CN2118336U

CN2118336U - Magnetic field demonstrating teaching apparatus

Info

Publication number: CN2118336U
Application number: CN 92213839
Authority: CN
Inventors: 朱关麟
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-05-12
Filing date: 1992-05-12
Publication date: 1992-10-07

Abstract

The utility model relates to a magnetic field demonstrating teaching apparatus which is completed on the basis of the circuit of a black-and-white TV. The utility model is characterized in that a three-phase coil and a perpendicular coil are sheathed on the neck of a picture tube; each of the two coils is wound in the axial direction on each of insulating pipe sleeve; the three windings of the three-phase coil are in the homogeneous distribution in 120 DEG; the two windings of the perpendicular coil are in the perpendicular distribution in 90 DEG; the three-phase coil and the perpendicular coil are respectively connected with the generating circuit of a three-phase rotating magnetic field and the generating circuit of a two-channel perpendicular magnetic field. The simulation and the demonstration of the rotating magnetic field and the perpendicular alternating magnetic field are completed for the first time in electrician teaching by the utility model to make the means of the electrician teaching advanced.

Description

Magnetic field demonstrating teaching apparatus

The utility model relates to a kind of instruments used for education, particularly a kind of teaching appliance of demonstrating magnetic field properties.

At present, in electromagnetics teaching, also there are not a kind of instruments used for education that can demonstrate the dynamic magnetic field characteristic, teacher can only illustrate the characteristic in magnetic field by books and wall chart when teaching, can only in laboratory, represent the distribution of static magnetic field at the most with iron powder and magnet, deepen classmates' printing, but said method is more original, and is more abstract, makes student's indigestion.In the laboratory, people's multipurpose oscilloscope is observed some voltage waveform, but the oscillograph screen is little, can't be used for classroom instruction demonstration, and main is the characteristic that it can only show dynamic electric field, then can't show the characteristic of dynamic magnetic field.

The purpose of this utility model is exactly in order to address the above problem, and a kind of magnetic field teaching demonstration instrument is provided.

Technical solution of the present utility model as shown in the figure.

Fig. 1 is the utility model three-phase coil schematic cross-section.

Fig. 2 is the utility model quadrature coil schematic cross-section.

Fig. 3 is the utility model three phase rotating field generation circuit electrical schematic diagram;

Fig. 4 is the utility model binary channels quadrature field generation circuit electrical schematic diagram.

The utility model is to finish on the basis of black and white television set circuit, it includes intermediate level circuit, video amplifier circuit, scanning circuit and the kinescope of black and white television set, and the deflection coil on the kinescope neck taken off, it is characterized in that being set with three-phase coil Za, Zb, Zc and quadrature coil X, Y at the kinescope neck of black and white television set, three-phase coil be with three winding Za, Zb, Zc along the axial direction of insulative pipe sleeve T around System, and by the cross-wise direction of insulative pipe sleeve T they are 120 degree evenly distribute (such as Fig. 1) mutually. The quadrature coil is with two winding X, the Y axial direction coiling along insulative pipe sleeve T ', and by their mutually orthogonal 90 degree distribute (such as Fig. 2) that are of the cross section of insulative pipe sleeve T '. The insulative pipe sleeve T of three-phase coil and quadrature coil and the internal diameter of T ' all match with the external diameter of tube neck of kinescope, and they connect together. Three-phase coil Za, Zb, Zc are connected with the three phase rotating field circuit for generating, and such as Fig. 3, this circuit is by three-phase alternating-current supply A, B, C and three-phase transformer B thereof₁、B ₂、B ₃With change-over switch K₁、K ₂And output transformer B₄、B ₅、B ₆Form three-phase transformer B₁、B ₂、B ₃An elementary end meets respectively three phase mains A, B, C, and their elementary other ends meet zero-power line, change-over switch K altogether₁Be double-point double-throw switch, two moving knife end 1,2 respectively with three-phase transformer B₁、B ₂Secondary connection, K₁Two groups of static break ends 3,4 and 5,6 intersect short circuits, wherein static break end 3,6 meets output transformer B₄Elementary I end, static break end 4,5 meets output transformer B₅Elementary I end, output transformer B₆Direct and the three-phase transformer B of elementary I end₃Secondary output connect change-over switch K₂Be three cuttves, three throw switches, its three moving knife ends 7,8,9 respectively with output transformer B₄、B ₅、B ₆Elementary II end connects, and in its three groups of static break ends, each is organized first

