CN2793849Y - Experimental device for magnet and non-magnet conductor inter-action - Google Patents

Abstract

The utility model discloses an experimental device for the interaction of magnetic and nonmagnetic conductors, which comprises a nonmagnetic metal air track, wherein the channel of which is provided with a plurality of photoelectric doors; the nonmagnetic metal air track is provided with a nonmagnetic metal sliding block; the nonmagnetic metal sliding block is provided with a magnet; the upper part of the nonmagnetic metal sliding block is provided with a light shielding piece; the outputs of the photoelectric doors are connected to a processing circuit of a single chip computer. The utility model is the improvement of the traditional air track experiment, so not only can carry out the original traditional air track experiments, but also can well analyze the law of the interaction force of a permanent magnet and a metal guide rail from the experiments. The utility model deepens the understanding action of students to electromagnetic induction phenomena, and is helpful to cultivate the explorative and the innovative abilities of the students.

Description

The experimental provision of magnet and nonmagnetic conduct or interreaction

Technical field

The utility model relates to a kind of experimental provision, the experimental provision of particularly a kind of magnet and nonmagnetic conduct or interreaction.

Background technology

Interaction effect between non magnetic motion conduct and static magnets or static non-magnetic conductor and motion magnet is widely used in the devices such as magnetic suspension bearing, magnetic brake brake, magnetic damping antidetonation and noncontact driving.Its interactional principle is based on the electromagnetic induction effect that the two produces when relative motion.But should the interaction system in the general physical textbook, not relate to substantially, only have the physicist Smith of the physicist's Landau of USSR (Union of Soviet Socialist Republics) and the U.S. that description than system was arranged in electrodynamics in the world yet.Experiment about motion magnet and nonmagnetic conduct or interreaction power, because the interference of external force such as gravity and friction force under the general condition, be not easy to obtain accurate quantification and experimental result repeatably, thereby in general Experiment of College Physics, seldom have the experiment of this class to leave, only there are some to glide in copper or aluminum pipe as permanent magnet qualitatively or interaction phenomenon that the lecture experiment of damped oscillation one class of metal in magnetic field is showed the electromagnetic induction generation.

People all adopt the motion conduct of rotation and the mode of action of magnet when the interaction in research motion nonmagnetic metal and magnetic field for many years.Owing to the introducing that rotatablely moves, increased the complicacy of interpretation.

The utility model content

The purpose of this utility model provides a kind of simple in structure, the magnet that cost is low and the experimental provision of nonmagnetic conduct or interreaction.

For realizing above-mentioned purpose, the technical solution of the utility model is: comprise the nonmagnetic metal air track, the passage of nonmagnetic metal air track is provided with a plurality of photogate, the nonmagnetic metal air track is provided with the nonmagnetic metal slide block, the nonmagnetic metal slide block is provided with magnet, the top of nonmagnetic metal slide block is provided with light barrier, and the single-chip microcomputer treatment circuit is received in the output of photogate.

In the above-mentioned magnet and the experimental provision of nonmagnetic conduct or interreaction, described magnet is a permanent magnet.

In the above-mentioned magnet and the experimental provision of nonmagnetic conduct or interreaction, the cross section of described nonmagnetic metal air track is a triangle, and described slide block is a herringbone, and the both sides of slide block are equipped with magnet.

In the above-mentioned magnet and the experimental provision of nonmagnetic conduct or interreaction, the spacing of described photogate is arbitrarily.

In the above-mentioned magnet and the experimental provision of nonmagnetic conduct or interreaction, described single-chip microcomputer treatment circuit is made up of multiselect one analog switch, CPU, display module, storer, expansion I/O module, keyboard, the output of multiselect one analog switch input termination photogate, CPU links to each other with output terminal, display module, storer, expansion I/O module, the keyboard of multiselect one analog switch respectively.

The experimental provision of a kind of magnet and nonmagnetic conduct or interreaction, comprise the nonmagnetic metal air track, the passage of nonmagnetic metal air track is provided with a plurality of photogate, the single-chip microcomputer treatment circuit is received in the output of photogate, the nonmagnetic metal air track is provided with the nonmagnetic metal slide block, the top of nonmagnetic metal slide block is provided with light barrier, is provided with at least one magnet on the path of slide block.

The beneficial effects of the utility model: the utility model is improved on traditional Air Track Experiment basis, can carry out original traditional Air Track Experiment, again can be well by the rule of the interaction force of experimental analysis permanent magnet and metal guide rail, both increased the content of Experiment of College Physics, the increase of the experimental facilities investment that significantly reduces again.Simultaneously, this experimental project is introduced in the physics experiment teaching, can be played the developing student thought, deepen the understanding effect of student, help to cultivate the student and explore creation capacity electromagnetic induction phenomenon.

Below in conjunction with the drawings and specific embodiments the utility model is further described.

Description of drawings

Fig. 1 is the structural drawing of the utility model embodiment 1.

Fig. 2 is the A-A cut-open view of Fig. 1.

Fig. 3 is a single-chip microcomputer treatment circuit block diagram of the present utility model.

Fig. 4 is the structural drawing of the utility model embodiment 2.

