CN206363620U - A kind of tuning fork resonance and vibrational image demonstrator - Google Patents

Abstract

A kind of tuning fork resonance and vibrational image demonstrator, belong to physical teaching aid, including glass box, Rotatable base, tuning fork, small eyeglass, built-in microphone formula audio amplifier, compact audio generator, fog machine, laser pen, nearside mirror, right reflective mirror, electronic six prisms reflective mirror, translucent plastic screen etc..The teaching aid not only can be used to observe phenomenon during tuning fork resonance, and may further be used to demonstrate the vibrational diagram of tuning fork.The teaching aid has reached the purpose of lasting resonance using audio amplifier driving tuning fork resonance；The problem of tuning fork vibration amplitude is small to be difficult directly observation is solved using light amplification principle；Using persistence of vision principle, experimental principle and method are ingenious, and experimental phenomena is substantially directly perceived, embody scientific, the pedagogical and inquiry and interest of teaching aid.

Description

A kind of tuning fork resonance and vibrational image demonstrator

Technical field

The utility model discloses a kind of resonance of tuning fork and vibrational image demonstrator, it is related to a kind of with reference to laser demonstration tuning fork The laboratory apparatus of covibration and vibrational image, belongs to physical teaching aid.

Background technology

In physics teaching, teacher is typically tested with two tuning forks come demonstrating resonance, i.e. sympathetic response is tested.It is in " Y " that tuning fork, which is, The steel or aluminium alloy acoustical generator of shape, various tuning forks can because of its quality and yoke length, thickness is different and is sent not in vibration The pure tone of same frequency.During experiment, take two intrinsic frequency identical tuning fork a and b and allow its resonant tank to place mouth to mouth, tap sound Fork a makes its sounding, and pinning tuning fork a with hand a moment later makes it stop sounding, can now hear the tuning fork b not being tapped Also it have issued sound.There are many deficiencies in the standard protocol：(1) because the loudness of tuning fork a shoos is inadequate, experiment is existing As not obvious enough；(2) because tuning fork vibration loss is obvious, cause the tuning fork vibration time short, it is impossible to continue sympathetic response；(3) tuning fork shakes Dynamic amplitude is small, is difficult directly observation.

The content of the invention

In order to solve above-mentioned deficiency, using light amplification and persistence of vision principle, design is a kind of to combine laser demonstration tuning fork The laboratory apparatus of covibration and vibrational image.The utility model is adopted the following technical scheme that：A kind of tuning fork resonance and vibrorecord As demonstrator, including glass box, Rotatable base, tuning fork, small eyeglass, built-in microphone formula audio amplifier, compact audio generator, cigarette Day with fog, laser pen, nearside mirror, right reflective mirror, electronic six prisms reflective mirror, translucent plastic screen etc., it is characterized in that：It is transparent Case specifically includes glass box body, stretches out one's hand operation elliptical aperture and black paper etc., and the black paper is pasted onto glass box trailing flank inwall As black background, allow laser beam to show and become apparent from, it is described to stretch out one's hand operation left side lower half position is located at elliptical aperture, it is convenient Device in glass box is operated；Fixed tuning fork, built-in microphone formula audio amplifier, the compact audio put occurs in glass box The devices such as device, fog machine, left and right sides inwall is pasted with nearside mirror and right reflective mirror respectively；Rotatable base is mounted in transparent Bottom portion, can be for rotating transparent case, convenient adjustment viewing angle；Tuning fork specifically includes resonant tank, prong and frequency modulation part, adjusts The position of section frequency modulation part can change the intrinsic frequency of tuning fork；Small lens sticker, can be with the starting of oscillation of tuning fork prong one in tuning fork prong It is dynamic；Resonant tank of the built-in microphone formula audio amplifier just to tuning fork, specifically includes speaker body, built-in microphone, audio amplifier switch, volume Adjusting knob and audio amplifier wiring etc.；Compact audio generator, specifically include audio-frequency generator body, switch, coarse adjustment frequency knob, Fine tuning frequency knob, digital display screen and output interface etc., can produce frequency for 0-1000Hz electric signal and be defeated by built-in Loudspeaker formula audio amplifier；Fog machine can produce a small amount of cigarette built with cake after lighting, it is possible to visualise the optical track of laser beam； Laser pen is fixed on glass box right flank inwall close to bottom position, can freely adjust its angle, the laser beam for allowing it to send Small eyeglass can be mapped to and be reflected on right reflective mirror, then pass through nearside mirror, right reflective mirror and electronic six prisms reflective mirror Multiple roundtrip is on translucent plastic screen；Electronic six prisms reflective mirror is fixed on glass box right flank inwall close to top Position, specifically includes six prism reflective mirrors, motor, motor power, power switch and speed governing knob etc., turns on the power switch Six prism reflective mirrors can be made to be rotated with motor；Translucent plastic screen is attached to glass box left surface inwall close to top position Put, specifically include screen body, rectangular co-ordinate and scale etc..

