CN106887179A - The electricity demonstration device of differential amplification - Google Patents

Abstract

The electricity demonstration device of differential amplification, belong to instruments used for education demonstration field, by multi-harmonic-oscillations unit, push button electronic switch, instrument connection, differential motion amplifying unit, tandem partial pressure unit, display system, restart unit, voice unit is collectively constituted, tested element is inserted in instrument connection, there are frequency and the voltage without frequency by the selection multi-harmonic-oscillations unit output of push button electronic switch, by after the amplification of differential motion amplifying unit, start tandem partial pressure unit, display system is formed to be shown and sound instruction with three kinds of light of voice unit, the effect for restarting unit is when without detected element, termination unit in display system is allowed to terminate positive feedback, recover original state, for demonstration next time is prepared, the present invention is exactly the active important document using a kind of triode as unit, the logical relation of various functions can be constituted, so as to expand the thinking of student.

Description

The electricity demonstration device of differential amplification

Technical field

Belong to instruments used for education demonstration field.

Background technology

Innovation is the soul of nationality, and young student are the strength of innovation.

The prosperity of country is talent, and the culture of talent is to educate.The emphasis teenager of education, juvenile Qiang Ze Guoqiang, the progressive then state progress of teenager, will cultivate teenager and science is had deep love for, it is crucial to improve the quality of teaching, and laboratory apparatus is precisely a key factor for improving teaching, laboratory apparatus is good, the experiment done more convincingness, so that students ' understanding things, understand natural phenomena, inspire the thinking of student, played an important role to improving level of education.Therefore, the various laboratory apparatus in teaching are all constantly being lifted, but also there are many weak points：One is the species deficiency of laboratory apparatus, and the laboratory apparatus especially for the students of the junior years is not also comprehensive.Two be the spirit taught through lively activities in instruments used for education not enough, three is the cost village school too high thus remote to some of majority instruments used for education now, can't spread to many universal instruments used for education.

Electricity is most important a kind of class in physics, full of magical Experiments of Electricity, the interest of teenager can be excited, play the role of to the basic conception for setting up electricity simultaneously important, if a kind of outstanding hookup can be developed, and this hookup can visualize electricity part concept and law by abstract, it is clear that there is positive help to educatee.If this circuit can turn into the self-control hookup of beginner again, will undoubtedly there is positive meaning to the quality-oriented education for lifting student.

But design a kind of a kind of self-control hookup that can turn into beginner again simultaneously with circuit of demonstration instrument and there is difficult point, one is from demonstrating effect, because the concept in electricity is a lot, it is to make the demonstration in terms of that, two is that this instrument is drafted primarily directed to electric capacity, inductance etc. has the element being closely connected to make the demonstration of physical property with frequency, and to make the demonstration of that several respect, its physical could sufficiently be shown, three are, especially it is important that, although some circuits can reach demonstration purpose, but a kind of outstanding self-control experimental circuit can not be turned into, because a kind of outstanding self-control experimental circuit move back relate to each unit experiment theme be suitable for beginner, move back simultaneously and relate to the interest of beginner, and whether success easy to install etc. series of problems, so this kind of outstanding circuit must also enrich, innovation, development.

The present invention is exactly, using a kind of triode as a kind of substantially active part, as the active important document of unit, the logical relation of various functions can be constituted, so as to expand the thinking of student.

The content of the invention

The present invention is the active important document using triode as unit, the logical relation of various functions can be constituted, as a kind of outstanding circuit, its purpose one is that the circuit can turn into a kind of electricity demonstration device of differential amplification, can emphatically understand resistance element structure by the demonstration of this demonstration device to be contacted with the close of frequency, and then understand the meaning of capacitive reactance and induction reactance, so as to allow beginner to lay certain electricity basis, this demonstration device can turn into a kind of instrument in the popularization of vast school.Two is the instrument because of three kinds of displays of color with light with sound, therefore with certain interest, can cultivate numerous teenagers and science is had deep love for.Three is to turn into a kind of outstanding making experimental line, and the circuit has various features, thus is conducive to making, and the basic quality to improving student has positive role.

The measure for being used is：

1st, by multi-harmonic-oscillations unit, push button electronic switch, instrument connection, differential motion amplifying unit, tandem partial pressure unit, display system restarts unit to the electricity demonstration device of differential amplification, and voice unit is collectively constituted.

Wherein：Multi-harmonic-oscillations unit is made up of two oscillating tubes, the collector resistance of two oscillating tubes, the base resistance of two oscillating tubes, cross capacitance, isolation resistance, isolated tube earth resistance, isolated tube：Partial pressure connects a collector resistance between two colelctor electrodes and power supply of oscillating tube, a base resistance is connect respectively between the base stage and power supply of two oscillating tubes, vibrate the colelctor electrode of a pipe and the indirect cross capacitance one of the base stage of two pipes of vibration, vibrate the colelctor electrode of two pipes and the indirect cross capacitance two of the base stage of one pipe of vibration, the grounded emitter line of each oscillating tube, the colelctor electrode for vibrating two pipes connects isolation resistance to the base stage of isolated tube, the emitter stage of isolated tube and the indirect isolated tube earth resistance of ground wire, the emitter stage of isolated tube is the output of multi-harmonic-oscillations unit, connect instrument connection one.

Push button electronic switch is by three switching tubes, the collector resistance of each switching tube, two state instructions, two steering diodes, two boot-strap resistors, two crossover resistances, button switch, the earth resistance of three pipes of switch, three pipe base resistances of switch, switch clamp diode compositions：The colelctor electrode of each switching tube and an indirect collector resistance of power supply, switch the colelctor electrode of a pipe and the indirect crossover resistance one of the base stage of two pipes of switch；Switch the colelctor electrode of two pipes and the indirect crossover resistance two of the base stage of one pipe of switch；A state instruction is connect respectively between the colelctor electrode and power supply of two pipes of the pipe of switch one and switch,One termination power of button switch,Base stage of the base resistance of another termination switching tube three of button switch to three pipes of switch,The earth resistance for switching three pipes is connected between the base stage of three pipes of switch and ground wire,The colelctor electrode for switching three pipes connects two guiding electric capacity,The other end for guiding electric capacity one is two-way,Boot-strap resistor one to the colelctor electrode of one pipe of switch is connect all the way,The indirect steering diode one of the base stage of one pipe of another road and switch,The other end for guiding electric capacity two is two-way,Boot-strap resistor two to two pipe collectors of switch is connect all the way,Another road and the indirect steering diode two for switching two pipe base stages,The colelctor electrode for switching two pipes is the output of push button electronic switch,Connect the negative pole of switch clamp diode,The positive pole for switching clamp diode connects the base stage of two pipes of vibration.

