angle rotating wires a, b, and c do not collide during rotation (the sum of the rotational radii of the three right-angle rotating wires is less than the distance between the center lines of any two of the rotating axes of right-angle rotating wires a, b, and c); the above-described setting of installing only a small sphere at the rotational radius end of each of the right-angle rotating wires a, b, and c is a structure of right-angle rotating wires in the case of a fundamental frequency (same frequency fundamental frequency) vibration source (wave source) (the structure of right-angle rotating wires of a fundamental frequency wave source);

[0005] How to manufacture a right-angle rotating wire structure for an Nth-harmonic fundamental frequency vibration source (wave source) (right-angle rotating wire structure for a frequency harmonic wave source)? Taking right-angle rotating wire a as an example, N iron wires of equal radius are connected and fixed (by welding, strong adhesive, or wire wrapping, etc.) on the rotating shaft of right-angle rotating wire a (right-angle rotating wire b, right-angle rotating wire c). N small spheres are fixed sequentially at the ends of the N rotating radii. The number N is a positive integer greater than 1. The N small spheres are in the same vertical plane perpendicular to the rotating shaft. The angle between the line connecting two adjacent small spheres and the rotating shaft (radius) is 360 degrees / N (the N small spheres are in the same vertical plane, and the small spheres hit the water surface N times per revolution, which is N times that when one small sphere is fixed on right-angle rotating wire a. The frequency is also N times the frequency. This is the concept of frequency multiplication referred to in this patent. The rotating shaft outputs N times to hit the water surface per revolution). Similarly, right-angle rotating wire b and right-angle rotating wire c can also be used to create a vibration source (wave source) with a frequency N times the fundamental frequency.

[0006] The right-angle rotating wire structure for manufacturing a frequency conversion vibration source (wave source): N small spheres are fixed at the rotation radius ends of right-angle rotating wire a (right-angle rotating wire b, right-angle rotating wire c), where N is a positive integer greater than 1. The N spheres lie in the same vertical plane perpendicular to the rotation axis. The angles (radii) between the lines connecting adjacent spheres to the rotation axis are not equal, resulting in unequal division of the vertical plane. Although the number of times each sphere strikes the water surface is still N per rotation, the number of strikes per rotation of the axis is significantly increased. The water surface is not struck uniformly at equal time intervals; this is the frequency conversion (N-fold frequency conversion) referred to in this patent. For example, taking N=3, the angle between the line connecting two adjacent small balls to the axis of rotation (radius) divides the three small balls into the same vertical plane (perpendicular to the axis of rotation), thus dividing them into 60 degrees, 120 degrees, and 180 degrees. Alternatively, the same vertical plane (perpendicular to the axis of rotation) containing the three small balls can be divided into other angular relationships as needed (thus dividing them into micro-frequency conversion cases such as 119.5 degrees, 120 degrees, and 120.5 degrees).

[0007] The aforementioned three-axis drive with the same rotation speed is a Philips electric shaver with three rotating shafts operating at the same speed. It can be connected to an external motor speed controller (e.g., a variable resistance control circuit current can be connected to the power supply path) to change the fundamental frequency. The shaver motor and the AC synchronous motor are fixed side-by-side, with torque transmitted via a belt. The AC synchronous motor outputs a signal, and the fundamental frequency is read and displayed using a multimeter frequency counter. The bottom of the water wave plate is marked with equidistant grids to facilitate observation of the interference image and its direction.

[0008] The experiment demonstrates how to place a certain amount of water in a water ripple dish (a horizontally placed transparent plastic dish). Adjust the water depth of the small balls on right-angle rotating wires a, b, and c, and observe the clarity of the resulting ripples. The ripples should be clear enough. The echoes from the side walls of the water ripple dish should be relatively weak (absorbed by the down feathers fixed to the inner wall). Ensure the experimental environment is free from wind and vibration. Turn on the switch of a three-axis drive at the same rotation speed (like an electric shaver switch). Adjust the number and spatial position of the small balls on right-angle rotating wires a, b, and c as follows for demonstration and observation (observation can be done visually or by recording on a large screen and adjusting the playback speed):

[0009] One experiment involved three right-angle rotating wires, a, b, and c, each with only one small sphere on its end. This represented three vibration sources (wave sources) of the same frequency and first harmonic (fundamental frequency).

