LF HF filters at the front cascades of LF. Low frequency cascades. Sorry, two-cascade pidsiluvachs

Let's introduce the term "acoustic indicator":

(20)

The value of M can be understood from fig. 12 shows a typical transmission characteristic of a field-effect transistor with a p-channel.

Nakhil curve at U z.i = 0 dorіvnyuє S max. Yakshcho dotichnu at the point U z.i =0 continue to the crossbar from the axis of the abscissa, it is not visible at the axis of the vdrіzok U ots /M. Tse is easy to show, vihodyachi s (20):

(21)

Otzhe, M є the world of non-linear characteristics of the field-effect transistor. It is shown that field-effect transistors were prepared by the diffusion method M = 2.

We know the value of the struma I c0 behind the virase (21):

Substituting this value (19), we take:

If formula (1) put R i >> R n, then the coefficient of strength for the voltage for the circuit with a hot dzherel

(23)

Substituting the value of the strength coefficient (23) for viraz (22), we take:

(24)

Zі spіvvіdnoshennia (24) it is possible to increase the offensive visnovok: when the voltage of life is given, the coefficient of the strength of the cascade is wrapped in the proportional voltage of the output of the field-effect transistor. So, for field-operated transistors, prepared by the diffusion method, M = 2 і at U ots1 = 1.5 (KP103E), U ots2 = 7 V (KP103M), the voltage of life is 12.6 V and U c = 7 V apparently 7.5 and 1.6. Cohefitsіnti the Grozlennny Kaskada Z PT1 brushes more, Yakshcho for Rahunok Zbilnehnnya Navantazhni Rnovykit U U to 1.6 V. Slid, in the Tsom Vipad with an unstable napruster, , Chim a transistor with a greater coolness (for a greater support of the voltage).

At times of small support Rn, it is necessary to use polytransistors with a large voltage output for a larger gain coefficient (for a gain factor S).

In transistors with a low voltage, the change in the drain stream at a temperature is less, lower in transistors with a high voltage, and therefore, until the stabilization of the working point is lower. When zsuvah on the gate, to set a zero temperature coefficient to change the drain stream, for transistors with a lower voltage stream, the drain is higher, lower for a transistor with a higher voltage stream. In addition, the voltage fluctuations on the gate (at zero temperature coefficient) of the other transistor are larger, then the transistor is more efficient in the mode, with which the non-linearity of its characteristics is more pronounced.

With a given voltage of life, the polytransistors with a low voltage output allow you to take a larger dynamic range. For example, with two transistors, which can generate a voltage output of 0.8 and 5 with a voltage of 15 and a maximum voltage support, which is supported by a spіvvіdnoshennia (18), at the output of the first one, you can take a variable amplitude of the output signal (depending on the Um vіds), equal to 14.2 V, in that hour, like in another, it is less than 10 V. Vidminnіst in the future will be better, if E p is changed. So, if the voltage of life is reduced to 5 V, then the amplitude of the output voltage of the first transistor is doubled to 4.2 V, it is practically impossible to use another transistor for these purposes.

Non-linear creations in pidsiluvachs

The magnitude of the non-linear effects that the voltage switches have on the FET is determined by the parameters of the circuit: displacement, operating voltage, voltage support, equal to the input signal, and characteristics of the field-operated transistors.

When applying a sinusoidal voltage U 1 sinωt to the input, the value of the total voltage in the lance gate - dzherelo can be recorded

U z.i \u003d E cm + U 1 sinωt

de E cm - the voltage of the ovnіshny usunennya, filed on the shutter.

Vrakhovuyuchi quadratic deposit of the stream to the drain and the voltage on the gate (1),

(24a)

Crooked arches in rіvnіnі (24а), otrimaєmo razgornuty viraz for strum runoff:

From the view (24b) it can be seen that the output signal has an order with the constant warehouse and the first harmonic, another harmonic of the input signal frequency.

The non-linear effects are set from the RMS value of all harmonics to the RMS value of the fundamental harmonic of the output signal. Vykoristovuyuchi tse appointment, s virazu (24b) we know the coefficient of harmonics, virazivshi (E cm -U ots) through I s0:

(24v)

Viraz (24c) gives only an approximate result, but the real passing characteristics of the PT are similar to those described by (1).

To reach the minimum non-linear solutions, it is necessary:

Increase the value of U s.i.

U s.i ≥(1.5...3)U ots

Do not work at the voltages of the shutter - st_k, close to the breakdown;
- Opіr navantazhennya vibiraty dosit great.