Differential motion amplifying unit balances triode by two differential pipes, the collector resistance and base resistance of two differential pipes, emitter resistance, balance voltage-stabiliser tube, balances triode earth resistance, differential two pipes earth resistance composition：The base resistance of a differential pipe is connected between the base stage of instrument connection two and differential two pipe, a collector resistance is connect respectively between two colelctor electrodes and power supply of differential pipe, the base resistance of differential two pipe is connected between the base stage of power supply and differential two pipe, differential two pipes earth resistance is connected between the base stage of differential two pipe and ground wire, the emitter stage of two differential pipes is connected, sending and receiving are penetrated with electrode resistance to ground wire, the colelctor electrode of differential two pipe connects balance voltage-stabiliser tube to the base stage of balance triode, balance triode earth resistance is connected between the emitter stage of balance triode and ground wire, balance the grounded collector line of triode, the colelctor electrode for balancing triode connects power supply, the transmitting for balancing triode is the output of differential motion amplifying unit with pole.

Tandem partial pressure unit by penetrate with circuit, Multilevel partial-pressure, partial pressure partially, collectively constitute.

Penetrate with circuit by penetrating with managing, penetrate with pipe base resistance one, penetrate and constituted with pipe base resistance two：Penetrate with pipe base resistance one and penetrate between the base stage for being connected on the output of differential motion amplifying unit and penetrating with pipe with pipe base resistance two, penetrate and connect power supply with the colelctor electrode of pipe, penetrate the input that the first partial pressure level is connect with the emitter stage of pipe.

Each partial pressure level is by inclined voltage-stabiliser tube in partial pressure, excitation triggering resistance, exciter tube composition, inclined voltage-stabiliser tube series connection in each partial pressure, its series connection point is partial pressure output point, connect an excitation triggering resistance to the base stage of exciter tube, the grounded emitter line of each exciter tube, the colelctor electrode of each exciter tube connects a ground terminal for display unit in display system, and inclined voltage-stabiliser tube is biased to ground wire under connecing partial pressure in last partial pressure.

Display system is made up of termination unit with multiple display units；Each display unit is constituted by the base resistance of three display tubes, three luminous instructions, three commissure electric capacity, three display tubes.

A luminous instruction is connect between three colelctor electrodes and power supply of display tube respectively, the base stage of each display tube and an indirect base resistance of power supply, the emitter stage of each display tube is connected on the colelctor electrode of exciter tube, show the colelctor electrode of a pipe and the indirect commissure electric capacity one of the base stage of two pipes of display, the colelctor electrode of two pipes and the indirect commissure electric capacity two of the base stage of three pipes of display are shown, the colelctor electrode of three pipes and the indirect commissure electric capacity three of the base stage of one pipe of display is shown.

Termination unit is made up of the P pipes that terminate, termination N pipes, commissure resistance one, commissure resistance two, termination N pipe collectors resistance, termination boot leg, termination clamp diode, the first display unit isolating diode, last display unit isolating diode：The colelctor electrode of the pipe of display three of last display unit connects termination boot leg to the base stage of termination P pipes, and the transmitting of the P pipes that terminate connects power supply with pole, the indirect commissure resistance one of the colelctor electrode of the P pipes that terminate and the base stage of termination N pipes, the grounded emitter line of the N pipes that terminate.

Termination N pipe collector resistance is connected on power supply, the colelctor electrode of N pipes that terminates and the indirect commissure resistance two of the base stage of termination P pipes, termination clamp diode, the first display unit isolating diode, the negative pole of last display unit isolating diode are all connected on the colelctor electrode of termination N pipes, the positive pole of termination clamp diode connects to be penetrated with the base stage of pipe, the positive pole of the first display unit isolating diode connects the colelctor electrode of the first exciter tube, and the positive pole of last display unit isolating diode connects the colelctor electrode of last exciter tube.

By common-anode luminous tube, positive electricity resistance is constituted together for each luminous instruction：First negative electrode of common-anode luminous tube connects a colelctor electrode for display tube, in each display unit the second negative electrode of common-anode luminous tube connect termination N pipes colelctor electrode.

Unit is restarted by restarting pipe, restarting pipe collector resistance, restart pipe triggering resistance, restart output diode and constitute：The end for restarting pipe triggering resistance is connected on and penetrates with pipe base resistance one and the middle series connection point for penetrating with pipe base resistance two, another termination for restarting pipe triggering resistance restarts the base stage of pipe, restart the grounded emitter line of pipe, restart pipe collector resistance be connected on power supply and restart pipe colelctor electrode between, restart pipe colelctor electrode connect restart output diode to termination P pipes base stage.

Voice unit is made up of multiple acoustical generators with acoustical generator protective resistance：Acoustical generator and acoustical generator protective resistance are connected between power supply and the pipe collector of display three of each display unit.

2nd, balance voltage-stabiliser tube is formed by a voltage-stabiliser tube and Diode series.

3rd, three switching tubes, two oscillating tubes, isolated tubes, penetrate and all use NPN triode with pipe, exciter tube, two differential pipes, balance triode, display tubes.

4th, two pipe base resistances of vibration are in series by adjustable resistance and fixed resistance.

5th, formed by inclined resistant series under inclined voltage-stabiliser tube under partial pressure and partial pressure partially under partial pressure.

Meaning interpretation to above-mentioned measure is as follows：

First, the principle produced by whole circuit.

The present invention is, as active part, to constitute digital circuit with triode, with two kinds of base units of logic circuit, then by these base units, devises multiple independent logic units, has then been designed to the system of entirety by logic unit again.It is so as to become a kind of outstanding electricity demonstration device and a kind of with the outstanding circuit for inspiring study thinking.

It is as a kind of outstanding its principle of electricity demonstration device.

When the frequency element surveyed（That is electric capacity, inductance）When being connected in instrument connection two ends, the electric current that multi-harmonic-oscillations unit is produced is by after the frequency element surveyed, enter into differential amplifier circuit, it is exaggerated, the output drive of circuit tandem partial pressure unit, the unit has multiple partial pressure output points, the voltage of each output point output is decrement states, each partial pressure output point of tandem partial pressure unit is connected to excitation triggering resistance to exciter tube, the colelctor electrode of each exciter tube connects a ground terminal for display unit, when without exciter tube base stage no-voltage, encloses corresponding display unit.So as to display unit does not work.When the threshold voltage more than exciter tube, exciter tube conducting, current collection extremely low level, so that the passage over the ground of correspondence display unit, start working, due to tandem partial pressure unit output point high near the voltage of signal source end, later, successively decrease decline, so the output signal of differential amplifier circuit is stronger, it is more more than the output point of driver door, the driver for having a high position of output is more, thus institute's excitation display unit is more.The role of such that it is able to clearly demonstrate out, circuit parameter element, in circuit.

For demonstrating effect is abundant, this measure notice it is following some：

One is, multi-resonant oscillating circuit can turn into tool frequency pulse power form, again can as frequency be zero be direct current form, with two kinds of different power supplys, the understanding to frequency part can be promoted.Because two kinds of power supplys will produce very different effect to frequency element.And the conversion of two kinds of power supplys is performed by push button electronic switch, so with various advantages.

Two is the increased frequency-adjustable in multi-resonant oscillating circuit unit, can further look at influence of the frequency height to element.

Three is in amplifying circuit, to employ differential amplifying triode amplifying circuit, and its benefit is good stability, while under the cooperation of adjunct circuit, it is possible to achieve the output without quiescent point, when being input no signal, and output end no signal.

