Modes of self-excitation of the oscillator. Basic schemes of self-excitation modes

Soft mode.

If the operating point is located on the range of the characteristic iK (uBE) with the greatest steepness, then the self-excitation mode is called soft.

Simply change the amplitude of the strum of the first harmonic fallow according to the value of the coefficient of return links of the KOS. Change of KOS to bring to change the kuta nahila a direct swivel link (Fig. 2)

Malyunok 2. Soft mode of self-excitation

At KOS = KOS1, the generator becomes quiet and stable, and the generator does not start up, the amplitude of the oscillation reaches zero (Fig. 2 b). The value of KOS \u003d KOS2 \u003d KKR є boundary (critical) between stability and instability I will become calm. When KOS = KOS3 > KKR, the station becomes calm and unstable, the generator wakes up, and the value of Im1 is set to the same point A. When the KOS is increased, the value of the first harmonic of the outgoing stream will gradually increase and, with KOS = KOS4, it will be at point B. When the KOS is changed, the amplitude will change Well curves and colivannya zіrvutsya at coefіtsієntі zv'yazku KOS \u003d KOS2< ККР.

Like a visnovka, you can signify the following features of the soft mode of self-excitation:

for damage, it is not necessary to have a large value of the coefficient of the serum KOS;

Ø zbudzhennya that sight colivan vіdbuvayutsya with the same value of the coefficient of the zv'yazku KKR;

Ø it is possible to smoothly regulate the amplitude of stationary coliving by means of a way to change the value of the coefficient of svorotny zv'yazku KOS;

as a small trace of the great value of the post-storage collector stream, which should lead to a small value of the KKD.

Hard mode.

How the working point is located on the distance of the characteristic iK = f(uBE) with a small steepness S< SMAX, то режим самовозбуждения называется жестким.

Figure 3. Hard wake-up mode

Damage to the oscillator will be detected if the turnaround coefficient is changed to the value of KOS3 = KOSKR. Further increase in the KOS to produce a small increase in the amplitude of the first harmonic of the outgoing (collector) stream Im1 along the V-D-D path. Changing the KOS to KOS1 does not lead to the sight of the colivan, so that the points B and B are on the right, and the point A is on the right. Colivannya is seen at point A, then at KOS< КОС1, так как точка А неустойчива слева.

In this order, it is possible to recognize the following features of the operation of the generator in the hard mode of self-excitation:

for self-excitation, a large value of the coefficient of the serum zv'yazku KOS is required;

Ø zbudzhennya that vision of colivan vіdbuvayutsya stupіn often at different values ​​of the coefficient of svorotny zv'yazku KOS;

Ø the amplitude of stationary kolivans at the great boundaries cannot be changed;

Ø post_yna warehouse of the collector stream is less, lower in mild mode, also, significantly higher than KKD.

Comparing the positive and negative sides of the self-excited modes, we come to a wild winding: more self-exciting generator ensures soft mode, and economical work, high CCD and stable amplitude of coliving - hard mode.

The exercise of consolidation of the drive led to the idea of ​​automatic shifting, if the generator is energized in the soft mode of self-excitation, like a robot in the hard mode. The meaning of automatic adoption is discussed below.

Automatically reset.

The essence of the mode lies in the fact that in order to ensure the oscillator start-up in the soft mode, the position of the operating point is selected on the linear distance of the flow characteristic with the maximum steepness. Equivalent support to the contour is chosen in such a way that the mind of self-excitation is won over. In the process of increasing the amplitude of the surge, the mode of the constant stream is automatically changed and in the stationary station, the operation mode is set to the output of the outlet stream (collector stream), so that the autogenerator works in the hard mode of self-excitation at the distance of the passage through the steep curve (Fig. 4).

Figure 4. Principle of automatic oscillator adoption

The voltage of the automatic zsuva is taken off by sounding the struma of the base with a path included in the lancet of the basil of the lance R B C B (Fig. 5).

Figure 5

Pochatkova voltage shift is ensured by the voltage drop E B. When the amplitude increases, the voltage increases on the resistor R B, which creates a constant storage base stream I B0. The resulting displacement voltage (E B - I B0 R B) changes when changing, increasing EB C T.

In practical circuits, the voltage is usually used for the help of the basic dilnik R B1, R B2 (Fig. 6).