Principle of the present utility model is described as follows：During experiment, compact audio generator can produce the electricity of certain frequency Signal is simultaneously transported to built-in microphone formula audio amplifier, and built-in microphone formula audio amplifier can send the sound of corresponding frequencies, the sympathetic response of tuning fork Case and prong in the presence of sound so that make forced vibration.Resonance is met when the frequency of sound is equal to the intrinsic frequency of tuning fork Condition, now tuning fork prong vibration is most obvious.Because tuning fork prong is vibrated back and forth, the laser that laser pen is sent is anti-through too small eyeglass It can quickly swing, then be mapped to after the multiple reflections of nearside mirror, right reflective mirror and electronic six prisms reflective mirror up and down after penetrating On translucent plastic screen, so as to reach the sufficiently large purpose of multiplication factor in the limited space of glass box.Due to vision Principle is persisted, its laser beam shows one " triangle clear zone " and multiple " quadrangle clear zone " in the cigarette that fog machine is produced Optical track and show on translucent plastic screen one section " bright wisp ".When electronic six prisms reflective mirror is rotated, and due to vision Principle is persisted, can quickly show a sinusoidal vibrational image optical track on translucent plastic screen again.

(1) influence of the frequency to tuning fork vibration of audio amplifier sound is probed into

Exemplified by from intrinsic frequency for 440Hz tuning fork, during experiment, each device is fixed as requested, smog is lighted Cake in device sends a small amount of cigarette and is diffused into whole glass box, opens laser pen power supply, one is now only seen in glass box Bar incident ray and a plurality of reflection light.Then, the electric signal for allowing compact audio generator to send certain frequency makes built-in amplify Device formula audio amplifier sends sound, and trying one's best to heighten by volume adjustment knob keeps constant after volume, adjusted by compact audio generator The frequency of power saving signal increases to 500Hz from 400Hz, it can be seen that one " triangle clear zone " and multiple " four sides in glass box Shape clear zone " optical track, when incoming frequency is 440Hz, tuning fork vibration is most obvious, " triangle clear zone " and " quadrangle clear zone " optical track Area it is also maximum.During experiment, the intrinsic frequency of tuning fork can be changed by frequency modulation part, above-mentioned experimental procedure, Ke Yifa is repeated Now only when sound frequency is equal to the intrinsic frequency of tuning fork, tuning fork resonates.

(2) influence of the volume to tuning fork vibration of audio amplifier sound is probed into

During experiment, the frequency of input electrical signal can be kept constant, built-in microphone formula is changed by volume adjustment knob The volume of audio amplifier shoo, it can be found that wave volume is higher, tuning fork vibration is more obvious, " the triangle seen in glass box The area of shape clear zone " and " quadrangle clear zone " optical track is also bigger.

(3) the vibrational image experiment of demonstration tuning fork

When six prism reflective mirrors are not rotated, one section of " bright wisp " optical track is left on translucent plastic screen.When closure electricity Motivation power switch simultaneously adjusts rotating speed by speed governing knob, six prism reflective mirrors is turned with motor with certain rotating speed It is dynamic, due to persistence of vision principle, a sinusoidal vibrational image optical track can be quickly shown on translucent plastic screen.

Brief description of the drawings

Fig. 1 is the overall front view of the utility model；

Fig. 2 is the simple solid figure of glass box in Fig. 1；

Fig. 3 is the enlarged drawing of tuning fork in Fig. 1；

Fig. 4 is the enlarged drawing of electronic six prisms reflective mirror in Fig. 1；

Fig. 5 is the enlarged drawing of audio amplifier and compact audio generator in Fig. 1；

Fig. 6 is the schematic flow sheet of utility model works principle；

Fig. 7 is the design sketch in glass box when audio amplifier does not send sound；

Fig. 8 is the design sketch on screen when electronic six prisms reflective mirror is not rotated；

Fig. 9 is the design sketch on screen when electronic six prisms reflective mirror is rotated.