Four is that light and sound effective value are employed on demonstrating effect.

Five is on light shows, to devise termination unit, and restarts unit, therefore luminous tube is glittering two kinds of big rule trends, and entertaining is full of in demonstration.

In the design as the outstanding circuit made, one is to highlight the understanding to transistor, because all units are made up of triode.Two is relatively independent each unit, and each unit contact science, debugging is simple, substantially once filling into.Three is have certain interest when each unit is checked, is conducive to exciting the learning enthusiasm of youth, it is to avoid produce tired, tired situation about doing at above-mentioned 3 points.

2nd, explanation in multi-harmonic-oscillations unit.

Multi-harmonic-oscillations unit is by two oscillating tubes（In Fig. 1 2.1,2.2）, two oscillating tubes collector resistance（In Fig. 1 2.11,2.21）, two oscillating tubes base resistance（In Fig. 1 2.12,2.22）, two cross capacitances（In Fig. 1 2.13,2.23）, isolation resistance（In Fig. 1 2.32）, isolated tube earth resistance（In Fig. 1 2.31）, isolated tube（In Fig. 1 2.3）Composition.

The oscillation principle of formation is：The characteristics of circuit is to form phase inverter with two oscillating tubes, be mutually connected cross capacitance with the colelctor electrode of other side in this grade of base stage and form.Forming the principle of vibration is：After power supply is opened,When a certain pipe collector is for a high position,Charged to other side's base stage by cross capacitance,Make to obtain bigger base flow to square tube base stage,Thus accelerate to change to saturation trend,The logical collector voltage reduction of the triode of saturation Long-term change trend simultaneously,The signal that saturation feeds back low level is transmitted to other side's triode by cross capacitance,Strong positive feedback promotes the blanking tube for changing to cut-off direction originally to tend to cut-off again,Blanking tube makes saturation pipe more saturation by cross capacitance in turn,Strong positive feedback completes the preceding half period of vibration for the first time,After cross capacitance charges to be finished,Former saturation pipe will change to exit axis,Thus the cross capacitance of two pipes transmits saturation and pick-off signal again,Form the feedback change procedure of first half cycle identical,Simply the state change of two pipes is different from first half cycle,The saturation pipe of first half cycle switchs to cut-off,Blanking tube is changed into saturation,Such principle produces second cycle,Third time cycle --- --- etc..

In foregoing circuit simple in circuits, to the less demanding of triode, the frequency required by the person of setting easily is adjusted to very much, and is matched with whole circuit.It is a kind of outstanding circuit.

In this circuit, this unit vibrates two pipe collector resistance for fixed resistance is collectively constituted with adjustable resistance two parts, with cross capacitance altogether into the time constant for constituting vibration, fixed resistance therein is a kind of range constraint to adjustable resistance, will not produce excessive the mismatch with cross capacitance of resistance deviation and produce the situation of failure of oscillation.Also two routes of pipe line imbalance difference will not be produced excessive and the situation of failure of oscillation.Such adjustment method, although generation is not impartial square wave, but is met the requirements, because this circuit does not require the square wave of equalization, but the benefit for obtaining is not use gang potentiometer, is conducive to production, is conducive to experiment.

3rd, the explanation of push button electronic switch.

Push button electronic switch is by three switching tubes（In Fig. 1 1.1,1.2,1.3）, the collector resistance of each switching tube, two state instructions, two steering diodes（In Fig. 1 1.16,1.26）, two boot-strap resistors（In Fig. 1 1.15,1.25）, two crossover resistances（In Fig. 1 1.13,1.23）, button switch（In Fig. 1 1.0）, switch three pipes earth resistance（In Fig. 1 1.39）, switch clamp diode（In Fig. 1 1.8）Composition.

Its main purpose is the working condition for controlling multi-resonant oscillating circuit unit, and turning into multi-resonant oscillating circuit unit has the test source of frequency, or as the dc source that frequency is zero, allows beholder to understand resistance element in the case of both power supplys, physical phenomenon.So as to disclose the relation of resistance element and frequency.

Switch is to the control logic of multi-harmonic-oscillations unit, the output end logic control end of two pipes is switched, by switching clamp diode（In Fig. 1 1.8）Negative pole is connected to two pipes of vibration（In Fig. 1 2.2）Base stage, when switch output end for it is high-order when, switch clamp diode is back biased, on connected part without influence, oscillator normal work.So being output as the pulse power of frequency, when the current collection extremely low level of the pipe of electric switch two, the switch clamp diode for being connected is forward bias, thus make the pipe base stage of vibration two for low level, current collection is extremely high-order, isolated tube conducting, output end output is high-order, is direct current.

Electronic switch possesses three characteristics, and one is that with output end under the cooperation of button, can export high signal, can also export low level signal, two be before a kind of self-sustaining of output signal energy arrives to the new signal of next push-botton operation with self-sustaining characteristic.Three is logic reliability.Increase state instruction simultaneously easy.

The principle of formation is, the pipe of switch one and a kind of switch two pipes connecting into for positive-feedback circuit by crossover resistance, if being that one pipe collector of switch is height, it is low to switch two pipe collectors, if instead one pipe collector of switch is low, then it is height to switch two pipe collectors.Wherein crossover resistance has played important buffer action, is, when signal is added in the input for switching a pipe, not influenceed by two pipe collectors of switch.It is state guiding triode to switch three pipes, when the transistor collector is high, can form charge circuit with low level colelctor electrode by guiding electric capacity boot-strap resistor.

When being powered, if the current collection of two pipes of switch is extremely high-order, when button switch is not pressed, push contact without connection power supply, and switchs the input of three pipes because being connected to earth resistance so being low level to disconnect.So the current collection of three pipes of switch is extremely high-order, now the colelctor electrode with guiding electric capacity one, boot-strap resistor one, one pipe of switch is formed charge circuit by its colelctor electrode.And form open circuit with the colelctor electrode of guiding electric capacity two, boot-strap resistor two, two pipes of switch.When push contact is to close, it is high-order, its current collection extremely low level to switch the input of three pipes, and guiding electric capacity one is because being unable to its negative pole of transition as negative pressure state.By the transmission of steering diode one, one pipe input of switch is negative, so that it is a high position to switch two pipe collectors, realizes upset.

When button normally opened contact is again off, the high-order colelctor electrode and the colelctor electrode of guiding electric capacity two, boot-strap resistor two, two pipes of switch for switching three pipes form charge circuit.And form open circuit with the colelctor electrode of guiding electric capacity one, boot-strap resistor one, one pipe of switch.When push-button contact is for closure, three pipe collectors of switch are low level, and guiding electric capacity two is because being unable to its negative pole of transition as negative pressure state.By the transmission of steering diode two.It is low to switch two pipe inputs, so that it is a high position to switch two pipe collectors, upset is realized again；Later inversion principle is the same.

