CN201262793Y

CN201262793Y - Simulation demonstration instrument for stationary wave formation

Info

Publication number: CN201262793Y
Application number: CNU2008201226965U
Authority: CN
Inventors: 史建华; 杨旭东; 刘敏蔷
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2008-09-27
Filing date: 2008-09-27
Publication date: 2009-06-24
Anticipated expiration: 2018-09-27

Abstract

A wave formation simulation demonstration instrument belongs to the field of teaching instruments. The wave formation simulation demonstration instrument can simulate the formation process of standing waves and is used for classroom teaching. The instrument comprises a square framework 2, a rotating screen 1 and a background board 3 which is drawn with a standing wave contour line and is characterized in that transparent thin films drawn with sine waveforms are connected end-to-end, and sine waves are continuous to from the rotating screen 1; rotary shafts 4 are arranged at the two sides of the framework 2, the rotating screen 1 is tightened and sleeved on the two rotary shafts 4, and a crank 5 is arranged on one rotary shaft; and the background board is positioned at the back of the rotating screen 1 and fixed on the framework 2. In addition, a detachable non-transparent baffle sheet is arranged at one side of the framework 2; when the baffle sheet starts to block from a wave node of the standing wave contour line of the background to the side of the framework, the instrument can demonstrate the full wave reflection phenomenon; when the baffle sheet starts to block from a wave loop of the standing wave contour line of the background to the side of the framework, the instrument can demonstrate the half wave reflection phenomenon. The instrument can also demonstrate the full wave reflection and the half wave reflection phenomena caused by different spread media during the wave reflection.

Description

Standing wave forms simulated demonstration instrument

Technical field

The utility model belongs to the instruments used for education field.

Background technology

Standing wave is simple, the most basic phenomenon in the stack of ripple.When meeting, the phase of wave of the same amplitude of two row move toward one another, same frequency just forms standing wave.The phenomenon of standing wave and formation are the knowledge that requires the student to grasp in the physical basis teaching, and the forming process of understanding standing wave is the stack of back study ripple and the basis of wave interference, so the knowledge of understanding and grasp standing wave is an important link in the study.Though standing wave is simple, the most basic phenomenon in the stack of ripple, it also is suitable general phenomenon in the life, that but people's sense organ often is difficult to is complete, feel this phenomenon visually, thereby people are not deep to the perceptual knowledge of standing wave, so, in teaching, use standing wave demonstrator to be very important for the student.The apparatus for demonstrating of standing wave has many, and the use in the teaching is also quite general, makes the Frequency Adjustable standing wave demonstrator of vibration source as what many Educational Instrument Factories produced with loudspeaker; Also useful eccentric motor is made the Frequency Adjustable demonstration device of vibration source.The phenomenon that these instruments produce is real standing wave, but because frequency is very fast, can not observe the shape of standing wave transient state, in order to observe the shape of standing wave transient state, also needs to use stroboscope.In addition, also can demonstrate the process that standing wave forms, form demonstrator, can simulate the process that standing wave forms visually as the projection standing wave with simulated mode.But above these instruments all need more equipment, also need power supply, and it is not too convenient to use on the classroom, and cost is higher.

The utility model content

The utility model provides a kind of device of simple simulation standing wave forming process, to make things convenient for the needs of classroom instruction.

Solution of the present utility model is: with an end to end transparent membrane as roller blind 1, draw continuous sinusoidal waveform in the above, two rotating shafts 4 of roller blind 1 usefulness are strutted, rotating shaft 4 is placed on the square framework 2, and sets up crank 5 in a rotating shaft therein.Rotation crank 5 will make roller blind 1 turn over, and the sine wave on it also can move, and simulates the same amplitude of two row move toward one another, the ripple of same frequency.Settle a background board 3 that is decorated with the standing wave outline line in roller blind 1 back, make two train waves that simulation comes out amplitude and in the standing wave outline line, change.

In order to increase the friction force of rotating shaft 4 and roller blind 1, can on mandrel rod, put rubber ring.

In order to increase the stable and attractive in appearance of instrument, can below framework 2, settle base 6.

Whole wave reflection when this instrument can also be demonstrated wave reflection and half-wave reflex: one side,, can demonstrate whole wave reflection phenomenon when the node of catch from the standing wave outline line of background begins to block to the limit of framework at the catch of establishing of framework 2; When the antinode of catch from the standing wave outline line of background begins to block to the limit of framework, can demonstrate the half-wave reflex.