Baby 6

In this scheme, the voltage is shifted

E B.BEGINNING \u003d E K - (I D + I B0) R B2,

de I D \u003d EK / (R B1 + R B2) - strum dilnik.

When the amplitude of the increase in the amplitude of the post-storage stream of the base IB 0 increases and the value of the EBST changes according to the value reaching the value of the EBST in the mode that is restored. Capacitor SB prevents the resistor RB1 from short-circuiting in a constant stream.

The next step is to designate that the introduction of an automatic displacement into the generator circuit of the lancet generator can lead to a reversible generation phenomenon. The reason for the fault is the delay in the voltage of the automatic adjustment of the increase in the amplitude of the surge. During the great lent hour t = RBSB (Fig. 8.41), the coli will increase rapidly, and the sound will become practically invariable - EB.NACH. Farther away, the shift begins to change and may appear smaller in terms of those critical values, for which the minds of stationarity are still vibrated, and the colivanny zirvutsya. As soon as I see the colivan, the capacity of the SB will be fully discharged through RB and the adoption of a new pragmentime EB.NACH. As soon as the coolness becomes great, the generator wakes up again. Let the process be repeated. In this rank, the kolivany is periodically blamed and resurrected.

Urivchasti kolivannya, as a rule, can be seen to nebazhanyh pavilions. For this reason, it is important to carry out the analysis of the elements of the lancet of automatic displacement in such a way as to make it impossible to interrupt the interruption of frequent generation.

To turn off intermittent generation in the circuit (Fig. 4), select the value of SB from the equality

Auto-oscillator with transformer turn signal

Let's take a look at the simplified diagram of a transistor self-oscillator of harmonics from a transformer turning link (Fig. 7).

Malyunok 7. Auto-oscillator

Assignment of elements of the scheme:

transistor VT p-n-p type, vikonuє the role of a subsiluvial non-linear element;

Ø Coil circuit LKCKGE sets the frequency of the generator colivan and ensures its harmonic form, speech conductivity GE characterizes the consumption of energy in the circuit itself and in the outer drive connected to the circuit;

Ø Coil LB provides a positive return link between the collector (external) and base (input) lances, it is inductively connected to the coil circuit LK (coefficient of mutual induction M);

Ø zherela zhivlennya EB and ЄK to secure the necessary constant voltage at the transitions of the transistor to ensure the active mode of yoga robot;

Ø condenser СР distributes the generator of that yogo drive along the steady stream;

Ø blocking capacitors SB1 and SB2 shunt the lifeline of the replaceable struma, including the consumption of energy on their internal supports.

Fallow in the value of the constant voltage of life, bringing to the electrodes of the subsiluvial element, and in the coefficient K 0 . There are two possible modes of self-excitation: soft and hard.

In the mode of soft self-excitation, I work point A on the linear distance of the I–V characteristic of the subsiluvial element (Figure 9.1, a), which ensures the cob mode of the subsiluvial element without the output of the excitatory stream. The minds of self-excitation are blamed for insignificant changes in the input voltage, which are always apparent in real minds through fluctuations in the charge.

The back of the head in the autogenerator is growing rapidly. Then, through the non-linearity of the CVC of the auxiliary element, the increase in the amplitude of the surge improves, the voltage spikes at the input are consumed on the VAC sections with a smaller static steepness, and therefore to bring the average steepness to a change S porіvn that transfer coefficient Up to 0s lancers of the zvorotny zv'yazku.

Figure 9.1 - Diagrams that explain the self-excitation modes.

The increase in coliving continues until the hour when the transmission coefficient changes to one. As a result of the autogenerator, a stationary mode will be established, which will give a constant amplitude of the outward vibrations, moreover, the angle of the outward stream will be 0> 90 °. The frequency of these colivations is already close to the resonant frequency of the colivation system. Zvernemo respect: yakbi pіdsilyuvalny element mаv linear volt-ampere characteristic, the increase in the amplitude of the auto-cooling would be inexorably, which is physically impossible. Therefore, in a linear lance, it is impossible to take autocooling steps with a constant amplitude.

Due to the non-linearity of the current-voltage characteristics, the shape of the output stream of the subsiluvial element appears non-sinusoidal. However, if you add a great quality factor (Q = 50 ... 200) of the collateral system of the first harmonica of the first stream and, then, the voltage at the output of the oscillator є may be harmonic colivans.