Using mainly there is benefit following prominent after electronic switch, one is that button switch is that one kind touches button, while also allowing for installment state instruction.It is overall high-grade, benefit from, two is that button switch does not produce fly line in production, directly can produce and contact with printed panel, thus can be further ensured that product quality.Three is that button belongs to a kind of common components, it is easy to bought.

4th, the explanation on differential amplifier circuit.

Differential motion amplifying unit is by two differential pipes（In Fig. 1 5.1,5.2）, the collector resistance of two differential pipes（In Fig. 1 5.12,5.22）And base resistance（In Fig. 1 5.11 and 5.21）, emitter resistance（In Fig. 1 5.13）, balance voltage-stabiliser tube（In Fig. 1 5.32）, balance triode（In Fig. 1 5.3）, balance triode earth resistance（In Fig. 1 5.33）, differential two pipes earth resistance（In Fig. 1 5.23）Composition.

The main purpose of the circuit is that the voltage of multi-harmonic-oscillations unit can produce the situation of voltage decline after frequency element is testing capacitor, inductance（Because there is a capacitive reactance, or induction reactance pressure drop）, by after differential amplifier circuit, energy has been lifted, thus it is more macroscopical display effect.

The circuit must have a characteristics of two weights, and one is that, with good amplification characteristic, two when being the input no signal of differential amplifier circuit, exports no signal, is that output does not produce additional static current potential.

The principle of formation is, differential two pipe is because with the presence of biasing circuit, have emitter current, and connected together with the emitter stage of differential two pipe because of a differential pipe, voltage is equal, institute forms reverse bias to a differential pipe, when a differential pipe has input, for a differential pipe, produce forward bias, reflecting bias are produced for differential two pipe, so its collector voltage is raised, the voltage amplification with mutually output is produced.The letter balance triode of this grade forms balancing circuitry with balance voltage-stabiliser tube, balance voltage-stabiliser tube earth resistance, because when a differential pipe is without input, the colelctor electrode of differential two pipe has less voltage output, so the base series of balance triode have balance voltage-stabiliser tube to offset, the input signal for making its balance triode is zero.The biasing circuit that differential two pipes base stage is connected has two effects, and one is the common-mode signal that reverse bias is produced to a differential pipe, and two can be that the output voltage signal of differential two pipe is finely adjusted, and the numerical value with balance voltage-stabiliser tube is equal.

The benefit one of this grade of differential amplification of use is, because there is common-mode signal, the triode stable performance for using, so circuit stabilization.Two is that energy equal to AC/DC amplifies, and improves amplification performance, and three are turned into mutually output, after devising biasing circuit, are easy to be matched with balancing circuitry.Four be this outstanding circuit as other element circuits, by NPN type triode constitute, unified active part.

5th, the explanation of tandem partial pressure unit.

Tandem partial pressure unit by penetrate with circuit, Multilevel partial-pressure, partial pressure partially, collectively constitute.

Each partial pressure level is by inclined voltage-stabiliser tube in partial pressure, excitation triggering resistance, exciter tube composition, inclined voltage-stabiliser tube series connection in each partial pressure, its series connection point is partial pressure output point, connect an excitation triggering resistance to the base stage of exciter tube, the grounded emitter line of each exciter tube, the colelctor electrode of each exciter tube connects a ground terminal for display unit in display system, and inclined voltage-stabiliser tube is biased to ground wire under connecing partial pressure in last partial pressure.

Line feature is that voltage-stabiliser tube parameter quite, there is multiple partial pressure output points partially by the partial pressure that uses, is formed by inclined resistance under inclined voltage-stabiliser tube series connection partial pressure under partial pressure partially under partial pressure, and inclined resistance is used as current-limiting resistance under partial pressure.Because the parameter of inclined voltage-stabiliser tube is equal in each partial pressure, so as to from input to earth terminal, form the output of the stepped-up voltage of voltage.When input terminal voltage is high, then the quantity of inclined voltage-stabiliser tube is more in the partial pressure that can puncture.Then there is the output point of high-order output many, when the output voltage of each output point, during higher than connected exciter tube door, the pipe is changed into saturation, and paired display unit is energized, so as to display occur.

6th, the light display explanation of display system.

Display system is made up of termination unit with multiple display units；Each display unit is constituted by the base resistance of three display tubes, three luminous instructions, three commissure electric capacity, three display tubes.

Because this level is multiple display unit compositions.The bright state feature of luminous instruction is in display unit：As continuous-flow type.It is luminous to indicate bright to be innervation.Signal is stronger, and shown unit is more, and luminous instruction is bright must be more remote, and its whole night is that abstract electric current is likened into current.

The line construction of each display unit is the same.So only with one of display unit explanation.

At steady state, specific the first bright rule of luminous instruction is：After circuit stability, in display unit before this first it is luminous indicate it is bright, second and third, luminous instruction put out, be afterwards second it is luminous indicate bright, first and third luminous instruction is put out.Third for the 3rd luminous instruction is bright, first and second luminous instruction is put out.Then circulate.Second rule is, after last display tube of last display unit starts, all of luminous instruction is all changed into second color, while carrying out the circulation of flashing of flowing water shape by the rule of the third color, this rule will last till the beginning of demonstration next time.

Its reason is：During the tandem partial pressure unit output point no-voltage of prime, exciter tube does not start, and display unit is without ground line passage, so luminous indicate not working.

When the output point of the bleeder circuit of prime tandem partial pressure unit is into a high position, the excitation pipe collector for being connected is low, and ground wire and the system ground wire of display unit are connected, so display unit turns into working condition, first turn into transition state, then the glittering state as stable state.

Forming the first glittering reason is：Because interior three display tube of display unit, it is inconsistent due to parameter on startup, so saturation has successively other, if the colelctor electrode for showing a pipe is first saturation, the luminous instruction of the group institute band is bright, due to now showing that the voltage of commissure electric capacity one between two pipes of a pipe collector and display is unable to transition, shows two pipe base stages into negative pressure, output end is a high position, and institute's band is luminous to be designated as putting out.Show two pipe base resistances to the charging of commissure electric capacity one, when voltage exceedes two pipe base voltage of display, show that two pipe collectors are low level, show that the luminous instruction of two pipe institute bands is bright, show that the voltage of the commissure electric capacity two between three pipe base stages of two pipe collectors and display is unable to transition, three pipe base stages into negative pressure are shown, output end is a high position, institute's band is luminous to be designated as putting out.Now show three pipe base resistances to the charging of commissure electric capacity two, when voltage exceedes three pipe base stage threshold voltage of display, show that three pipe collectors are low level, show that the luminous instruction of three pipe institute bands is bright, due to now showing that the voltage of commissure electric capacity three between one pipe base stage of three pipe collectors and display is unable to transition, a pipe base stage into negative pressure is shown, output end is a high position, institute's band is luminous to be designated as putting out.A pipe base resistance is now shown to the charging of commissure electric capacity three, to after threshold voltage, one pipe collector of display is low, and the luminous instruction of institute's band is bright again, as circulation.