On fig. 16, a circuit is induced, in which the polovy transistor works with a larger R n, which ensures little creation and high strength. As an opir of interest, here another half-pole transistor T2 is victorious. This circuit provides a power factor of approximately 40 dB at E pit = 9 V.

Choose the type of PT, which ensures the least amount of leakage, to fall in line with the input signal, the voltage of life and the necessary smog of transmission. With a great equal output signal and a significant smoothness of the transmission of the bazhan PT with a great U wind. With a small equal input signal, or a low pressure of life, the FET is overestimated with a small U winds.

STABILIZATION OF THE COEFFICIENT OF THE SETTLEMENT

The coefficient of strength of the ULF on the PT, as well as on other active elements, is weaker to the influx of various destabilizing factors, under the influence of such faults it changes its value. One of these factors is change the right temperature. To fight with these phenomena, the same methods are mainly used, which are used in circuits based on bipolar transistors: to reverse the reverse link, both along the stream, and on the pressure, which is one or more cascades, introduce temperature-deposited elements into the circuit.

In a field-effect transistor with a p-n junction, the temperature changes according to the exponential law of the strum of a reversed shutter, the flow streak and coolness change.

Having added a change in the gate struma I s the strength coefficient can be weakened by changing the resistor opir R s of the gate lung. To change the flow, change the stream to the drain, as in times of blocking of bipolar transistors, a negative return link of the constant stream can be reversed (Fig. 13, a).

Let's take a look at the report on ways to change the injection of the coefficient of strength to change the coolness of S.

In the weak signal strength mode, the strength coefficient of the uncompensated cascade on the field-effect transistor decreases with increasing temperature. For example, the coefficient of strength of the circuit in Fig. 13 a, equal 13.5 at 20 ° C, changes to 12 at +60 ° C. Parameters zsuvu, so like a stream drain I s, voltage between the gate and coil U z.i voltage between coil and drain U c.

Rice. 13. Schemes for strengthening the strengthening coefficient.

a - non-compensation cascade; b - compensation cascade of reinforcement; - Compensation cascade of settlements with environmental protection; g - transitional characteristic.

Turning on a sprat of significant diodes at the lances of a negative winding link between the shutter and the coil (Fig. 13 b), it is possible to stabilize the strength coefficient of the signal without introducing additional cascades. With an increase in temperature, the direct voltage of the skin diode decreases, which leads to a change in the voltage U z.i.

It has been experimentally shown that the resulting change in the pressure moves the working point in such a way that the twist S is visually stable at the most significant temperature changes (Fig. 13, d). For example, the coefficient of strength of the pidsiluvach for the scheme of fig. 13 b, equal to 11, practically retains its value in the range of temperature changes of 20-60 ° C (K and changes by 1% in total).

The introduction of a negative reversal link between the gate and the coil (Fig. 13, c) changes the strength coefficient, but also improves stability. Coefficient of strength of the subsidyuvach behind the scheme of fig. 13, equal 9, practically does not change when the temperature changes from 20 to 60 °.

By means of a relay selection of the working point and the number of diodes, it is possible to stabilize the coefficient of strength with an accuracy of 1% in the range up to 100 ° C.

CHANGING THE INPUT OF THE INPUT CAPACITY OF THE FET AT THE POWER FREQUENCY OF THE PIDSILYUVACHIV

For the cob repeater shown in Fig. 11 a, according to the yogo equivalent scheme (Fig. 11, b) the constant hour of the entrance lance can be determined with sufficient accuracy for practical rozrakhunkіv coming rank:

τ in \u003d R g [Z g + Z z.s + Z z.i (1 - Before i)], (25)

de R r and C r - parameters of the signal.

From virazu (25) it can be seen that the post-hour of the entrance lance is in direct fallow in the form of capacities C s.s і Z s.i, moreover, the capacity of Cs.i for the rahunok inflow of the environmental protection is changed (1-K i) times.

However, the reduction of the coefficient of strength in terms of voltage, close to one (with the method of using the injection of the capacity Z z.i), in the scheme of the great repetition of the turn, it is associated with difficulties, due to the low breakdown voltage of the field-effect transistor. So, on a field-effect transistor KP102E with a maximum stream drain I c0 \u003d 0.5 mA, a maximum steepness of 0.7 mA / V, and a coefficient of strength for the voltage of 0.98, it is necessary to vicorate the opir R n \u003d 65 kOhm. At I c0 \u003d 0.5 mA, the voltage drop on the opir R in the warehouse is close to 32.5 V, and the life voltage can be, at least, more than the voltage by the value of U ots, then E p \u003d 35 V.