9.5 Hard wake-up mode

In this mode, the voltage of the sound is set in such a way that, at low amplitudes of the input voltage, the strum does not pass through the power element. The same insignificant ringing, which bleeds in the contour, cannot call the strum at the exit lance, and the self-excitation of the oscillator does not come. The colivannya is blamed less for them to reach the great cob amplitude, which can always be ensured. The process of guilt and build-up of colivan under the harsh regime of self-excitation is illustrated by little 9.1, b. It can be seen that at small amplitudes of the input voltage (curve 1) the strum i vor = 0 that auto-cooking is not blamed. The stench is blamed only when reaching the great amplitude of the voltage (curve 2) and quickly increases to the value that has been restored. In the stationary mode, the subsidy element works with the cuts of the outlet strum<90°.

For the efficiency of the operation of the autogenerator, it is necessary to stop the soft mode of self-excitation, which is blamed for the same mode of cogeneration after the inclusion of the dzherel of life. However, under the harsh regime, coliving with a cut<90° обеспечиваются более высокий КПД автогенератора и меньшие тепловые потери. Поэтому в стационарном режи­ме автогенератора более выгоден имен­но режим с малыми углами отсеч­ки выходного тока усилительного эле­мента.

Let's turn back to small. 9.6 that z'yasuєmo behavior of the oscillator when changing the coefficient of the return signal. When the connection is weakened, the lines of the II grow, and at some critical value, which wraps the unevenness (9.13) on the rіvnіst vyniknennya kolivan is impossible. Line zv'yazku, vіdpovіdna critical zvorotny zv'yazok, occupies the position of OB.

Yakshcho in an autogenerator with an inductive return link, such a coil characteristic, shown in fig. 9.6 smoothly increase M, then starting from the critical value, the amplitude of the stationary coli will gradually increase, as shown in fig. 9.8. Such a mode of self-excitation is called soft. In addition to what has been said, it is necessary for the soft mode to take off, so that the kolivalna characteristic went out of the zero point and it is small to make a big hit in the region of small amplitudes. All times are counted for the hour of automatic adoption.

When vikoristannі primusovogo (zvnіshny) zmіschennya kolivalny characteristic nabuvaє viglyadu, shown in fig. 9.9. For viniknennya kolivan, at times it is necessary to have a strong link (line, mutual induction).

Rice. 9.8. Independence of stationary amplitude in the form of a whistle-blower in mild mode

Rice. 9.9. Collisional characteristic, which is suitable for hard mode

Rice. 9.10. Independence of stationary amplitude in the form of a whistle-blower in hard mode

Rice. 9.11. Up to power generation resistance in hard mode

After that, as the ringing has been established, the link can be weakened to a value, with which line the link takes the position of the OB. For a distant weakening of the zv'yazku kolivayutsya. To improve the colivane M, it is necessary to increase the value of the double line link OA. This mode of self-excitation is called

The dependence of the stationary amplitude of the wave M in the hard mode is shown in fig. 9.10, moreover, the arrows indicate the direct change of M.

Even though the pressure of the primus flooring is large, since the coli- cation characteristic does not start from zero (Fig. 9.11), then there is no increase in the return zv'yazku not zdatne volatility autocooling. As well as viklikati kolyvannya with the help of a splendid infusion, then for the sake of a strong turning point of infusion, you can buti and then pripinennya infusion. Three points of the cross line I and II point are stable, and point D is unstable (there is a dynamic stability on the edge, so the stability of the generation). Tse means that with small swing amplitudes of the strum amplitude in the contour of the point C, the system rotates at the outward station, the slopes of the amplitude in the area of ​​the point D progressively increase and transfer the amplitude either to the point C, or to the statistic cost (at static cost) . The proof of the instability of the point D is similar to the proof of the stability of the point C, pointed at the front paragraph.

Classification of generators

Generator— tse attachments that convert the energy of the dzherel postyny ​​strum into the energy of electromagnet colivans with the same parameters.

The main parameters of coliving are: amplitude, frequency and shape.

The main advantage that is presented to the generators is the stability of their work when they are injected into the new factors, which destabilize, so that the stability of the parameters of the generation of the generators.