Press close to more for film before and after making, allow " two train waves " to reduce the collimation error, two last items 10 are set, the preceding film of roller blind 1 is pressed to rear film.In order to demonstrate the phenomenon of half-wave loss more easily, be arranged on the node place of standing wave outline line to last item 10 of major general simultaneously.

The beneficial effects of the utility model are: after adopting such scheme, wave propagation is that the people produces by crank, and velocity of wave propagation can be slow arbitrarily, also can rest on arbitrary position, can anatomize the situation of ripple stack like this.This instrument can also be demonstrated the situation of half-wave loss.This apparatus structure is simple, and cost of manufacture is low.

Description of drawings

Fig. 1: the front view of this instrument;

Fig. 2: the vertical view of this instrument;

Fig. 3: this instrument installs the situation of shutter additional;

Fig. 4: the front view when this instrument installs last item additional;

Fig. 5: the vertical view when this instrument installs last item additional.

Among the figure, 1, roller blind, 2, framework, 3, background board, 4, rotating shaft, 5, crank, 6, base, 7, shallow slot, 8, the shutter pilot hole, 9, shutter, 10, last item.

Embodiment

Framework 2 in this instrument is square frames, can use iron plate Laos system, also can use other material, as the picture frame shape.Place, two at the upper and lower side frame of framework is provided with the shallow slot 7 that rotating shaft 4 is installed, and wherein the top shallow slot is an open-work.Rotating shaft 4 is installed in shallow slot 7, and the framework upper side frame is stretched out in one of them rotating shaft, is used for installing crank 5.Crank 5 is installed in the position of tupelo, as Fig. 1 and Fig. 2.Roller blind 1 usefulness transparent membrane is made, and finishes sine wave on film, and film is from beginning to end, makes sine wave continuously, clings with transparent adhesive tape.Roller blind 1 is enclosed within two rotating shafts 4, and the position of shallow slot 7 should be that roller blind 1 is tightened in the rotating shaft 4 in the framework 2.In order to increase the friction force of 4 pairs of roller blinds 1 of rotating shaft, can in rotating shaft 4, overlap rubber ring or emulsion tube.Mounting seat 6 below the framework lower frame, and base 6 can be by iron plate Laos system, as Fig. 2.The background board 3 that is decorated with the standing wave outline line is fixed on the framework 2.

In order to allow this instrument can simulate the phenomenon of half-wave loss, can settle an opaque shutter 9 on one side of instrument, as shown in Figure 3.The position of shutter 9 will begin to block by the node of standing wave outline line from background.Shutter 9 can be hung in the shutter pilot hole 8.Situation for whole wave reflection can utilize rotating shaft as reflection spot, because rotating shaft place of this instrument is the position of standing wave antinode.

Fig. 4 and Fig. 5 are the situations that this instrument installs last item 10 additional.Last item 10 can make the front and back film of roller blind 1 press close to, and can reduce the parallax when side direction is watched this instrument; And last item 10 can also increase the friction force of 4 of roller blind 1 and rotating shafts.Last item 10 is similar to the installation of rotating shaft 4, is installed in the shallow slot 7 on the framework 2.

Claims

1. standing wave forms simulated demonstration instrument, comprising: quadra (2) and roller blind (1) and be decorated with the background board (3) of standing wave outline line is characterized in that: will be decorated with sine-shaped transparent membrane and join end to end, and make continuously sinusoidal wave, formation roller blind (1); Described framework (2) both sides are equipped with rotating shaft (4), roller blind (1) is tightened be enclosed within two rotating shafts (4), and settled crank (5) in a rotating shaft; Described background painting is placed roller blind (1) back, and be fixed on the framework (2).

2. standing wave according to claim 1 forms simulated demonstration instrument, it is characterized in that: described rotating shaft (4) is for being with the round metal bars of rubber ring.

3. standing wave according to claim 1 and 2 forms simulated demonstration instrument, it is characterized in that: on one side of framework (2) to the background board the standing wave outline line be provided with dismountable opaque catch from first node of this limit.

4. standing wave according to claim 1 and 2 forms simulated demonstration instrument, it is characterized in that: base (6) is installed below framework (2).

5. standing wave according to claim 1 and 2 forms simulated demonstration instrument, it is characterized in that: a last item (10) that the front and back film is pressed close to respectively is set near two rotating shafts (4).

6. standing wave according to claim 5 forms simulated demonstration instrument, and it is characterized in that: last item (10) is arranged on the node place of standing wave outline line.