In order to eliminate the need for a high voltage voltage to eliminate the power factor close to one, it is practical to install circuits for combining repeaters on pole and bipolar transistors.

On fig. 14, and the circuit is shown as a combination for the type of transistors, which are placed in it, and for the circuit of their circuit, which is called a turn repeater with a link. The stack of the field-effect transistor T1 is connected to the base of the bipolar transistor T2, from the collector of which the signal is sent to the output of the field-effect transistor in antiphase with the input signal. With the selection of resistors R5 and R6, it is possible to take the voltage of the signal to the cob equal to the input voltage, by the same token, by adding the capacitance Z z.i.

Resistor R1 is installed in the lantern of the shutter, attached to the cob of the transistor T1 through a high-capacity capacitor C2. The effective opir at the lanziug displacement is determined by the support of the resistor R 1 and the coefficient of the turning link, so that

(35)

de U - the amplitude of the signal to the cob of the transistor T1.

Rice. 14. Schemes of subsidiaries with a changed input capacity.

a - і stock repeater іz stitch with a tongue; b - from the changed єmnistyu Z z.s; c - Historical repetition with dynamic ambitions.

With large values ​​​​of the bipolar transistor T2, the coefficient of strength of the circuit can be approximately estimated by the onset of viraz:

(36)

As for the sub-functions for work at low frequencies, then the resistor R6 can be shunted with a capacitor C3 (Fig. 14, and the indications are dashed); under which the upper frequency boundary is determined by the frequency

(37)

More recently, the method of changing the gate capacitance inflow - winding Z z.i on the frequency response of the power switch with a path of control at the turn repeater of the gain coefficient, close to one, was considered. Inflow of capacity Z z. under which it became immutable.

Further, the increase in the frequency characteristics of the power supply can be reached with additional weakening of the static capacitance of the shutter - stick at the input port of the circuit.

To change the capacitance injection between the gate and the drain, you can use a method similar to the one described above, to reduce the capacitance injection of Z z.i, to change the signal voltage on the capacitance. The scheme shown in Fig. 14 b, having added the capacity of the 3 s.c.

The first cascade on the transistor T1 may be less energized in the lancet drain and for the signal that is taken from the turn, it is repeated. The output signal is fed to the cascade by a hot collector, which has a bipolar transistor.

To reduce the inflow of capacitance Z z.s, the signal from the output stage (emitter repeater) is fed through capacitor C2 to the transistor T1 at the phase with the input signal. To improve the compensation effect, it is necessary to use inputs to increase the transmission coefficient of the first stage. It can be reached by supplying a resistor R3 to the signal of an earth repeater. The result has a voltage that is applied to the stick, it becomes more, and a negative return signal - less. In addition, the increase in the transmission coefficient of the first cascade additionally changes the influx of capacity Z z.i.

If you want to overcome the method of lowering the gate capacitance, then the input capacitance, sound, is significant (for the KP103 transistor, set 20-25 pF). As a result, we change the input capacitance to 0.4-1 pF.

Historical repetition with dynamic ideas (According to the materials of Yu. I. Glushkov and V. N. Semenov), stitching stitches with a back stitch on the stitch, images in fig. 14, Art. For the help of such a scheme, it is possible to turn on the injection of a static gain coefficient of the field-effect transistor on the transfer coefficient of the turn repeater, as well as change the capacitance of Z z.s. Transistor T2 plays the role of a stable strum generator, setting the strum at the cob of the field-effect transistor T1. Transistor T3 є dynamіchnym navantazhennyam in lansyuzі to the drain of the field-effect transistor zminny strum. Parameters of the string repeater:

ECONOMY ULF

In front of the retailer, if there is a task of creating low-frequency low-frequency power supplies, as if they are working in the form of a low-voltage power supply. In such subsidiaries, there can be only a few field-operated transistors with a small voltage output U ots and a stream of intensity I s0; qi circuits can be unparalleled in front of lamps and circuits on bipolar transistors.

The choice of working point in economical substation on field-operated transistors is determined depending on the mind and the minimum tension that arises. For which voltage of the displacement U z.i, it may be chosen equal to the voltage of the discharge, with which stream the drain is equal to zero. This mode ensures the minimum heating of the transistor, which makes the gate turn up to small strums and the high input support. The necessary coefficient of strength with small streams to the drain reaches the greater support of the charge.