static break end

10,11,12 and connects ground connection, each organize second static break end 10 ', 11 ', 12 ' connect, each organizes the 3rd static break end 10 ", 11 ", 12 " respectively with output transformer B₅、B ₆、B ₄Elementary I end connects, B₄、B ₅、B ₆Secondary output be connected with three winding Za, Zb of three-phase coil, the two ends of Zc respectively. Quadrature coil X, Y are connected with binary channels quadrature field circuit for generating, are made up of saw-toothed wave generator, X passage amplifier and Y channel amplifier such as Fig. 4, this circuit, and saw-toothed wave generator is by transistor BG₁, unijunction transistor BG₂, voltage-stabiliser tube DW, potentiometer W, resistance R₁－R ₄And capacitor C₁Form, the X passage amplifier is by resistance R₅、R ₆, capacitor C₂、C ₃With compositing amplification tube BG₃Form, the Y channel amplifier is by resistance R₇、R ₈, capacitor C₄、C ₅With compositing amplification tube BG₄Form, the output of saw-toothed wave generator is by change-over switch K₃Be connected K with the X passage amplifier₃Be double-point double-throw switch, two moving knife end 13,14 is connected input with positive supply+Vc respectively and is connected with the X passage amplifier, in its two groups of static break ends 15,16 and 17,18, static break end 15 is connected with the power end of saw-toothed wave generator, static break end 16 is unsettled, and static break end 17 is BG with the output of saw-toothed wave generator₁Colelctor electrode connect static break end 18 and directions X external signal input socket Z₁Connect, the output of X passage amplifier is from capacitor C₃Draw the X winding that connects the quadrature coil, the input of Y channel amplifier is capacitor C₄A termination Y-direction external signal input socket Z₂, the output of Y channel amplifier is from capacitor C₅Draw the Y winding that connects the quadrature coil.

The utility model can carry out the simulation of rotating excitation field in the three phase electric machine, also can carry out the simulation of quadrature alternating magnetic field stack. The course of work such as Fig. 3 of rotating excitation field in the simulation three phase electric machine, three-phase transformer B₁、B ₂、B ₃Elementary three phase mains A, B, the C of adding respectively, this moment change-over switch K₁Moving knife end 1,2 be connected change-over switch K with its static break end 3,5 respectively₂Moving knife end 7,8,9 be connected with its

static break end

10,11,12 respectively, like this, three-phase transformer B₁、B ₂The output of secondary AC power pass through K₁、K ₂Deliver to output transformer B₄、B ₅Elementary, three-phase transformer B₃The output of secondary AC power directly deliver to output transformer B₆Elementary, at B₄、B ₅、B ₆Secondary output end obtain one and change identical alternating source with three phase mains A, B, C respectively, these three alternating sources are delivered to respectively three-phase Three winding Za of coil, Zb, on the Zc, because the interior intermediate level circuit of black and white television set this moment, video amplifier circuit and scanning circuit work, then existing electron beam emission on its kinescope, work as like this three-phase coil winding Za on the kinescope neck, Zb, when Zc connects the three-phase alternating source, will produce the alternating magnetic field of phase difference 120 degree, again because three winding Za, Zb, Zc is 120 degree spatial distributions at its insulative pipe sleeve T, Za then, Zb, three alternating magnetic fields that Zc produces are superimposed as rotating excitation field, this rotating excitation field is just so that the electron beam in the kinescope is pressed the direction rotation of rotating excitation field, when they beat on the anterior fluorescent screen of kinescope, will demonstrate the figure of this rotating excitation field, thereby finish the simulation demonstration to rotating excitation field in the three phase electric machine. As change-over switch K₁When switching, can change the direction of rotation of rotating excitation field, as change-over switch K₂During switching, can change the connection of three phase mains in the three phase electric machine, thus the different graphic of the rotating excitation field when demonstrating out different connection. Additive process such as Fig. 4 of simulation quadrature alternating magnetic field are at change-over switch K₃Moving knife end 13,14 when being connected with its static break end 15,17 respectively, the saw-toothed wave generator plugged is from BG₁Sawtooth signal of colelctor electrode output be added to the input of X passage amplifier, this signal is through multiple tube BG₃Deliver to after the amplification on the X winding of quadrature coil; At this moment, can be at the Y-direction external signal input socket Z of Y channel amplifier input₂The various alternating signals of upper access such as sine wave signal, square-wave signal, halfwave rectifier signal, damped oscillation signal etc., are supposed Z₂Upper access sine wave signal, then this signal is through multiple tube BG₄Deliver to after the amplification on the Y winding of quadrature coil, on the X of quadrature coil and Y winding, obtain respectively sawtooth current and sine-wave current like this, thereby by X and Y winding respectively generation and sawtooth waveforms and sinusoidal wavely change identical alternating magnetic field, because they are mutually orthogonal on its insulative pipe sleeve T ', the space is 90 degree and distributes, then on the electron beam of the superposition in these two kinds of magnetic fields in the kinescope, make The fluorescent screen demonstrates the figure after these two kinds of magnetic field superposition, and it is a sinusoidal waveform. If Y-direction external signal input socket Z₂Upper when inserting respectively square-wave signal, halfwave rectifier signal or damped oscillation signal, then the fluorescent screen will go out charging and discharging curve, half-wave figure or damped oscillation waveform by display respectively. Change-over switch K₃During switching, can be at the directions X external signal input socket Z of X passage amplifier in₁Various other alternating signals of upper access, thus the stack figure of more two alternating magnetic fields demonstrated out. Such as X, Y-direction external signal input socket Z₁、Z ₂Upward insert respectively different frequency and frequency ratio is the sine wave signal of ratio of integers, then can obtain lissajouf figure in the fluorescent screen, if Z₁、Z ₂The upper access respectively with out of phase sine wave signal frequently then can obtain in the fluorescent screen oval figure, can judge the phase difference of two sine wave signals with this, in special situation, i.e. and Z₁、Z ₂During the upper respectively access sine wave signal that phase phasic difference 90 is spent with frequency, then obtain a circle in the fluorescent screen, it is the simulation of rotating excitation field in the monophase machine, especially when the frequency of the sine wave signal of this two phase phasic differences 90 degree is 50HZ, the circle that then shows on the fluorescent screen can rotate, and the simulation rotating excitation field is more vivid.