[0010] 1) Adjust the lowest point of the trajectory of the small ball on the right-angle rotating wires a, b and c to be on the same horizontal plane. The right-angled sides of the right-angle rotating wires a, b and c, which serve as the radius of rotation, are parallel and the small balls are facing the same direction (the phase difference is zero).

[0011] 2) Adjust the lowest point of the trajectory of the small ball on right-angle rotating wires a, b, and c to be on the same horizontal plane. The right-angled sides of right-angle rotating wires a, b, and c, which serve as the radii of rotation, are parallel. The small ball on right-angle rotating wires a and b faces the same direction, while the small ball on right-angle rotating wire c faces a different direction from the small ball on right-angle rotating wires a and b, in the opposite direction (180 degrees phase difference).

[0012] 3) Remove the right-angle rotating wire c (leaving only two vibration sources (wave sources)). Adjust the lowest point of the trajectory of the small ball on the right-angle rotating wire a and right-angle rotating wire b to be on the same horizontal plane. The right-angle sides of the right-angle rotating wire a and right-angle rotating wire b are parallel to each other. The small ball on the right-angle rotating wire a and right-angle rotating wire b are facing opposite directions (one facing up and the other facing down, with a phase difference of 180 degrees).

[0013] Experiment 2: N small spheres were set on right-angle rotating wires a, b, and c. The small spheres were fixed at the ends of their respective rotation radii. The results were three harmonic vibration sources with N=2, N=3, and N=2, and three same harmonic vibration sources with N=2, N=2, and N=2, respectively.

[0014] Experiment 3: Remove the right-angle rotating wire c (leaving only two vibration sources (wave sources)). Set the number of small spheres N on the right-angle rotating wires a and b (fixing the small spheres at the ends of their respective rotation radii). The results are N=2 and N=3 different harmonic vibration sources, and N=2 and N=2 same harmonic vibration sources (initially, the rotation radii of the small spheres are all parallel to each other and in the same vertical plane).

[0015] Experiment 4: Frequency Conversion Superposition Demonstration. The right-angle rotating wire c is removed (leaving only two vibration sources (wave sources)). N small spheres are placed on right-angle rotating wires a and b, where N is a positive integer greater than 1. Each small sphere is fixed at its respective rotation radius end. The rotation radii of the N small spheres do not unequally divide the rotation plane (i.e., the right-angle rotating wire structure of the frequency conversion wave source: the rotation radii of right-angle rotating wires a, b, and c are each N, with one small sphere fixed at each rotation radius end. The N small spheres are in the same vertical plane perpendicular to the rotation axis, and the angles between the lines connecting adjacent small spheres and the rotation axis are not equal, unequally dividing the same vertical plane). During the demonstration, the initial state of the wave sources is the same, meaning the rotation radii of the corresponding positions of the respective wave sources face the same direction (the rotation radii of the two wave sources are parallel, synchronously superimposed with frequency conversion, and interferentially demonstrated), or the initial conditions are different, and the rotation radii of the corresponding positions of the respective wave sources only have one common direction.

[0016] In summary, the frequency of the vibration source can be changed by altering the fixed number N of small spheres on right-angle rotating wires a, b, and c, as needed. This can further change the frequency relationship between the individual vibration sources (wave sources). Alternatively, the asymmetrical distribution of N (N > 1) small spheres in the rotation plane can be used to achieve a variable-frequency vibration source (wave source). Furthermore, it can demonstrate the phenomenon of superposition (interference) of two wave sources with N times the frequency and N times the frequency, which provides a completely new design for further understanding the conditions of interference. This approach has significant characteristics and represents substantial progress.