In figure：1. glass box, and in particular to 1a. glass boxs body, 1b. stretch out one's hand operation elliptical aperture and the black paper of 1c.；2. can Rotating base；3. tuning fork, and in particular to 3a. resonant tanks, 3b. prongs and 3c. frequency modulation parts；4. small eyeglass；5. built-in microphone formula Audio amplifier, and in particular to 5a. speaker bodys, 5b. built-in microphones, 5c. switches, 5d. volume adjustment knobs and 5e. audio amplifier wiring； 6. compact audio generator, and in particular to 6a. audio-frequency generators body, 6b. switches, 6c. coarse adjustment frequency knob, 6d. fine tunings frequency Rate knob, 6e. digital display screens and 6f. output interfaces；7. fog machine, and in particular to 7a. cigarette cases, 7b. cakes and 7c. cigarettes； 8. Laser pen；9. nearside mirror；10. right reflective mirror；11. electronic six prisms reflective mirror, and in particular to the prism reflective mirrors of 11a. six, 11b. motor, 11c. motor powers, 11d. power switches and 11e. speed governing knobs；12. translucent plastic screen, is specifically related to And 12a. screens body, 12b. rectangular co-ordinates and 12c. scales；13. laser optical track, and in particular to 13a. incident rays, 13b. Reflection light, 13c. " triangle clear zone ", 13d. " quadrangle clear zone ", 13e. " bright wisp " and 13f. " sine curve ".

Embodiment

The utility model is described in further detail below in conjunction with the accompanying drawings.

With reference to shown in Fig. 1-Fig. 5, a kind of tuning fork resonance and vibrational image demonstrator, including glass box (1), Rotatable base (2), tuning fork (3), small eyeglass (4), built-in microphone formula audio amplifier (5), compact audio generator (6), fog machine (7), laser pen (8), nearside mirror (9), right reflective mirror (10), electronic six prisms reflective mirror (11), translucent plastic screen (12) etc., its feature It is：Glass box (1) specifically includes glass box body (1a), stretches out one's hand operation elliptical aperture (1b) and black paper (1c) etc., the black paper (1c) is pasted onto glass box (1) trailing flank inwall and, as black background, allows laser beam to show and become apparent from, described to stretch out one's hand operation Left side lower half position is located at elliptical aperture (1b), it is convenient that device in glass box (1) is operated；It is fixed in glass box (1) Put the devices, the left and right sides such as tuning fork (3), built-in microphone formula audio amplifier (5), compact audio generator (6), fog machine (7) Face inwall is pasted with nearside mirror (9) and right reflective mirror (10) respectively；Rotatable base (2) is mounted in glass box (1) bottom, can be with For rotating transparent case (1), convenient adjustment viewing angle；Tuning fork (3) specifically includes resonant tank (3a), prong (3b) and frequency modulation Part (3c), the position of regulation frequency modulation part (3c) can change the intrinsic frequency of tuning fork；Small eyeglass (4) is attached to tuning fork prong (3b) On, it can be vibrated with tuning fork prong (3b)；Resonant tank (3a) of the built-in microphone formula audio amplifier (5) just to tuning fork, is specifically included Speaker body (5a), built-in microphone (5b), audio amplifier switch (5c), volume adjustment knob (5d) and audio amplifier wiring (5e) etc.；It is small Type audio-frequency generator (6), specifically includes audio-frequency generator body (6a), switch (6b), coarse adjustment frequency knob (6c), fine tuning frequency Knob (6d), digital display screen (6e) and output interface (6f) etc., can produce frequency for 0-1000Hz electric signal and be defeated by Built-in microphone formula audio amplifier (5)；Fog machine (7) can produce a small amount of cigarette (7c) built with cake after lighting, it is possible to visualise swash The optical track of light light；Laser pen (8) is fixed on glass box (1) right flank inwall close to bottom position, can freely adjust its angle, Its laser beam sent can be mapped to small eyeglass (4) and is reflected on right reflective mirror (10), then passes through nearside mirror (9), right reflective mirror (10) and electronic six prisms reflective mirror (11) repeatedly roundtrip on translucent plastic screen (12)；It is electronic Six prism reflective mirrors (11) are fixed on glass box (1) right flank inwall close to tip position, specifically include six prism reflective mirrors (11a), motor (11b), motor power (11c), power switch (11d) and speed governing knob (11e) etc., are turned on the power switch (11d) can be such that six prism reflective mirrors (11a) are rotated with motor (11b)；Translucent plastic screen (12) is attached to glass box (1) left surface inwall specifically includes screen body (12a), rectangular co-ordinate (12b) and scale (12c) etc. close to tip position.