Generators are widely zastosovuyt at tehnіtsi zv'yazku. The stench is vikorated for the formation of test signals, synchronization signals, service signals, reference signals, etc.

A smarter graphic image of generators is shown on a small 1.

Malyunok 1 - Smart graphic designation of generators: a) harmonies; b) sequence of rectilinear pulses; c) the sequence of saw-like impulses.

Classification of generators introduced little 2.

Electricalє generators, which without interruption transform the energy of the dzherel of the steady stream into the energy of the colivan.

Electromechanicalє generators, in which the frequency of coliving, which are generated, is set by the frequency of mechanical coliving of certain materials (quartz plate).

For generators internal awakenings or s self-excited kolyvannya are molded with the help of an internal power supply.

Figure 2 - Classification of generators

For generators zvnіshnіm zbudzhennyam shaping the colivan zdіysnyuєtsya z joining the yoga input of the other colivannya (multiplication of that rozpodіl frequency).

Relaxation generators or multivibrators form a ringing of non-harmonious forms (sequences of straight-cut, tri-cut, saw-like, ring-like, etc. pulses).

Harmony or quasi-harmonious generators and form colivannya harmonic form.

AT RC-generators like a viborchy lansyug, RC-filters are used.

AT LC-generators like a viborchy lansyug vikoristovuetsya parallel kolyvalny contour.

AT two-pointLC-generators the kolyvalny circuit is connected to the podsylyuvalny element with two points, and in tripointLC-Autogenerators? trioma in specks.

Structural diagram of the harmonic oscillator

Let's take a look at the structural diagram of the harmonic oscillator. Oskіlki tse oscillator, then the mother of the inner life is to blame (ІП) Such a lansyug is a kolyvalny contour, which also vikonuvatime functions of a selective lancet (ІЦ). Viborchiy lansyug determines the frequency of colivans that are generated, that form. From the point of view of the vinification of the kolivan of the kolivny contour is sufficient, but the kolivny contour is a passive lance, and also a positive active opir Rіts. For the obviousness of this support, as well as the support of the tension Rn, in the yak the colivans are supplied, which are formed by the generator, the colivans will be extinguished. Therefore, it is necessary to include an element in the lance of the autogenerator that has a negative active support, as it seems, an element that is a negative active support, the core of a snake strum, and also an active (subsiluvial) element (UE). Opir of the auxiliary element Rue can fully compensate for all the wasted energy in the passive lances of the generator and the input. Also, before the autogenerator warehouse, it is necessary to turn on the lance, for the help of some part of the generator output, it is necessary to enter the auxiliary element to compensate for the costs, which is necessary for the lance of the return link (OS). Tsei lancer is also passive and may be positive active opir Roc. Also, the structural diagram of the harmonic self-oscillator (Figure 3) should be taken into account.

Figure 3 - Structural diagram of a harmonic oscillator

In the stationary mode of operation of the autogenerator, the positively active support of the passive elements of the generator and the pressure can be compensated by the negative support of the auxiliary element, tobto.

Ric+Roc+Rn— Rye = 0 (1)

The process of destroying the colivan in the autogenerator

Let's take a look at the process of destroying the colivan in the autogenerator (Fig. 3). When the dzherel zhellennya lances of the self-oscillator are turned on, fluctuations of the struma (fluctuation noise) are observed. The spectrum of this noise can be offset by warehouses at all frequencies. From this spectrum, behind the help of the selective stake, there are warehouses at the frequency of generation fg. Otrimane kolivanie at the exit of ІС to come along the lancet zvorotny zvorotny zv'azok in pіdsiluvalny element, dezdіysnyuєtsya stronger kolіvannya, yak go again to ІЦ and so on. . Under the hour of operation of the autogenerator, two modes of operation are seen: transitional and stationary. Transition mode The operation of the generator is three times from the moment the generator is switched on until the moment of stabilization of the parameters of the coliving. Stationary mode work is done to stabilize the parameters of coliving and to switch off the generator (Figure 4).

Figure 4 - Modes of robotic oscillator

Wash the self-excitation of the oscillator

In order to determine the self-excitation of the self-oscillator, it is necessary to take a look at it.

The transfer coefficient of the oscillator is determined by the virus

Kp=Kus? Kos (2)

de Kp - the complex value of the transmission coefficient of the oscillator;

Kus - the complex value of the coefficient of the strength of the subsidy;

Kos- The complex value of the coefficient of the serum.