[0017] The inspiration from this problem: Electric shavers discarded in daily life or with damaged blades often still have intact motor drives. These are mostly dual- or triple-disc shavers. Utilizing the fact that their two or three rotating discs, driven by a single motor, rotate at the same speed, we can modify them to transform circular motion into water-striking motion (achieving the effect of a linear vibration source (wave source) created by a speaker). This results in a simple demonstration of three-wave source vibration superposition interference with the same frequency and constant phase difference. Subsequent research explored how to achieve superposition of different frequencies (incoherent) on this basis. Could we use another motor (or electric shaver) with a different speed? Obviously, this adds another drive device. Could we modify it further? With this idea in mind, we considered: one revolution of a small ball strikes the water surface once; N small balls strike N times. How can the vibration source (wave source) be in a harmonic or variable frequency relationship? What phenomenon would occur if two vibration sources (wave sources) were synchronously superimposed (interference) with variable frequencies? It seems like a very good topic, but it requires in-depth thinking over a period of time to solve. This problem could be studied as a second-classroom project in university physics, which would have a positive effect on cultivating innovative research.

[0018] The beneficial effects of this patent are as follows: 1. By using a three-axis actuator with the same rotation speed, combined with right-angle rotating wires a, b, and c, each fixing a small sphere, three coherent wave sources with the same frequency (fundamental frequency) and constant phase difference are obtained. The interference of the three wave sources is demonstrated with the help of a water wave disk. This not only demonstrates the interference of existing dual wave sources (same phase, opposite phase), but also realizes the in-phase interference of three wave sources and the interference of two in-phase and one out-of-phase three wave sources. 2. By increasing the number of rotation radii (number of small spheres) of each of the right-angle rotating wires a, b, and c, they are symmetrically distributed on the rotating surface. 1. By dividing the plane of rotation into equal parts, different driving frequencies are obtained, achieving frequency doubling of each vibration source (wave source); 2. By changing the asymmetrical distribution of N small spheres (rotation radii) in the plane of rotation, a variable frequency vibration source (wave source) is achieved; 3. A visual demonstration of the interference (superposition) problem of synchronous and variable frequency wave sources of two vibration sources (wave sources) is achieved; 4. A demonstration of superposition interference of wave sources with the same frequency but different structures is achieved. The design is ingenious, low-cost, and easy to implement. It expands thinking in teaching and scientific research, cultivates students' innovative awareness and practical spirit, and its promotion in teaching will add more educational functions. Attached Figure Description

[0019] Appendix Figure 1 The schematic diagram of the principle structure of this patent includes: 1. a three-axis driver with the same rotation speed, 1-1. rotating shaft a, 1-2. rotating shaft b, 1-3. rotating shaft c, 2-1. right-angle rotating wire a, 2-2. right-angle rotating wire b, 2-3. right-angle rotating wire c, 3. water wave plate, 4. horizontal plate.

[0020] Appendix Figure 2 This is a schematic diagram of a right-angle rotating wire with N=3 rotation radii (fixed and installed), and a small ball fixed at the end of each rotation radius. That is, when the number of small balls N=3, it is a right-angle rotating wire with a frequency harmonic (third fundamental frequency) vibration source (wave source).

[0021] Appendix Figure 3 The diagram shows the structure of a right-angle rotating wire with N=3 rotation radii (fixed and installed), and a small ball fixed at the end of each rotation radius. That is, when the number of small balls N=3, the right-angle rotating wire is a variable frequency vibration source (wave source).

[0022] Appendix Figure 4 A schematic diagram of a structure for fixing N=6 screws in the side holes of a columnar rod. Detailed Implementation