With reference to Fig. 1 and Fig. 6, principle of the present utility model is described as follows：During experiment, compact audio generator (6) energy Produce the electric signal of certain frequency and be transported to built-in microphone formula audio amplifier (5), built-in microphone formula audio amplifier (5) can be sent accordingly The sound of frequency, the resonant tank (3a) and prong (3b) of tuning fork (3) in the presence of sound so that make forced vibration.When sound Frequency meets resonance condition when being equal to the intrinsic frequency of tuning fork (3), and now tuning fork prong (3b) vibration is most obvious.Due to tuning fork fork Stock (3b) is vibrated back and forth, and the laser that laser pen (8) is sent can quickly be swung up and down after being reflected through too small eyeglass (4), then by a left side Translucent plastic screen is mapped to after the multiple reflections of reflective mirror (9), right reflective mirror (10) and electronic six prisms reflective mirror (11) (12) on, so as to reach the sufficiently large purpose of multiplication factor in the limited space of glass box (1).Because the persistence of vision is former Reason, its laser beam shows one " triangle clear zone " (13c) and multiple " four sides in the cigarette (7c) that fog machine (7) is produced The optical track in shape clear zone " (13d) simultaneously shows one section " bright wisp " (13e) on translucent plastic screen (12), and specific effect is shown in Fig. 1 And Fig. 8., again can be in translucent plastic screen when electronic six prisms reflective mirror (11) rotates, and due to persistence of vision principle (12) the quick vibrational image optical track for showing a sine curve (13f) on, specific effect is shown in Fig. 9.

(1) influence of the frequency to tuning fork vibration of audio amplifier sound is probed into

As shown in fig. 7, exemplified by selecting intrinsic frequency for 440Hz tuning fork (3), during experiment, fixing as requested each Device, lights the cake (7b) in fog machine (7) and sends a small amount of cigarette (7c) and be diffused into whole glass box (1), opens laser pen (8) power supply, now only sees an incident ray (13a) and a plurality of reflection light (13b), specific effect in glass box (1) See Fig. 7.

As shown in figure 1, the electric signal for then allowing compact audio generator (6) to send certain frequency makes built-in microphone formula sound Case (5) sends sound, and trying one's best to heighten by volume adjustment knob (5d) keeps constant after volume, pass through compact audio generator (6) frequency of regulation electric signal increases to 500Hz from 400Hz, it can be seen that one " triangle clear zone " in glass box (1) (13c) and multiple " quadrangle clear zone " (13d) optical tracks, when incoming frequency is 440Hz, tuning fork (3) vibrates most obvious, " triangle The area of clear zone " (13c) and " quadrangle clear zone " (13d) optical track is also maximum.During experiment, it can be changed by frequency modulation part (3c) The intrinsic frequency of tuning fork (3), repeats above-mentioned experimental procedure, it can be found that only when sound frequency is equal to the intrinsic frequency of tuning fork (3) During rate, tuning fork (3) resonates.

(2) influence of the volume to tuning fork vibration of audio amplifier sound is probed into

With reference to Fig. 1 and Fig. 5, during experiment, the frequency of input electrical signal can be kept constant, passed through volume adjustment knob (5d) Change the volume of built-in microphone formula audio amplifier (5) shoo, it can be found that wave volume is higher, tuning fork (3) vibration is more obvious, The area of " triangle clear zone " (13c) and " quadrangle clear zone " (13d) optical track seen in glass box (1) is also bigger.

(3) the vibrational image experiment of demonstration tuning fork

With reference to Fig. 1 and Fig. 4, when six prism reflective mirrors (11a) are not rotated, one is left on translucent plastic screen (12) Section " bright wisp " (13e) optical track, specific effect is shown in Fig. 8.When closure electric motor power switch and passes through speed governing knob (11e) at (11d) Rotating speed is adjusted, makes six prism reflective mirrors (11a) with motor (11b) with certain rotational speed, because the persistence of vision is former Reason, can quickly show the vibrational image optical track of a sine curve (13f), specific effect is shown on translucent plastic screen (12) Fig. 9.