As soon as you open the lance of the healthy link, then viraz for the coefficient of strength for matime looking

Kus= umwih/ umin=Kuse jjvus (3)

de Um in - complex amplitude of the input voltage of the driver;

Um vyh - complex amplitude of the output voltage of the driver;

Kus - strength coefficient module:

j us - argument of the module of the coefficient of strength.

Strength coefficient module

Kus =umwih/ umin (4)

j us vrakhovuє zsuv phases between the input and output voltages of the subsiluvach. Like a screaming baby 3, a pidsiluvach includes a pidsiluvalny element and a viborchy lansyug. It is assumed that, as a selection system, a parallel injection circuit with a support Rres. Todi

umwih= Im 1 ? Rcut (5)

de Im 1? amplitude of the first harmonic of the outward struma of the subsiluvial element

Mіzh Im 1 and Um vh іsnuє vzaєmozv'yazok, which is signified by virus

Im 1 = SWed? umin (6)

de Spr - the average steepness of the current-voltage characteristics of the subsiluvial element

Substituting the value of Im 1 from (6) to (5) is acceptable

umwih= SWed? umin? Rcut (7)

Then the module of the coefficient of strength of the subsidy, vrakhovuchi (4) and (7) will be more

Kus =umwih/ umin= SWed? umin? Rcut/umin= SWed? Rcut(8)

Vrahovoyuchi, sho j us will be one

jvus=jye+ jits (9)

de j ue - phase zsuv, which should be introduced by a subsilient element;

j іц - phase zsuv, which should be introduced with a selective lance.

Vrahovyuchi virazi (3), (8) and (9)

Kus= SWed? Rcute j (jye+jic) (10)

Transmission coefficient

Braid \u003d Um in x / Um wir \u003d Braid e j joc (11)

de Kos - the module of the coefficient of transmission of the lancet of the whistle-blower link;

j os - argument of the module of the coefficient of transmission of the lancet of the return link.

j os vrakhovuє zsuv phases between the inlet and outlet voltages of the lancet of the whirlpool.

In this way, depending on the variables (2), (10) and (11), it is possible to record the transmission coefficient of the oscillator in the stationary mode (with constant parameters) when generating sinusoidal waves

Kp=Kus? Kos= SWed? Rcut? Kose j (jye+jic+jos)=1 (12)

Viraz (12) equal to the oscillator. Zgіdno z cim rivnyannyam the transfer coefficient of the autogenerator in the stationary mode is to blame for adding one.

Self-excitation of the self-oscillator depends on the self-excitation of the self-excited generator.

1. Umov's balance of amplitudes

Kp= SWed? Rcut? Kos = 1 (13)

The transmission coefficient in the closed loop of the generator is responsible for adding one. That is, all the energy that is spent on the passive elements of the generator, that energy is to be compensated for by the energy of the replenishment of the auxiliary element.

Umov to the balance of amplitudes assigns a stationary amplitude of coliving.

2. Umov phase balance

jvus=jye+ jits+ jos=0 or k2 p, dek=1, 2, 3, … (14)

The total phase noise at the closed circuit of the oscillator is guilty of adding to zero or a multiple of 2p (360 ° ). That is, the energy of the replenishment of the subsiluvial element is due to be supplied at the phase with already clear colivans. For the vikonannya tsієї wash the lansyug of the virtuous link of the oscillator maє buti positive. The shards in most oscillator oscillators of the mind balance the phases only at one frequency, then the oscillator determines the frequency of generation.

Self-excited oscillator modes

Depending on the value of the constant voltage of life, it is brought to the electrodes of the subsiluvial element, and on the basis of the Cos coefficient, two modes of self-excitation are possible: soft and hard.

At to my own mode of self-excitation the position of the operating point (A) is determined by the linear separation of the current-voltage characteristics of the subsiluvial element (Figure 5). In this case, the cob regime of the subsiluvial element without the excitation of the external struma is ensured. In this mode, self-excitation is blamed for insignificant changes in the input voltage, as it is constantly guarded through fluctuations in the charges. In this way, the kolivany at the output of the subsiluvial element is blamed once, for insignificant changes in the input voltage, which is good for this mode of self-excitation. The amplitude of the surge at the output of the generator grows smoothly. In a stationary regime, the subsilience element can be used without a ventilator or with an outflow strum, moreover, in another slope, the outflow strum’s exit Q (half the trivality of the outflow strum’s pulse) is greater than 90 °. Vіdsutnіst vіdsіkannya аbо а great kut vіdsіchennya prizvodit to reduce the coefіtієnії dії (KKD) generator, є є nedolіkom tsgogo mode.