The reason for producing second rule be：If all display units are all bright, when last display tube of last unit is bright, the termination P pipes of termination unit（In Fig. 2 10.1）Because termination boot leg（In Fig. 2 10.7）Zero signal is introduced, so being in forward bias, the pipe collector output current is managed with termination N（In Fig. 2 10.2）As positive feedback, termination N pipe collectors are low, produce three kinds of effects, and a kind of effect is by the clamp diode that terminates（In Fig. 2 10.8）The clamper input of tandem partial pressure unit, makes all output ends of tandem partial pressure unit without output, and two be the second negative electrode for being connected to common-anode luminous tube in all luminous instructions, so all luminous instructions are changed into second color.Three is the ground wire that each display unit has been connected by the isolating diode of each display unit, each display unit ground wire by termination N pipe collectors ground connection, so each display unit is still flashed by the rule of flowing water, but now flash with former difference, because when flashing, it is that luminous instruction the two poles of the earth are still grounded, so being by the third color variations when flashing.Because termination unit is positive feedback, next demonstration will be lasted till always.

7th, the explanation of unit is restarted.

The effect of the unit is, before making demonstration next time, allows termination unit to terminate positive feedback, recovers original state.

Its principle is, when the element demonstrated is removed from instrument connection, this restarts pipe base stage no signal, so that colelctor electrode output is high-order.The high position is delivered to the base stage of termination P pipes, and its colelctor electrode reduces the sense of current, thus causes termination N pipes base current to reduce, then the base stage of termination P pipes is caused to reduce again, therefore the unit forms positive feedback again, but result is the direction that two pipes are in cut-off, until terminating.

When instrument connection connects new element, restarting pipe base stage has new signal, and current collection extremely low level does not influence the working condition of termination unit.

8th, voice indicates explanation.

When last display tube of display unit is turned on, acoustical generator has direct current channel, so sending music.

Have the advantages that after implementation following prominent：

First, electricity is important content in physics.And for beginner, understand relatively easy to galvanic, and the influence to the electric current with frequency to circuit element can feel abstract.And the demonstration of this instrument can make the abstract concept of beginner become actual.Therefore there is positive effect to studying electricity in depth.Concrete condition have it is following some：

（1）, because this demonstrator in demonstration test power supply can be changed into the pulse power, it is also possible to be changed into direct current, it is possible to clearly demonstrate out resistance element under the switching of push button electronic switch（Such as electric capacity, or inductance）In the situation that frequency is zero（It is direct current）, it is entirely different with the physical phenomenon in the case of the pulse current with frequency.

Such as electric capacity（Electric capacity its construction is two pieces of disjunct conductive materials planes）, this special construction under DC state, is being only possible to the disposable charging in transient state ground, finally as off state（Show as display portion luminous tube transient state it is bright once, then put out entirely）.But under the pulse power of frequency, theatrical change is but there occurs, because this disjunct two sides can be smoothly through electric current.

It is a good good conductor if inductance is under DC state,（It is always bright state to show as luminous instruction, into flowing water shape, and from the beginning to the end）But in the pulse current by frequency, but under the pulse power of frequency, theatrical change is but there occurs, because this end to end wire but has resistance to electric current, its physical characteristic changes completely.（The luminous bright state for indicating to manifest part is shown as, into flowing water shape, that is, the reduction of the indication light that lights）.

（2）, multi-harmonic-oscillations unit of the present invention frequency-adjustable.Can demonstrate out that frequency is higher, the impact effect to frequency element is bigger, such as same parameters electric capacity, frequency is higher, and conduction is better,（Show as the luminous bright state for indicating to manifest part, into flowing water shape, luminous indication light increases）.

And for example same parameters inductance coil, frequency is higher, and the resistance that it is presented is bigger.（Show as the luminous bright state for indicating to manifest part, into flowing water shape, but luminous indication light reduction）.

（3）, can demonstrate out, under same voltage, electric capacity is bigger, and capacitive reactance is smaller, is smaller to the resistance of electric current, and inductance is bigger, then induction reactance is bigger, is bigger to the resistance of electric current.（Show as the luminous bright state for indicating to manifest part, into flowing water shape, luminous indication light increases）.

（4）, the main inside reason of the size that capacitive reactance is presented in electric capacity can be demonstrated out, disjunct two conducting surface in inside of such as electric capacity is bigger, then capacitive reactance is smaller, and the insulating barrier between two conducting surfaces is thicker, then capacitive reactance is smaller.（Show as the luminous bright state for indicating to manifest part, into flowing water shape, luminous indication light increases）.

（5）, the main inside reason of the size that induction reactance is presented in inductance can be demonstrated out, the diameter of such as coil is bigger, then induction reactance is bigger, otherwise induction reactance is fewer（Show as the luminous bright state for indicating to manifest part, into flowing water shape, luminous indication light increases）.

（6）, induction reactance also whether have permeability magnetic material relevant with coil, it is and relevant with the property of permeability magnetic material.

2nd, excellent performance master be now embodied in it is following some：

1st, light shows characteristic.One is.It is luminous to indicate bright to be innervation.Gradual as one kind, continuous-flow type, signal is stronger, and shown unit is more, light indicate it is bright must be more remote, two is loop cycle, cycle discoloration, be it is luminous indicate bright to after termination, new circulation can be produced, and three kinds of different color rules can be produced glittering.Three be it is glittering therefore and and it is novel, be that general circuit does not possess, demonstration when attract eyeball.

2nd, presentation process light and sound shows and deposits, and luminous indicates periodically to send transient state music in a timing when glittering.Delight effect is increased, beholder teaches through lively activities.

3rd, electronic switch operation is push button electronic switch, there is benefit following prominent, and one is that button is that one kind touches button, good hand touch.Two be often by a state transformation once, it is easy to operate.Three can be clearly show be current control state, DC state in this way, at this moment indicator lamp is a kind of color, in this way the frequency power source of pulse, again can be overall high-grade in clear Chu Ming Liao into another place's color.Four is that button switch does not produce fly line in production, directly can produce and contact with printed panel, thus can be further ensured that product quality.Five is that button belongs to a kind of common components, it is easy to bought.These advantages, also allow for hookup purchase.

4th, the quantification effect of display is good, and the range of components of demonstration is wide, circuit stabilization,.One because using differential amplification, in the absence of initial potential, as long as be prime without input signal, tandem partial pressure unit exports each output point and does not export a high position, and display unit does not show.Hereby it is ensured that display is accurate.Two is that because the differential motion amplifying unit of this instrument thus has sensitivity higher, to when capacitive reactance is larger, can also clearly show that, three is the amplifying unit has amplification in pulse condition and DC state.More flexibility.Four is have common-mode circuit in this level, and heat endurance is good.Five is that common-mode circuit biasing is flexibly adjustable, and adaptive surface is wide.

5th, the concept of resistance, insulator, electric current can be demonstrated out, is demonstrated out when the timing of voltage one, the relation between electric current and resistance.Resistance is bigger, the smaller visual effect of electric current.More basic electricity knowledge is set up with the student for making the age smaller.

6th, each elementary cell of integrated circuit composition, dependable performance, contact between constituent parts rationally, so overall circuit logic is strong, science.