[0023] As attached Figure 1A method and demonstration of a three-wave source wave plate for realizing fundamental frequency multiplication and frequency conversion, mainly including: a three-axis driver 1 with the same rotation speed, right-angle rotating wire a 2-1, right-angle rotating wire b 2-2, right-angle rotating wire c 2-3, a water wave plate (transparent plastic plate) 3, and duck down feathers. The characteristic is that: the three-axis driver 1 with the same rotation speed is a Philips electric shaver with three rotating shafts of the same rotation speed, model YQ6188, after removing the blade cover to expose the three rotating shafts. The three rotating shafts of the three-axis driver (1) with the same rotation speed include rotating shaft a 1-1, rotating shaft b 1-2, and rotating shaft c 1-3. Rotating shaft a 1-1, rotating shaft b 1-2, and rotating shaft c 1-3 are horizontal and parallel to the water wave plate 3. The three-axis driver 1 with the same rotation speed and the water wave plate 3 are both placed on a horizontal plate 4 and fixed. Right-angle rotating wire a 2-1, right-angle rotating wire b 2-2, and right-angle rotating wire c 2-3 are horizontal and parallel to the water wave plate 3. 2-3 are all right-angled wires (iron wires), with a small ball attached to one end (for striking the water), and the other end fixed to the corresponding rotating shafts a1-1, b1-2, and c1-3 respectively. The axes of rotating shafts a1-1, b1-2, and c1-3 coincide with the right-angled side of the corresponding right-angled rotating wires a2-1, b2-2, and c2-3, respectively. The right-angled side where the small ball is attached serves as the radius of rotation (the small ball strikes the water surface once per revolution). The right-angled rotating wires a2-1, b2-2, and c2-3... The small spheres on 2-3 (or the outer ends of the right-angled sides bent into identical rings) undergo circular motion in their respective vertical planes, and the lowest points of their trajectories are on the same horizontal plane (ensuring the same amplitude of the vibrations on the water surface in the water wave plate 3); the water wave plate (transparent plastic plate) 3 is a transparent plastic square plate, and duck down feathers are fixed on the inner wall of the water wave plate (transparent plastic plate) 3 (to reduce the reflection of water waves on the side wall, making the experimental effect better); the right-angle rotating wires a2-1, b2-2, and c2-3 do not collide with each other during rotation (the sum of the rotation radii of the three right-angle rotating wires is less than the distance between the center lines of any two of the rotation axes of right-angle rotating wires a2-1, b2-2, and c2-3); as mentioned above, the right-angle rotating wires a2-1, b2-2, and c2-3... The setup of installing only a small sphere at each of the rotation radius ends of 2-3 belongs to the structure of a right-angle rotating wire in the case of a fundamental frequency (same frequency fundamental frequency) vibration source (wave source) (right-angle rotating wire structure of fundamental frequency wave source);

[0024] As attached Figure 2Taking N=3 as an example, a right-angle rotating wire structure for manufacturing a vibration source (wave source) of three times the fundamental frequency is constructed. Three iron wires of equal radius are connected and fixed to the rotating shaft of right-angle rotating wire a 2-1 (fixed by welding, strong adhesive, or wire wrapping, etc.). Three small spheres are fixed sequentially at the ends of the three rotating radii. The three small spheres are in the same vertical plane perpendicular to the rotating shaft. The angle between the line connecting two adjacent small spheres and the rotating shaft (radius) is 360 degrees / 3 (the three small spheres are evenly distributed in the same vertical plane, and the small spheres strike the water surface three times per revolution, which is three times the number of times when only one small sphere is fixed to right-angle rotating wire a). Similarly, right-angle rotating wires b 2-2 and c 2-3 can also be used to manufacture vibration sources (wave sources) of three times the fundamental frequency.

[0025] As attached Figure 3 Taking N=3 as an example, the right-angle rotating wire structure for manufacturing a three-fold frequency conversion vibration source (wave source) is as follows: Three small spheres are fixed at the rotation radius ends of the right-angle rotating wire a 2-1 (right-angle rotating wire b 2-2, right-angle rotating wire c 2-3). The three small spheres are in the same vertical plane perpendicular to the rotation axis. The angle between the line connecting two adjacent small spheres and the rotation axis (radius) is not equal, and the three small spheres do not equally divide the same vertical plane. Although the small spheres still hit the water surface three times per revolution, the three small spheres do not hit the water surface evenly at equal time intervals per revolution of the rotation axis. The three rotation radii divide the rotation plane into 30 degrees, 90 degrees, and 240 degrees respectively.