Figure 5 - Diagrams that explain the soft mode of self-excitation

At hard mode the position of the working point is determined beyond the limits of the current-voltage characteristics of the subsiluvial element (Figure 6). It is necessary to bring up the fact that the subsilience element is constantly working in the mode of outputting the output struma, after that, the impact on the output of the element is less when the input amplitude of the voltage u(t) of the singing value U n is overwhelmed. When the value is shifted (u(t)? U n), the subsyllabic element is visible, and the second output is called coli. Moreover, the amplitude of their colivan increases rapidly. The need for the presence of a singing voltage at the input of the subsilient element for the appearance of coli on its output in a short period of self-excitation.

In this mode, the self-excitation of the wind pipe is less than 90 °. The presence of a small kuta is used to increase the CCD of the generator, which is suitable for the regime.

Figure 6 - Diagrams that explain the hard mode of self-excitation

As you can see, the soft mode of self-excitation can have such advantages, which the hard mode cannot, and the hard mode can have these advantages, which the soft mode cannot. Therefore, in practice, in some types of generators (zocrema in LC-generators), there are different modes: when the generator is turned on and during the transitional mode, the generator operates in the soft self-excitation mode, and when the generator switches to the stationary mode, the generator switches over to the hard self-excitation mode.

Characteristics of the oscillator

Kolivalna characteristic is the amplitude of the amplitude of the first harmonic of the output struma of the subsiluvial element Im 1 in the amplitude of the input voltage Um in at a constant displacement voltage U 0 and the open lance of the swivel link.

Qi characteristics may have a non-linear character, to which the element is non-linear and lie in the mode of self-excitation of the generator. On little 7, a, the characteristic of the generator in the soft mode of self-excitation is presented, and on little 7 b? in a zhorsky mode of self-excitation.

Figure 7 - Coil characteristics of the oscillator

linesє zalezhnist vyhіdnoї nasprugi lancet zvorotny svyazku Um vyh vіd amplitude of the first harmonic of the input stream Im 1 .

Оскільки вихідна напруга ланцюга зворотного зв'язку є вхідною напругою підсилювального елемента, а вхідний струм ланцюга зворотного зв'язку є вихідним струмом підсилювача, лінії зворотного зв'язку зручніше представити щодо підсилювача як залежність вхідної напруги підсилювального елемента від амплітуди першої гармоніки вихідного струму (рисунок eight).

Figure 8 - Lines of the inverted ligament

The lines of the pivotal link show the linear fallowness, to that the lancet of the pivotal link is a linear lancet. Nakhil liniy to deposit in the form of a coefficient of svorotnogo zv'yazku Kos. What is more Kos, tobto chim the strongest zvorotnyy zv'azok, Tim is the smallest Kut nakhil shodo osі Um vh, for example, on the little one 8: Kos 1<Кос 2 <Кос 3 .

Designation of stationary amplitude of coliving

From paragraph 1.6, it is clear that in the autogenerator, one hour at a time, one can find a linear (line of the turning link) and a non-linear (collisional characteristic) of fallow land. In the stationary mode of the self-oscillator, the voltage amplitude Um in and out is similar to the amplitude of the stream Im 1 of the substantia element is responsible for satisfying two fallows at once. It is possible to have less at the points of the peretina of the colival characteristics with the line of the swivel link. Let's take a look at the process of designating the stationary amplitude of colivans in different modes of self-excitation.

M'yakiy mode samoozbuzhennya.

To analyze the processes that are used in autogenerators, it will be necessary to change their characteristics in one coordinate axis and in one scale (Figure 9).