3rd, because above-mentioned some reason, while this instrument of institute belongs to the popular demonstrator of primary.Adapt to wide, primary school and middle school and Popular Science Education are all well suited for, have much room the need for society.Good social benefit can be produced.

4th, this instrument is easily produced, and one because element less varieties,, to buying, plug-in unit is all very easy, and two is simple debugging, and does not need expensive instrument detection, and three is low cost for this.There is good economic benefit.

5th, circuit of the present invention is simplified, and each unit contact science, operability is very strong, therefore can be conigenous row experiment installation with heuristics, by self-control, can further improve students ' practical ability and practical level, and this has positive meaning to improving students ' quality.And the present invention there are following characteristics in self-control, thus it is very suitable for self-control.

One is each several part independence, partly can be checked for unit is powered.And each is partially filled with certain interest, such as display portion, the tube light that lighted after success is that flowing water circulates shape, and the musical sound of certain rule is presented.

Two be between each several part between connect science, failure will not be substantially produced, so completing after part debugs, so that it may complete overall work.

Three is that active part is all several basic circuits of triode, therefore is easy to beginner to the understanding of such electronic component, due to active part single varieties, is given prominence to the key points, and is conducive to beginner to learn, it is to avoid numerous and be weary of studying, or not rotten situation of grasping too much.And the basic circuit of this triode, various functions of series can be developed into level into various logic units again, thus beginner's positive thinking can be guided, imagination space is expanded, be conducive to education of improving the quality.

Brief description of the drawings

Fig. 1 is the multi-harmonic-oscillations unit in the electricity demonstration device of differential amplification, push button electronic switch, differential motion amplifying unit electronic circuitry.

In figure：1.0th, button switch；1.1st, switch one is managed；1.2nd, switch two is managed；1.3rd, switch three is managed；1.11st, the state instruction of a pipe is switched；1.12nd, the collector resistance of a pipe is switched；1.13rd, crossover resistance one；1.15th, boot-strap resistor one；1.16th, steering diode one；1.17th, electric capacity one is guided；1.21st, the state instruction of two pipes is switched；1.22nd, the collector resistance of two pipes is switched；1.23rd, crossover resistance two；1.25th, boot-strap resistor two；1.26th, steering diode two；1.27th, electric capacity two is guided；1.32nd, the collector resistance of three pipes is switched；1.33rd, three pipe base resistances are switched；1.39th, the earth resistance of three pipes is switched；1.8th, clamp diode is switched；2.1st, vibration one is managed；2.11st, a pipe collector resistance is vibrated；；2.12nd, a pipe base resistance is vibrated；2.13rd, cross capacitance one；2.2nd, vibration two is managed；2.21st, two pipe collector resistance 2.22 of vibration, two pipe base resistances of vibration；2.23rd, cross capacitance two；2.3rd, isolated tube；2.31st, isolated tube earth resistance；2.32nd, isolation resistance；3.1st, instrument connection one；3.2nd, instrument connection two；5.1st, a differential pipe；5.11st, the base resistance of differential pipe one；5.12nd, differential pipe collector resistance；5.13rd, grounded emitter resistance；5.2nd, differential two pipe；5.21st, differential two pipes base resistance；5.22nd, differential two pipe collectors resistance；5.23rd, differential two pipes earth resistance；5.3rd, triode is balanced；5.32nd, voltage-stabiliser tube is balanced；5.33rd, triode earth resistance is balanced；5.5th, the output of differential motion amplifying unit.

Fig. 2 be differential amplification electricity demonstration device in tandem bleeder circuit, display system restarts unit, the electronic circuitry of voice unit.

In figure：5.5th, the output of differential motion amplifying unit；6.0th, penetrate with pipe；6.01st, penetrate with pipe base resistance one；6.02nd, penetrate with pipe base resistance two；6.1st, one-level partial pressure；6.11st, one-level excitation triggering resistance；6.12nd, one-level exciter tube；6.2nd, two grades of partial pressures；6.N, afterbody partial pressure；6.N1, afterbody excitation triggering resistance；6.N2, afterbody exciter tube；Inclined voltage-stabiliser tube under 6.X, partial pressure；Inclined resistance under 6.Z, partial pressure；8.1st, the first display unit；8.11st, the first display unit shows a pipe；8.12nd, the first display unit shows two pipes；8.13rd, the first display unit shows three pipes；8.111st, first the first luminous instruction of display unit；8.112nd, the pipe base resistance of the first display unit one；8.113rd, the first display unit commissure electric capacity one；8.121st, first the second luminous instruction of display unit；8.122nd, the pipe base resistance of the first display unit two；8.123rd, the first display unit commissure electric capacity two；8.131st, the luminous instruction of the first display unit the 3rd；8.132nd, the pipe base resistance of the first display unit three；8.133rd, the first display unit commissure electric capacity three；9.1st, the first acoustical generator；9.11st, the first acoustical generator protective resistance；8.N, last display unit；8.N1, last display unit show a pipe；8.N2, last display unit show two pipes；8.N3, last display unit show three pipes；8.N11, last display unit first are luminous to be indicated；8.N12, last pipe base resistance of display unit one；8.N13, last display unit commissure electric capacity one；8.N21, last display unit second are luminous to be indicated；8.N22, last pipe base resistance of display unit two；8.N23, last display unit commissure electric capacity two；8.N31, last display unit the 3rd are luminous to be indicated；8.N32, last pipe base resistance of display unit three；8.N33, last display unit commissure electric capacity three；9.N, last acoustical generator；9.N1, last acoustical generator protective resistance；10.1st, termination P pipes；10.2nd, termination N pipes；10.3rd, commissure resistance one；10.6th, commissure resistance two；10.5th, terminate N pipe collector resistance；10.7th, terminate boot leg；10.8th, terminate clamp diode；10.9th, the first display unit isolating diode；10.N, last display unit isolating diode；12.1st, pipe is restarted；12.2nd, pipe collector resistance is restarted；12.3rd, pipe triggering resistance is restarted；12.5th, output diode is restarted.

Specific implementation example

Fig. 1, Fig. 2 describe a kind of mode of specific implementation jointly.

First, element is selected：By figure select active part, 2, balance voltage-stabiliser tube formed by a voltage-stabiliser tube and Diode series.Three switching tubes, two oscillating tubes, isolated tubes, penetrate with pipe, exciter tube, two differential pipes, balance triode, display tubes all using NPN triode, from 8050.Termination P pipes are PNP triode 8550.Two pipe base resistances are vibrated to be in series with fixed resistance by adjustable resistance.

2nd, weld：Multi-harmonic-oscillations unit in the electricity demonstration device of differential amplification, push button electronic switch, differential motion amplifying unit electronic circuit is connected as shown in Figure 1, tandem bleeder circuit in the electricity demonstration device of differential amplification, display system, restarts unit, and the electronic circuit of voice unit is welded as shown in Figure 2.

3rd, debug.

1st, check and scheduling multi-harmonic-oscillations unit.

A, it is grounded with frequency counter its cold end, connection one pipe collector of vibration in hot junction now, has frequency and show, is that Miswire or oscillating capacitance leak electricity if nothing.