Fig. 5 is the A-A cut-open view of Fig. 4.

The induction current synoptic diagram that Fig. 6 permanent magnet of the present utility model produces in guide rail.

The speed that Fig. 7 records for different t constantly is by the result of (5) formula match.

Fig. 8 is the relation of non-magnetic conductor and movement velocity.

Embodiment

Referring to Fig. 1,2, this experimental provision comprises leg-of-mutton nonmagnetic metal air track 1, spaced set 8 photogate 5 on the passage of nonmagnetic metal air track, air track 1 is provided with nonmagnetic metal slide block 2, the slide block both sides are provided with two permanent magnets 3, the top of slide block 2 is provided with the light barrier 4 of band recess, photogate 5 is provided with optical transmitting set 6 and optical receiver 7, and the single-chip microcomputer treatment circuit is received in the output of optical receiver 7.

Referring to Fig. 3, the single-chip microcomputer treatment circuit selects 1 analog switch, CPU, display module, storer, expansion I/O module, keyboard to form by two four.The core of this single-chip microcomputer treatment circuit is the 89C55 single-chip microcomputer.Keyboard is used for setting the duty of experimental provision and imports the parameters such as width of light barrier on nonmagnetic metal slide block quality, the slide block.Eight photogate are divided into two groups, being connected respectively to one four selects on the analog switch (AD7501), their output is linked to INT0 and the INT1 of CPU respectively, can distinguish and write down exactly that slide block arrives the moment of each photogate and by their time, the benefit that adopts the two-way external interrupt is to distinguish the direction that slide block slides, and single-chip microcomputer just can be according to the corresponding photoelectricity passage of glide direction gating successively like this.After record finishes,, can calculate successively and show the moment, speed, momentum, the kinetic energy of slide block,, can calculate the acceleration of depicting slide block and suffered resistance change curve in time again by these data at each photogate place by operation keyboard.

The principle of work of this experimental provision: when sliding on the air track of the slide block that has permanent magnet at aluminium alloy, the magnetic field that the metal guide rail induced currents produces can react on the magnet on the slide block, and slide block is slowed down.In other several photogate of settling of air track, photogate is provided with light emission and optical receiver, when the process of the light barrier on slide block photogate, optical receiver does not receive signal, but the track record slide block arrives the moment and the speed of each photogate like this, follow the magnetic field intensity of quality according to known slide block, permanent magnet and size etc. again, just can be well by the rule of the interaction force of experimental analysis permanent magnet and metal guide rail.

The surface of magnet is parallel with aluminium alloy air track surface in this experimental provision, the vertical projection area L below magnet ₀* W ₀The magnetic field intensity at interior guide rail place is

Be zero outside projection in zone, be about to magnetic flux and constrain in the zone under the magnet.When magnet moved on air track with slide block, guide rail can produce the induced potential ε perpendicular to direction of motion in the projection plane below magnet.If be the electromotive force of battery further, with the projection plane L of magnet perpendicular to track with induced potential ε equivalence ₀* W ₀The equivalent resistance of the guide rail of surface area is internal resistance of cell r, and this extra-regional equivalent resistance is non-essential resistance R, and then the total induction current that is obtained being produced by induced potential in guide rail by whole circuit law of ohm is

I＝ε/(R+r) (1)

For width is L ₀, speed is the motion magnet of V, the quantitative relationship of ε can be designated as

Induction current and magnetic field interaction force

For

Only consider component along direction of motion, after variable is separated:

$\frac{\mathrm{dV}}{V}=\frac{{{\mathrm{<figure-callout\; id="0"\; label="L"\; filenames="Y20052004990700122.png"\; state="\{\{state\}\}">L</figure-callout>}}_0}^2{B_0}^2}{m(R+r)}\mathrm{dt}---\left(3\right)$

Obtain behind the integration:

$\mathrm{LnV}-\mathrm{Ln}{V}_0=-\frac{{{\mathrm{<figure-callout\; id="0"\; label="L"\; filenames="Y20052004990700122.png"\; state="\{\{state\}\}">L</figure-callout>}}_0}^2{B_0}^2}{m(R+r)}(t-t_0)---\left(4\right)$

Order $\frac{{L_{}}^{}}{}$ $\frac{{{}_0}^2{{\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="Y20052004990700122.png"\; state="\{\{state\}\}">B</figure-callout>}}_0}^2}{(R+r)}=k,$ Arrive the time t of first photogate ₀=0, the speed of this moment is designated as V ₀, the speed that then obtains any time is:

V＝＝V ₀e ^-kt/m (5)

By (5) formula as can be known, under motion magnet and metal guide rail interacted the effect of damping force of induction, slide block was done retarded motion by the negative exponent of time.As long as measure different V and moment corresponding t constantly, experimental data by (4) or (5) formula match, just can be tried to achieve the K value.Try to achieve after the K, can obtain the damping force that any time motion magnet is subjected to by (3) formula:

$\stackrel{\mathrm{\&rho;}}{F}=m\stackrel{\mathrm{\&rho;}}{a}=m\&CenterDot;d\stackrel{\mathrm{\&rho;}}{V}/\mathrm{dt}=-m\&CenterDot;\frac{{{\mathrm{<figure-callout\; id="0"\; label="L"\; filenames="Y20052004990700122.png"\; state="\{\{state\}\}">L</figure-callout>}}_0}^2{{\mathrm{<figure-callout\; id="0"\; label="B"\; filenames="Y20052004990700122.png"\; state="\{\{state\}\}">B</figure-callout>}}_0}^2}{m(R+r)}\&CenterDot;\stackrel{\mathrm{\&rho;}}{V}=-K\stackrel{\mathrm{\&rho;}}{V}=-K{\stackrel{\mathrm{\&rho;}}{V}}_0{e}^{-Kt/m}---\left(6\right)$

By (5) and (6) formula as can be known, be loaded with motion slide block and the acting force between metal guide rail and the magnetic induction density B of magnet of magnet ₀, magnet width L ₀, the quality of conductivity, slide block of metal and magnet movement velocity all relevant.

By the formula (5) of front as can be known,, data are obtained the k value by formula (5), just can obtain acceleration and the damping force of any time as long as on a plurality of points, record the instantaneous velocity of slide block and arrive time of this point.By changing the number of magnet, can adjust the size of equivalent internal resistance r, with the proper strength of control action power.Fig. 5 is the data that record with experiment instrument and by the result of (5) formula match.Related coefficient reaches 0.99985, and is consistent with the formula of theoretical derivation.Fig. 6 be by the k of match and the V that records by

The non-magnetic conductor that obtains and the relation of speed.Because the quantitative Analysis of (r+R) value is quite loaded down with trivial details in the air track, considers that magnet (is the magnetic induction density B of guide rail surface to the distance of guide rail surface ₀), the slide block mass M, the yardstick W of magnet ₀, L ₀All determine with guide rail size etc., can be by the k value that records by (R+r)=k/B ₀ ²L ₀ ²(r+R) value that is difficult to quantitative Analysis is carried out quantitative estimation.

Fig. 4, Fig. 5 are the structural drawing of the utility model embodiment 2, embodiment 2 is not to be arranged on the slide block 2 with the different magnets 3 that are of embodiment 1, but be arranged on the sliding channel of slide block 2, and as far as possible near slide block 2, the experimental principle of this embodiment is the same with embodiment 1, but,, in air track, produce induction current among the embodiment 1 like that and be unlike in so be in slide block, to produce induction current because relative motion at this moment occurs between slide block and magnet.Its interaction force also only exists when slide block process magnet.

Claims (9)

1, the experimental provision of a kind of magnet and nonmagnetic conduct or interreaction, it is characterized in that: comprise the nonmagnetic metal air track, the passage of nonmagnetic metal air track is provided with a plurality of photogate, the nonmagnetic metal air track is provided with the nonmagnetic metal slide block, the nonmagnetic metal slide block is provided with magnet, the top of nonmagnetic metal slide block is provided with light barrier, and the single-chip microcomputer treatment circuit is received in the output of photogate.

2, the experimental provision of magnet according to claim 1 and nonmagnetic conduct or interreaction is characterized in that: described magnet is a permanent magnet.

3, the experimental provision of magnet according to claim 1 and nonmagnetic conduct or interreaction is characterized in that: the cross section of described nonmagnetic metal air track is a triangle, and described slide block is a herringbone, and the both sides of slide block are equipped with magnet.

4, the experimental provision of magnet according to claim 1 and nonmagnetic conduct or interreaction is characterized in that: the spacing of described photogate is arbitrarily.

5, the experimental provision of magnet according to claim 1 and nonmagnetic conduct or interreaction is characterized in that: the spacing of described photogate equates.

6, the experimental provision of magnet according to claim 1 and nonmagnetic conduct or interreaction, it is characterized in that: described single-chip microcomputer treatment circuit is made up of multiselect one analog switch, CPU, display module, storer, expansion I/O module, keyboard, the output of multiselect one analog switch input termination photogate, CPU links to each other with output terminal, display module, storer, expansion I/O module, the keyboard of multiselect one analog switch respectively.

7, the experimental provision of a kind of magnet and nonmagnetic conduct or interreaction, it is characterized in that: comprise the nonmagnetic metal air track, the passage of nonmagnetic metal air track is provided with a plurality of photogate, the single-chip microcomputer treatment circuit is received in the output of photogate, the nonmagnetic metal air track is provided with the nonmagnetic metal slide block, the top of nonmagnetic metal slide block is provided with light barrier, is provided with at least one magnet on the path of slide block.

8, the experimental provision of magnet according to claim 7 and nonmagnetic conduct or interreaction, it is characterized in that: described single-chip microcomputer treatment circuit is made up of multiselect one analog switch, CPU, display module, storer, expansion I/O module, keyboard, the output of multiselect one analog switch input termination photogate, CPU links to each other with output terminal, display module, storer, expansion I/O module, the keyboard of multiselect one analog switch respectively.

9, the experimental provision of magnet according to claim 7 and nonmagnetic conduct or interreaction is characterized in that: described magnet is a permanent magnet.

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