On the little one there are two lines of the whirlpool with different coefficients of the whelk of Kos 1 and Kos 2 and Kos 1<Кос 2 . При Кос 1 колебания отсутствуют, т. к. колебательная характеристика и линия обратной связи имеют одну общую точку 0, а значит Um вх =0 и Im 1 =0. При Кос 2 колебательная характеристика и линия обратной связи имеет две общие точки 0 и В. Поскольку, как отмечалось выше, в точке 0 колебания не возможны, то устойчивые колебания возможны только в точке В при напряжении равном Um вхВ и соответствующем ему током Im 1В. Точка В является became a point of jealousy that is consistent with the stationary mode of the robotic generator. At the point of steel, the balance of the energy of the addition of the subsiluvial element and the energy of the inputs is monitored. Until this point, the generator comes to the process of self-excitation. As a result, I’m pouring into the generator of various destabilizing factors of wines, I can become stable, but the amplitude of the surge will turn to the point of stable jealousy. Let's take a look at the processes, like in autogenerators in different countries.

Let's assume that the voltage at the input of the subsiluvial element has changed the value of Um vhs. Qia voltage is called at the output of the jet generator Im 1 C . This strum zvdyakova zvorotnoy zv'yazyka increase the voltage at the input of the element to Um in D , and tse, with his blackness, bring the strum to an increase to Im 1 D . This stream will be brought to an increase in the voltage, etc. If it will be increased until the amplitude of the surge reaches the value of point B. If the amplitude of the surge, under the influence of destabilization factors, increases to the value of Um vxE, then there will be a reversal process, i.e. i.e. calling out the spring of the elastic strum Im 1 E zavdyaka to the inverted link, bringing the voltage Um in to a change, etc., the docking amplitude will not turn again to the value of point B.

Hard mode of self-excitation.

In this mode, the kolivalny characteristic of that line of the turning link can be three hot points 0, A and that (Figure 10).

Figure 10 Determining the stationary amplitude of colivans in hard mode

At point 0, they can’t coli. Let's analyze point A. Change the amplitude of the surge at the input of the subsilient element up to Um inc, change the strum at the outlet lance Im 1C, which at its edge has brought the voltage Um in to a change, the voltage has brought the strum to a change Im 1 and so on. , Doki kolyvannya not go out. If the voltage at the input of the auxiliary element increases to the value Um in D, then the amplitude of the surge will increase to point B. In this way, point A є point of unsteady jealousy, at these points, you can have a knockout, but if you change their amplitude, the stench will either fade away, or their amplitude will increase. If you want to analyze a point, then it will show up as a point of steady jealousy.

The oscillator can be operated in soft or hard modes of self-excitation. For the Rozkritty of the Specials, the Tsich regimen of the imperative of the self -linen is spirally like amplibudna characteristic of the Pidsilyuvach with the OOS (Vlasna Pіdsilyvach), the upper Zapzhdi is MAHENINIINIST, I am the characteristic of the butt -ica, the lineniye (lantsi zero (lantsi

On fig. 3.2, a a typical amplitude characteristic of a non-linear substation is presented.

При малих вхідних сигналах вихідний сигнал змінюється пропорційно до вхідного (підсилювач має постійний коефіцієнт посилення, рівний тангенсу кута нахилу АХ до осі абсцис), при великих вхідних сигналах зазначена пропорційність порушується (коефіцієнт посилення підсилювача залежить від амплітуди вхідного сигналу). The line of the turning link is a straight line drawn under the hood to the abscissa axis, so that between the vihdnoy and the tensile OS, a linear fallow is observed.

At the moment of turning on the life of the autogenerator at the input, there is noise, which can have a wide range of frequency storage, storage space, the frequency of which is the resonant frequency of the selection system. It should be noted that other spectral warehouse noise will be choked by the other world's choice system. On the way out Before once an exit signal appears, which after weakening by the lancet of the PIS, once it is at the entrance of the subsidy, you can see the voltage. The process will be carried out until the time when the amplitude of the external coagulation reaches a stationary value (it will be determined by the mind's balance of amplitudes).

3 fig. 3.2, a it is seen:

mottled BUTє the point became ї rivnovagi;

generation is only possible for such minds, if the line of the turning link changes the amplitude characteristic of the subsidy, which shows the vikonannyu of the mind.

A closer look at the self-excitation mode of the oscillator is called m'yakim. For yoga safety, it is necessary that the AH of the subsidiary was from zero and small on the cob of coordinates of the linear plot with a sufficient kutom nahely to the abscissa axis.