B, with frequency counter, the colelctor electrode of connection two pipes of vibration, the adjustable resistance in regulation two pipe collector resistance of vibration, oscilloscope display waveform can change, and within the requirement of design.If incorrect, the fixed resistance resistance of the adjustable resistance series connection in two pipe collector resistance of vibration should be adjusted, its rule is bigger resistance, and frequency is slower.

2nd, check and debugging differential amplifier circuit.

With oscillograph or general-purpose table look-up, the key points at different levels of electronics amplifier section, cold end ground connection are sequentially connected with oscillograph hot junction.

A, the colelctor electrode that differential two pipe is connect with universal meter, i.e. in-phase output end, in input plus signal, its magnitude of voltage is same phase relation with the relation of input voltage, is otherwise false circuit connection, or two differential triode pin wrongs.

B, isolated tube is connect with universal meter penetrate with output, its quiescent voltage is just zero, should otherwise be debugged, and differential two pipes base resistance, its rule is that base resistance is smaller, and output voltage is higher, otherwise smaller.

Then inductively or capacitively it is connected on instrument connection with one.

C, with oscillograph or universal meter connect balance triode export, adjustment multiplication factor it is adjustable, output signal should change, and its change is bigger resistance, and signal is bigger, otherwise smaller.

D, with oscillograph or universal meter connect balance triode penetrate with output, be connected on instrument connection when with a resistance unit, and will demonstration test power supply switch in zero frequency span, adjustment multiplication factor is adjustable, and output signal should change, and its change is bigger resistance, signal is bigger, otherwise smaller.

3rd, check and debugging push button electronic switch.

With oscillograph or general-purpose table look-up.

A, use oscillograph（Or universal meter）Positive pole connecting valve one manage（In Fig. 1 1.1）Managed with switch two（In Fig. 1 1.2）Colelctor electrode, now if one pipe collector of switch is for low, then it is a high position to switch two pipe collectors, if instead one pipe collector of switch is a high position, then two pipe collector low levels are switched, otherwise, it is that the crossover resistance connection that two transistor collectors are connected with each other in switching is wrong, fails to realize positive feedback.

B, use oscillograph（Or universal meter）Positive pole connecting valve three manage（In Fig. 1 1.3）Colelctor electrode, now should be high-order, be otherwise the base earth resistance of the triode（In Fig. 1 1.39）Sealing-off, or by button switch（In Fig. 1 1.0）It is even wrong, the base stage of the pipe of switch three is become high-order.

C, use oscillograph（Or universal meter）The pipe of positive pole connecting valve two colelctor electrode, while pressing button switch, loose one's grip afterwards, now switch two pipe collector output ends and should make one-shot change low level is such as changed into from a high position, be that the polar orientation of steering diode one is even wrong if incorrect.

D, use oscillograph（Or universal meter）The pipe of positive pole connecting valve two collector output, button switch is pressed again, the collector output for now switching two pipes will again occur one-shot change, such as be changed into high-order again from low level, be that the polar orientation of steering diode two is even wrong if incorrect.

E, inspection state indicate whether correctly, often to press a button, and state instruction can occur one-shot change, are otherwise that the luminous tube polarity weldering in Miswire, or state instruction is anti-.

4th, check and debugging tandem partial pressure unit part.

On instrument connection, a testing capacitor is connected, adjust the frequency of multi-harmonic-oscillations unit, increase frequency, the partial pressure output point that now occurring has the tandem partial pressure unit output of output high-order increases.

On instrument connection, a test inductance is connected, the frequency of regulation demonstration test power supply increases frequency, and the partial pressure output point that now occurring has the tandem partial pressure unit output of output high-order is reduced.

When the output point of tandem partial pressure unit is for a high position, the excitation pipe collector that the point is connected is output as low level, is otherwise that exciter tube triggering resistance sealing-off or resistance are excessive.

5th, check and debugging sound and display system, termination unit.

A, tandem partial pressure unit output point it is high-order many when, display unit is bright must be more, if it is not, the connection of driver and display unit should be checked.

B, at steady state, display unit lights when indicating bright situation, and one bright two puts out, be before this first it is luminous indicate bright, second and third luminous instruction is put out, be afterwards second it is luminous indicate bright, first and third luminous instruction is put out.Third for the 3rd luminous instruction is bright, first and second luminous instruction is put out.Then circulate.

C, when last group of display unit last display tube starts, it is all of it is luminous indicate all to be changed into second color, while carrying out the circulation of flashing of flowing water shape by the rule of the third color, this rule will last till the beginning demonstrated next time.It is that the positive feedback of termination unit is not welded if incorrect, terminate the non-low level of N pipe collectors.

Last is luminous when indicating bright for D, each group of display unit, and acoustical generator can send musical sound.Should otherwise check acoustical generator whether sealing-off.

6th, check and debug termination unit and restart unit.

A, when last group of display unit, last is luminous when indicating bright, it is all of it is luminous indicate all to be changed into second color, while carry out the circulation of flashing of flowing water shape by the rule of the third color, this rule will last till the beginning demonstrated next time.It is that the positive feedback of termination unit is not welded if incorrect, terminate the non-low level of N pipe collectors.

B, all display units do not produce the glittering of the first color, just directly produce second color variations.Then it is termination N pipe collectors and the connected isolating diode sealing-off of display unit in the case where line is errorless, the original state of termination unit is made a mistake.

C, when demonstration element insert instrument connection after, restart pipe collector and should be low, it is incorrect, should adjust restart pipe triggering resistance.It is allowed to meet the requirements.

7th, check that the pulse power is the working condition under DC state.

The pulse power is switched under DC state with button switch, now oscillograph is shown as direct current.

On instrument connection, connect a testing capacitor, at this moment display unit occur transient state it is bright once.

On instrument connection, a test inductance is connected, at this moment display level occurs the bright situation of all units.

On instrument connection, the resistance of different resistances is connected, if resistance is smaller, bright unit is more.

Claims (5)

1. the electricity demonstration device of differential amplification, it is characterized in that：By multi-harmonic-oscillations unit, push button electronic switch, instrument connection, differential motion amplifying unit, tandem partial pressure unit, display system restarts unit, and voice unit is collectively constituted；

Wherein：Multi-harmonic-oscillations unit is made up of two oscillating tubes, the collector resistance of two oscillating tubes, the base resistance of two oscillating tubes, cross capacitance, isolation resistance, isolated tube earth resistance, isolated tube：Partial pressure connects a collector resistance between two colelctor electrodes and power supply of oscillating tube, a base resistance is connect respectively between the base stage and power supply of two oscillating tubes, vibrate the colelctor electrode of a pipe and the indirect cross capacitance one of the base stage of two pipes of vibration, vibrate the colelctor electrode of two pipes and the indirect cross capacitance two of the base stage of one pipe of vibration, the grounded emitter line of each oscillating tube, the colelctor electrode for vibrating two pipes connects isolation resistance to the base stage of isolated tube, the emitter stage of isolated tube and the indirect isolated tube earth resistance of ground wire, the emitter stage of isolated tube is the output of multi-harmonic-oscillations unit, connect instrument connection one；