[0026] The experiment demonstrates how to place a certain amount of water in a water ripple dish (a horizontally placed transparent plastic dish). Adjust the water depth of the small balls on right-angle rotating wires a, b, and c, and observe the clarity of the resulting ripples. The ripples should be clear enough. The echoes from the side walls of the water ripple dish should be relatively weak (absorbed by the down feathers fixed to the inner wall). It is also important to ensure a wind-free and vibration-free experimental environment. Turn on the switch of a three-axis drive with the same rotation speed, and adjust the number and spatial position of the small balls on right-angle rotating wires a, b, and c as follows for demonstration and observation:

[0027] One experiment involved three right-angle rotating wires, a, b, and c, each with only one small sphere on its end. This represented three vibration sources (wave sources) of the same frequency and first harmonic (fundamental frequency).

[0028] 1) Adjust the lowest point of the trajectory of the small ball on right-angle rotating wires a 2-1, b 2-2 and c 2-3 to be on the same horizontal plane. The right-angled sides of the right-angle rotating wires a 2-1, b 2-2 and c 2-3 that serve as the radius of rotation are parallel and the small balls are facing the same direction (phase difference is zero).

[0029] 2) Adjust the lowest point of the trajectory of the small ball on right-angle rotating wires a 2-1, b 2-2, and c 2-3 to be on the same horizontal plane. The right-angled sides of the right-angle rotating wires a 2-1, b 2-2, and c 2-3 as their respective radii of rotation are parallel. The small balls on right-angle rotating wires a 2-1 and b 2-2 face the same direction, while the small ball on right-angle rotating wire c 2-3 faces a different direction than the small balls on right-angle rotating wires a 2-1 and b 2-2, and is in the opposite direction (phase difference of 180 degrees).

[0030] 3) Remove right-angle rotating wire c 2-3 (leaving only two vibration sources (wave sources)). Adjust the lowest points of the trajectories of the small balls on right-angle rotating wires a 2-1 and b 2-2 so that they are on the same horizontal plane. The right-angled sides of right-angle rotating wires a 2-1 and b 2-2 are parallel to each other. The small balls on right-angle rotating wires a 2-1 and b 2-2 face opposite directions (one facing up and the other facing down, with a phase difference of 180 degrees).

[0031] Experiment 2: The number of small balls N on the right-angle rotating wires a 2-1, b 2-2, and c 2-3 is set as follows: N = 2, 3, and 2 for three harmonic vibration sources (wave sources), and N = 2, 2, and 2 for three same harmonic vibration sources (wave sources).

[0032] Experiment 3: Remove right-angle rotating wire c 2-3 (leaving only two vibration sources (wave sources)). Set the number of small balls N on right-angle rotating wires a 2-1 and b 2-2, respectively, for the cases of N=2 and 3 different harmonic vibration sources (wave sources), and for the cases of N=2 and 2 harmonic vibration sources (wave sources) of the same harmonic frequency (initially, the rotation radii of the small balls are all parallel to each other and in the same vertical plane);

[0033] Experiment 4: Frequency Conversion Superposition Demonstration. Remove right-angle rotating wire c2-3. Set (fixed) N=3 small spheres on right-angle rotating wires a2-1 and b2-2. The rotation radii of the three small spheres do not equidistantly divide the rotation plane, with the three radii dividing the rotation plane into 30 degrees, 90 degrees, and 240 degrees respectively. During the demonstration, the initial state of the wave sources is the same; that is, the rotation radii of the corresponding positions of the respective wave sources face the same direction (parallel).

[0034] Alternatively, the structures of right-angle rotating wires a 2-1, b 2-2, and c 2-3 can be replaced with the structure of a columnar rod side-hole fixing screw, that is, the structure of a columnar rod side-hole fixing screw:

[0035] As attached Figure 4 The structure replaces right-angle rotating screws a 2-1, b 2-2, and c 2-3 with a columnar rod side hole fixing screw. When N=6: the columnar rod sidewall has N identical threaded holes, which are evenly distributed in the same plane perpendicular to the columnar rod. N identical threaded rods are matched with these N identical threaded holes, each with an identical small ball fixed at its end. The N identical threaded rods are installed and fixed in the N identical threaded holes on the columnar rod sidewall, and all N identical threaded rods are in the same plane perpendicular to the columnar rod. The extensions of the central axes of the N identical threaded rods intersect at a point on the central axis of the columnar rod. The columnar rod is fixed on the corresponding rotating shafts a 1-1, b 1-2, and c 1-3, and the rotating shafts a 1-1 and b 1-2 are fixed on the same plane perpendicular to the columnar rod. 1-2. The axes of the rotating shafts c1-3 coincide with the central axis of the columnar rod. By fixing one screw (fundamental frequency) to the columnar rod, symmetrically fixing N screws (harmonics, where N is an integer greater than 1), and asymmetrically fixing N screws (variable frequency), the desired fundamental frequency source, harmonics source, and variable frequency source can be obtained. The advantage of this structure is that it is easy to replace without the need for welding, strong adhesive, or wire wrapping. Repeat the number and spatial position relationship of the small spheres in Experiments 1, 2, 3, and 4 described above to demonstrate the experiment and observe the phenomena. It can also demonstrate (with the same average frequency): the interference demonstration of two wave sources superimposed at three harmonics and three variable frequencies.

[0036] The three-axis driver 1 with the same rotation speed is a Philips electric shaver with three rotating shafts of the same rotation speed. It can be connected to an external motor speed controller (e.g., a variable resistance control circuit current can be connected to the power supply path) as a controller to change the base frequency.