The soft mode of self-excitation of the generator is characterized by the following features:

§ AH pіdsilyuvacha і direct zvorotny zv'yazok peretinayutsya only in one point, like a point of dynamic equalization;

§ colivannya, to change the PIS coefficient β , blame (pripinyayutsya) at the same PIC coefficient;

§ when zbudzhennі oscillator is not required zovnіshnіh vplivіv;

§ in case of soft mode of self-excitation of the generator, it is possible to set the set amplitude of the co-living by means of the selection of the POS coefficient.

Together, about those traces, it is important that the soft mode of the autogenerator is economically negligible, the oscillators of the autogenerator work in the linear mode and її k.p.d. do not exceed 50%.

Irrespective of the designations, the soft mode of self-excitation is the main mode of self-oscillators.

The process of destruction of the colivan is required otherwise, as if it were possible S- Obraznu AH (Fig. 3.2, b). With the installed PIS coefficient β < β 2 AH pіdsilyuvacha that POS line does not have a cross point. Tse means that the PIC coefficient is small, and the oscillator does not start.

With the installed PIS coefficient β 1 < β < β 2 AH pіdsilyuvacha that line POS maє two points of the line BUTі W. Tse means that the mind balance of the amplitudes is adjusted for two values ​​of the amplitude of the oscillator.

Krapka W characterizes the non-stable camp of the self-generator. Let the amplitude at the output of the generator give a point W, with which the coefficient of strength in the air is improved Before S. Supposedly, under the influx of a noble official, the amplitude of the ringing changed. Tse bred to change the signal at the input of the generator, shards U VX = β U VIR, and more farther away the change in the amplitude of the vihіdnyh koliva, Before less lower Before W . The result of a swelling infusion will be a sight of colivan in this fluctuation. Navpaki, as if due to the outside factor, the amplitude of the colivan increases, then the signal at the input increases. Tse vykliche away zbіlshennya amplitude vihіdnіh kolivany, yak vіdbuvatіme dоti, docks the system does not go to the stationary camp .

Krapka BUT characterizes a stable (stationary) camp of an autogenerator, with which the coefficient of strength in the air is improved to A. It is acceptable that, according to the difference of the ovnishny factor, the amplitude of the colivan, which indicates the points BUT, changed. Tse bred to change the signal at the input of the generator, shards U VX = β U WIR. However, the oscali Before who has more vіpadku Before And the input signal will be more powerful and the amplitude of the output signal will increase and will again show points BUT.

Obviously, in order to start the oscillator, the amplitude of the wakeful infusion can change the value of the amplitude of the input signal, which W. The oscillator wake-up mode is called harsh.

In times, to install the PIS coefficient β = β 2 , then the oscillator works just like that, like in a soft mode, with which there is a point of stability.

Let's look at how the amplitude of the colivane changes, how the coefficient of the POS changes, and the outside day.

Apparently, before looking at it, the generator will not start up, like β < β 2 (line PIS β pass levoruch behind the line β 2). The start of the generator will not be possible and at a glance, as β 1 < β < β 2 (line PIS β pass between lines β1і β2) The generator wakes up less at vipadku β = β1, at which the stationary amplitude of the colivation is established. As soon as the generator was started, they changed the coefficient β between β 1 < β < β 2 , then I won’t see the colivan, the amplitude of the colivan will change less . The sight of the kolivan will be at the fall, if β = β 2. To update the calculation, it is necessary to re-install the PIS coefficient β = β 1 .

In this rank, the hard mode of self-excitation of the generator is characterized by the following features:

§ the curve of the coefficient of strength of the subsilyuvacha may have a point of inflection and overlap with the straight line PIC at one or two points;

§ іsnuє two values ​​of the critical coefficient ПІС ( β 1 ta β2), what do you need to start and see how the oscillator is energized;

§ Amplitude of pulsing for a critical PIC start-up β 1 cannot be close to zero;

§ іsnuє mozhlivіst to start the generator when β 1 < β < β 2 for the rahunok of the cob ovishny mail.

The oscillator's hard mode is economical (the oscillator has the highest efficiency), the lower mode is soft, the oscillators are practicable in the non-linear mode. In the hard mode, it is impossible to take off a small amplitude, and the start of the generator is much more complicated. The hard mode of self-excitation of autogenerators rarely stops.