Push button electronic switch is by three switching tubes, the collector resistance of each switching tube, two state instructions, two steering diodes, two boot-strap resistors, two crossover resistances, button switch, the earth resistance of three pipes of switch, three pipe base resistances of switch, switch clamp diode compositions：The colelctor electrode of each switching tube and an indirect collector resistance of power supply, switch the colelctor electrode of a pipe and the indirect crossover resistance one of the base stage of two pipes of switch；Switch the colelctor electrode of two pipes and the indirect crossover resistance two of the base stage of one pipe of switch；A state instruction is connect respectively between the colelctor electrode and power supply of two pipes of the pipe of switch one and switch,One termination power of button switch,Base stage of the base resistance of another termination switching tube three of button switch to three pipes of switch,The earth resistance for switching three pipes is connected between the base stage of three pipes of switch and ground wire,The colelctor electrode for switching three pipes connects two guiding electric capacity,The other end for guiding electric capacity one is two-way,Boot-strap resistor one to the colelctor electrode of one pipe of switch is connect all the way,The indirect steering diode one of the base stage of one pipe of another road and switch,The other end for guiding electric capacity two is two-way,Boot-strap resistor two to two pipe collectors of switch is connect all the way,Another road and the indirect steering diode two for switching two pipe base stages,The colelctor electrode for switching two pipes is the output of push button electronic switch,Connect the negative pole of switch clamp diode,The positive pole for switching clamp diode connects the base stage of two pipes of vibration；

Differential motion amplifying unit balances triode by two differential pipes, the collector resistance and base resistance of two differential pipes, emitter resistance, balance voltage-stabiliser tube, balances triode earth resistance, differential two pipes earth resistance composition：The base resistance of a differential pipe is connected between the base stage of instrument connection two and differential two pipe, a collector resistance is connect respectively between two colelctor electrodes and power supply of differential pipe, the base resistance of differential two pipe is connected between the base stage of power supply and differential two pipe, differential two pipes earth resistance is connected between the base stage of differential two pipe and ground wire, the emitter stage of two differential pipes is connected, sending and receiving are penetrated with electrode resistance to ground wire, the colelctor electrode of differential two pipe connects balance voltage-stabiliser tube to the base stage of balance triode, balance triode earth resistance is connected between the emitter stage of balance triode and ground wire, balance the grounded collector line of triode, the colelctor electrode for balancing triode connects power supply, the transmitting for balancing triode is the output of differential motion amplifying unit with pole；

Tandem partial pressure unit by penetrate with circuit, Multilevel partial-pressure, partial pressure partially, collectively constitute；

Penetrate with circuit by penetrating with managing, penetrate with pipe base resistance one, penetrate and constituted with pipe base resistance two：Penetrate with pipe base resistance one and penetrate between the base stage for being connected on the output of differential motion amplifying unit and penetrating with pipe with pipe base resistance two, penetrate and connect power supply with the colelctor electrode of pipe, penetrate the input that the first partial pressure level is connect with the emitter stage of pipe；

Each partial pressure level is by inclined voltage-stabiliser tube in partial pressure, excitation triggering resistance, exciter tube composition, inclined voltage-stabiliser tube series connection in each partial pressure, its series connection point is partial pressure output point, connect an excitation triggering resistance to the base stage of exciter tube, the grounded emitter line of each exciter tube, the colelctor electrode of each exciter tube connects a ground terminal for display unit in display system, and inclined voltage-stabiliser tube is biased to ground wire under connecing partial pressure in last partial pressure；

Display system is made up of termination unit with multiple display units；Each display unit is constituted by the base resistance of three display tubes, three luminous instructions, three commissure electric capacity, three display tubes；

A luminous instruction is connect between three colelctor electrodes and power supply of display tube respectively, the base stage of each display tube and an indirect base resistance of power supply, the emitter stage of each display tube is connected on the colelctor electrode of exciter tube, show the colelctor electrode of a pipe and the indirect commissure electric capacity one of the base stage of two pipes of display, the colelctor electrode of two pipes and the indirect commissure electric capacity two of the base stage of three pipes of display are shown, the colelctor electrode of three pipes and the indirect commissure electric capacity three of the base stage of one pipe of display is shown；

Termination unit is made up of the P pipes that terminate, termination N pipes, commissure resistance one, commissure resistance two, termination N pipe collectors resistance, termination boot leg, termination clamp diode, the first display unit isolating diode, last display unit isolating diode：The colelctor electrode of the pipe of display three of last display unit connects termination boot leg to the base stage of termination P pipes, and the transmitting of the P pipes that terminate connects power supply with pole, the indirect commissure resistance one of the colelctor electrode of the P pipes that terminate and the base stage of termination N pipes, the grounded emitter line of the N pipes that terminate；

Termination N pipe collector resistance is connected on power supply, the colelctor electrode of N pipes that terminates and the indirect commissure resistance two of the base stage of termination P pipes, termination clamp diode, the first display unit isolating diode, the negative pole of last display unit isolating diode are all connected on the colelctor electrode of termination N pipes, the positive pole of termination clamp diode connects to be penetrated with the base stage of pipe, the positive pole of the first display unit isolating diode connects the colelctor electrode of the first exciter tube, and the positive pole of last display unit isolating diode connects the colelctor electrode of last exciter tube；

By common-anode luminous tube, positive electricity resistance is constituted together for each luminous instruction：First negative electrode of common-anode luminous tube connects a colelctor electrode for display tube, in each display unit the second negative electrode of common-anode luminous tube connect termination N pipes colelctor electrode；

Unit is restarted by restarting pipe, restarting pipe collector resistance, restart pipe triggering resistance, restart output diode and constitute：The end for restarting pipe triggering resistance is connected on and penetrates with pipe base resistance one and the middle series connection point for penetrating with pipe base resistance two, another termination for restarting pipe triggering resistance restarts the base stage of pipe, restart the grounded emitter line of pipe, restart pipe collector resistance be connected on power supply and restart pipe colelctor electrode between, restart pipe colelctor electrode connect restart output diode to termination P pipes base stage；

Voice unit is made up of multiple acoustical generators with acoustical generator protective resistance：Acoustical generator and acoustical generator protective resistance are connected between power supply and the pipe collector of display three of each display unit.

2. the electricity demonstration device of differential amplification according to claim 1, it is characterized in that：Balance voltage-stabiliser tube is formed by a voltage-stabiliser tube with Diode series.

3. the electricity demonstration device of differential amplification according to claim 1, it is characterized in that：Three switching tubes, two oscillating tubes, isolated tubes, penetrate and all use NPN triode with pipe, exciter tube, two differential pipes, balance triode, display tubes.

4. the electricity demonstration device of differential amplification according to claim 1, it is characterized in that：Two pipe base resistances are vibrated to be in series with fixed resistance by adjustable resistance.

5. the electricity demonstration device of differential amplification according to claim 1, it is characterized in that：Formed with resistant series partially under partial pressure by inclined voltage-stabiliser tube under partial pressure partially under partial pressure.