Claims

1. A device for realizing fundamental frequency multiplication and frequency conversion using a three-wave source wave plate, mainly comprising a three-axis driver rotating at the same speed, right-angle rotating wire a, right-angle rotating wire b, right-angle rotating wire c, a wave plate, and down feathers, characterized in that: The three-axis drive with the same rotation speed is a Philips electric shaver, model YQ6188, with the blade cover removed to expose the three shafts. The three shafts of the drive are shaft a, shaft b, and shaft c, which are horizontal and parallel to the water wave plate. Both the drive and the water wave plate are fixed on a horizontal plate. Right-angle rotating wires a, b, and c are all right-angled wires bent into right angles, with a small ball attached to one end and the other end fixed to shafts a, b, and c respectively. The axes of shafts a, b, and c are respectively aligned with the axes of right-angle rotating wires a and b. The center lines of the right-angled sides of each of the three right-angled rotating wires (c, b, and c) coincide and are fixed coaxially. The right-angled side on which the small sphere is mounted serves as the radius of rotation. The small spheres on the three right-angled rotating wires (a, b, and c) undergo circular motion in their respective vertical planes, and the lowest points of their trajectories are on the same horizontal plane. The water wave plate is a transparent plastic square plate, and down feathers are fixed to the inner wall of the water wave plate to reduce the reflection of water waves on the side wall. The three right-angled rotating wires (a, b, and c) do not collide with each other during rotation. The above-described configuration of mounting only one small sphere at the radius of rotation of each of the three right-angled rotating wires (a, b, and c) is a structure of the right-angled rotating wire in the case of a fundamental frequency wave source. The right-angle rotating wire structure of the frequency doubling wave source: N iron wires of equal radius are connected and fixed on the rotating shafts of right-angle rotating wires a, b, and c. N small spheres are fixed sequentially at the ends of the N wires of equal radius. The number N is a positive integer greater than 1. The N small spheres are in the same vertical plane perpendicular to the rotating shaft. The angle between the line connecting two adjacent small spheres and the rotating shaft is 360 degrees / N. The right-angle rotating wire structure of the frequency conversion wave source: N small spheres are fixed at the rotation radius ends of right-angle rotating wires a, b, and c, respectively. The number N is a positive integer greater than 1. The N small spheres are in the same vertical plane perpendicular to the rotation axis. The angle between the line connecting two adjacent small spheres and the rotation axis is not equal, and the N small spheres do not equally divide the same vertical plane. Although the small spheres still hit the water surface N times per revolution, the N small spheres do not hit the water surface evenly at equal time intervals per revolution of the rotation axis. Alternatively, the right-angle rotating screw structure can be replaced with a columnar rod side hole fixing screw structure, that is, The structure of the columnar rod side hole fixing screw: The columnar rod sidewall has N identical threaded holes, where N is an integer greater than 1. These N identical threaded holes are evenly distributed in the same plane perpendicular to the columnar rod. N identical threaded rods are matched with these N identical threaded holes, each with an identical small ball fixed at its end. The N identical threaded rods are installed and fixed in the N identical threaded holes on the columnar rod sidewall, and all N identical threaded rods are in the same plane perpendicular to the columnar rod. The extension lines of the central axes of the N identical threaded rods intersect at a point on the central axis of the columnar rod. The columnar rod is fixed on corresponding rotating shafts a(1-1), b(1-2), and c(1-3), and the axes of these shafts coincide with the central axis of the columnar rod. By fixing one screw to the columnar rod, symmetrically fixing N screws, and asymmetrically fixing N screws, the required fundamental frequency source, harmonic frequency source, and frequency conversion source can be obtained. The experiment demonstrates how to place a certain amount of water in a water wave basin. Adjust the water depth of the small balls on right-angle rotating wires a, b, and c, and observe the clarity of the resulting ripples. Clear ripples are acceptable. The echoes from the side walls of the water wave basin should be relatively weak. It is also crucial to ensure a windless and vibration-free experimental environment. Turn on the switch of the three-axis drive with the same rotation speed, and adjust the number and spatial position of the small balls on right-angle rotating wires a, b, and c as follows for experimental demonstration and observation: One experiment involved three right-angle rotating wires, a, b, and c, each with only one small sphere at its end, representing three sources of the same fundamental frequency. 1) Adjust the lowest point of the trajectory of the small ball on the right-angle rotating wires a, b and c to be on the same horizontal plane. The right-angled sides of the right-angle rotating wires a, b and c, which serve as the radius of rotation, are parallel and the small balls face the same direction with zero phase difference. 2) Adjust the lowest point of the trajectory of the small ball on right-angle rotating wires a, b, and c to be on the same horizontal plane. The right-angled sides of right-angle rotating wires a, b, and c, which serve as the radii of rotation, are parallel. The small ball on right-angle rotating wires a and b faces the same direction, while the small ball on right-angle rotating wire c faces a different direction, in the opposite direction. 3) Remove right-angle rotating wire c, and adjust the lowest point of the trajectory of the small ball on right-angle rotating wire a and right-angle rotating wire b to be on the same horizontal plane. The right-angled sides of right-angle rotating wire a and right-angle rotating wire b are parallel to each other, and the small ball on right-angle rotating wire a and right-angle rotating wire b are facing opposite directions with a phase difference of 180 degrees. Experiment 2: N small spheres are set on right-angle rotating wires a, b, and c. The small spheres are fixed at the ends of their respective rotation radii. The cases are three harmonic wave sources with N=2, N=3, and N=2, and three same harmonic wave sources with N=2, N=2, and N=2, respectively. Experiment 3: Remove the right-angle rotating wire c, and fix the number N of small balls on the right-angle rotating wires a and b. Fix the small balls at the ends of their respective rotation radii. The cases are different harmonic wave sources with N=2 and N=3, and the cases are the same harmonic wave sources with N=2 and N=2. Experiment 4: Frequency Conversion Superposition Demonstration. Remove the right-angle rotating wire c. Determine the rotation radii N on right-angle rotating wires a and b. Set the number of small spheres to N, where N is a positive integer greater than 1. Fix the small spheres at the ends of their respective rotation radii. The rotation planes containing the N small spheres are not equally divided. During the demonstration, the initial state of the wave sources is the same; that is, the rotation radii at corresponding positions of the wave sources face the same direction. The demonstration can also showcase the superposition phenomenon of two wave sources with the same average frequency but different structures: N times the frequency and N times the frequency conversion. Replace the right-angle rotating wire structure with a columnar rod side hole fixing screw structure, and repeat the experiment in Experiment 1, Experiment 2, Experiment 3 and Experiment 4 above to demonstrate the number and spatial position relationship of the small spheres and observe the phenomena.

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