The utility model has been finished simulation and the demonstration to rotating magnetic field first in electrical teaching, not only can demonstrate the rotating magnetic field in three phase electric machine and the monophase machine, also can demonstrate the magnetic field after the various alternating signal mutual superposition, and can observe the waveform of various alternating signals, the intuitive of electrical teaching content is improved greatly, students is more readily understood and accepts, teaching efficiency is remarkable.The utility model circuit is simple, and function is many, and dependable performance is with low cost, not only can be widely used in electrician's classroom instruction, also can be used for laboratory operation.

Claims

1, a kind of magnetic field teaching demonstration instrument, it includes intermediate level circuit, video amplifier circuit, sweep circuit and the kinescope of black and white television set, and the deflection coil on the kinescope neck taken off, it is characterized in that on the kinescope neck of black and white television set, being set with three-phase coil Z _a, Z _b, Z _cWith quadrature coil X, Y, three-phase coil is with three winding Z _a, Z _b, Z _cAxial direction coiling along insulative T, and they are 120 degree mutually and evenly distribute by the cross-wise direction of insulative T, quadrature coil is with two winding X, the Y axial direction coiling along insulative T ', and their mutually orthogonal 90 degree that are of cross section by insulative T ' distribute, the internal diameter of insulative T, T ' all matches with the external diameter of tube neck of kinescope, they cooperate together, three-phase coil Z _a, Z _b, Z _cWith by three-phase alternating-current supply A, B, C and three-phase transformer B thereof ₁, B ₂, B ₃With change-over switch K ₁, K ₂And output transformer B ₄, B ₅, B ₆The three phase rotating field generation circuit of forming is connected, and quadrature coil X, Y are connected with the binary channels quadrature field generation circuit of being made up of sawtooth wave electric organ, X passage amplifier and Y channel amplifier.

2, by the described magnetic field of claim 1 teaching demonstration instrument, it is characterized in that in three phase rotating field generation circuit three-phase transformer B ₁, B ₂, B ₃An elementary end meets three-phase supply A, B, C respectively, and their elementary other ends meet zero-power line, change-over switch K altogether ₁Be double-point double-throw switch, two moving knife end 1,2 respectively with three-phase transformer B ₁, B ₂Secondary connection, K ₁Two groups of static break ends 3,4 and 5,6 intersect short circuits, and wherein static break end 3,6 meets output transformer B ₄Elementary I end, static break end 4,5 meets output transformer B ₅Elementary I end, output transformer B ₆Direct and the three-phase transformer B of elementary I end ₃Secondary output connect change-over switch K ₂Be three cuttves, three throw switches, its three moving knife ends 7,8,9 respectively with output transformer B ₄, B ₅, B ₆Elementary II end connects, and in its three groups of static break ends, each is organized first static break end 10,11,12 and connects ground connection, each organize second static break end 10 ', 11 ', 12 ' connect, each organizes the 3rd static break end 10 ", 11 ", 12 " respectively with output transformer B ₅, B ₆, B ₄Elementary I end connects, B ₄, B ₅, B ₆Secondary output be connected with three winding Za, Zb of three-phase coil, the two ends of Zc respectively.

3, by the described magnetic field of claim 1 teaching demonstration instrument, it is characterized in that saw-toothed wave generator is by transistor BG in binary channels quadrature field generation circuit ₁, unijunction transistor BG ₂, stabilivolt DW, potentiometer W, resistance R ₁-R ₄And capacitor C ₁Form, the X passage amplifier is by resistance R ₅, R ₆, capacitor C ₂, C ₃With compositing amplification tube BG ₃Form, the Y channel amplifier is by resistance R ₇, R ₈, capacitor C ₄, C ₅With compositing amplification tube BG ₄Form, the output of saw-toothed wave generator is by change-over switch K ₃Be connected K with the X passage amplifier ₃Be double-point double-throw switch, two moving knife end 13,14 is connected with the X passage amplifier input terminal with positive supply+Vc respectively, in its two groups of static break ends 15,16 and 17,18, static break end 15 is connected with the power end of saw-toothed wave generator, static break end 16 is unsettled, and static break end 17 is BG with the output of saw-toothed wave generator ₁Collector connect static break end 18 and directions X external signal input socket Z ₁Connect, the output terminal of X passage amplifier is from capacitor C ₃Draw the X winding that connects quadrature coil, the input end of Y channel amplifier is a capacitor C ₄A termination Y direction external signal input socket Z ₂, the output of Y channel amplifier is from capacitor C ₅Draw the Y winding that connects quadrature coil.