In a word, tuning fork resonance and vibrational image demonstrator not only can be used to observe tuning fork and are total to as a kind of physical teaching aid Phenomenon when shaking, and may further be used to demonstrate the vibrational image of tuning fork.The teaching aid has been reached using audio amplifier driving tuning fork resonance to be held The purpose of continuous resonance；The problem of tuning fork vibration amplitude is small to be difficult directly observation is solved using light amplification principle；It is temporary using vision Principle is stayed, experimental principle and method are ingenious, and experimental phenomena is substantially directly perceived, embody scientific, the pedagogical and inquiry of teaching aid And it is interesting.

Claims (7)

1. a kind of tuning fork resonance and vibrational image demonstrator, including glass box (1), Rotatable base (2), tuning fork (3), small eyeglass (4), built-in microphone formula audio amplifier (5), compact audio generator (6), fog machine (7), laser pen (8), nearside mirror (9), the right side Reflective mirror (10), electronic six prisms reflective mirror (11), translucent plastic screen (12), it is characterized in that：Fixed pendulum in glass box (1) Put tuning fork (3), built-in microphone formula audio amplifier (5), compact audio generator (6), fog machine (7), left and right sides inwall point Nearside mirror (9) and right reflective mirror (10) are not pasted with, and Rotatable base (2) is mounted in glass box (1) bottom, and electronic six prism is anti- Light microscopic (11) is fixed on glass box (1) right flank inwall close to tip position, and translucent plastic screen (12) is attached to glass box (1) Left surface inwall is close to tip position, and small eyeglass (4) is attached on tuning fork (3).

2. a kind of tuning fork resonance according to claim 1 and vibrational image demonstrator, it is characterized in that：Glass box (1) is specific Including glass box body (1a), operation elliptical aperture (1b) and black paper (1c) are stretched out one's hand, the black paper (1c) is pasted onto glass box (1) Trailing flank inwall allows laser beam to show and become apparent from as black background, described to stretch out one's hand operation and be located at a left side with elliptical aperture (1b) Side lower half position, it is convenient that device in glass box (1) is operated.

3. a kind of tuning fork resonance according to claim 1 and vibrational image demonstrator, it is characterized in that：Tuning fork (3) is specifically wrapped Resonant tank (3a), prong (3b) and frequency modulation part (3c) are included, the position of regulation frequency modulation part (3c) can change the intrinsic frequency of tuning fork； Small eyeglass (4) is attached in tuning fork prong (3b), can be vibrated with tuning fork prong (3b).

4. a kind of tuning fork resonance according to claim 1 and vibrational image demonstrator, it is characterized in that：Built-in microphone formula sound Resonant tank (3a) of the case (5) just to tuning fork, specifically includes speaker body (5a), built-in microphone (5b), audio amplifier switch (5c), sound Measure adjusting knob (5d) and audio amplifier wiring (5e)；Compact audio generator (6) specifically includes audio-frequency generator body (6a), switch (6b), coarse adjustment frequency knob (6c), fine tuning frequency knob (6d), digital display screen (6e) and output interface (6f), can be produced Frequency is 0-1000Hz electric signal and is defeated by built-in microphone formula audio amplifier (5).

5. a kind of tuning fork resonance according to claim 1 and vibrational image demonstrator, it is characterized in that：Fog machine (7) is built-in There is cake, a small amount of cigarette (7c) can be produced after lighting, it is possible to visualise the optical track of laser beam；Laser pen (8) is fixed on transparent Case (1) right flank inwall can freely adjust its angle close to bottom position, allow its laser beam sent to be mapped to small eyeglass (4) on.

6. a kind of tuning fork resonance according to claim 1 and vibrational image demonstrator, it is characterized in that：Electronic six prism is reflective Mirror (11) specifically includes six prism reflective mirrors (11a), motor (11b), motor power (11c), power switch (11d) and adjusted Fast knob (11e), turning on the power switch (11d) can be such that six prism reflective mirrors (11a) are rotated with motor (11b).

7. a kind of tuning fork resonance according to claim 1 and vibrational image demonstrator, it is characterized in that：Translucent plastic screen (12) screen body (12a), rectangular co-ordinate (12b) and scale (12c) are specifically included.