In economical low-frequency power supplies, the cascade circuit shown in Fig. 1 is widely used. 10b. In this scheme, the voltage is shifted on the support of the lancet coil, which creates a negative reversal link along the stream, which stabilizes the mode in the flow of the temperature fluctuation and the change of parameters.

It is possible to propagate such an order for the development of economic cascades of the ULF, which are shown in fig. 10b.

1. Vyhodyachi z mind otrimannya minimum rozs_yuvanoї natuzhnosti, vibiraemo polovy transistor z small vіdsіchennya U ots і strum nasichennya I s0 .
2. I select the operating point of the field-effect transistor with a strum I c (one - tens of microamperes).
3. Vrakhovyuchi, that when the pressure is close to the pressure of the vіdsіkannya, the strum runoff can be approximately assigned to the viraz

Rc ≈ U ots /R ta (38)

opir at the cob

Rі ≈ U ots /I і (39)

4. Depending on the necessary coefficient of strength, we know R n. Oskіlki coefficient of strength

(40)

those that are not shunting the differential support drain-coil R i and presenting the replacement of S її value, omitting the path of differentiation to the stream for the stream to the drain (40), it is necessary:

(41)

From the rest, we know the necessary opir of the venture:

(42)

At the same time, the rozrahunok pіdsilyuvacha ends and in the process of regulation, the ratings of the resistors R n and R і are no longer specified.

On fig. 15, a practical scheme of an economical low-frequency power supply is introduced, which works in the form of an ionic sensor (for example, in the form of a p'ezoceramic hydrophone).

Zavdyaki small struma usunennya vyhidnogo pіdsilyuvacha, scho z dvoh transistorіv T2 and T3, the intensity of the rosette of the entire front pіdsilyuvacha become 13 microwatts. The front pressure switch slows down the strum of 10 μA at a pressure of 1.35.

Rice. 15. Principal scheme of the economic subsidy.

The input opir of the front switch is determined by the support of the resistor R1. With the help of the input support of the field-effect transistor, it is possible to nextuvat, but it is better to increase the support of the resistor R1.

In the modes of small signals, the input cascade of the front pilot switch is equivalent to the circuit with a high turn, in that hour, as a lancet, the switch is reversed, like in the repeater circuit.

Vicorization in this circuit is due to the mother’s low voltage Uots and a small stream to drain I c0 at gate voltage U z.i = 0.

The conductivity of the channel of the field-effect transistor T1 lies in the stream to the drain, and the remaining fragments are insignificant, then the conductivity is small. Therefore, the output circuit of the circuit from the hot dzherel is determined by the support of the resistor R2. Behind the data, the output opir of the power supply is 4 kOhm, the voltage strength coefficient is 5 (14 dB).

CASCADE ULF WITH DYNAMIC NAVIGATION

Polyolefin transistors make it easy to implement low-frequency power supply circuits with dynamic voltages. Porivnyann with a rheostatic cascade of strength, for which opir is constantly driven, a booster with dynamic stress can have a greater coefficient of strength for a strain.

The principle scheme of the substation with dynamic advances is shown in fig. 16 a.

As a dynamic support for the drain of the field-effect transistor T1, the active element is the field-effect transistor T2, the internal support of which lies in the amplitude of the signal at the drain of the transistor T1. Transistor T1 is switched on behind the circuit from the hot dzherel, and T2 - behind the circuit from the hot drain. According to the constant stream, the transistors are sequentially switched on.

Rice. 16. Principal schemes for stimulating dynamical innovations.

a - on two PTs; b - on PT and bipolar transistor; c - with the minimum number of details.

The input signal U input is fed to the gate of the field-effect transistor T1, and is taken from the cob of the transistor T2.

The cascade of strength (Fig. 16, a) can be typical when there are rich cascades of subsidiaries. When using field-operated transistors of the KP103Zh type, the cascade can have the following parameters:

It should be noted that with a different field-operated transistor with a small voltage output, it is possible to take a larger coefficient of strength in terms of voltage, lower with a different field-operated transistor with a larger voltage output. We appreciate that the internal (dynamic) opir is larger for the PT with a small voltage of the inner (dynamic) opir, the lower one is for the PT with a high voltage of the wire.

As a dynamic opir, it is possible to beat the great bipolar transistor. At the same voltage strength coefficient, it will turn out to be three times higher, lower at a higher dynamic voltage of the field-effect transistor (for a larger R i). And in this way, there are a lot of details that are necessary for strengthening the cascade with dynamic ambitions. The schematic diagram of such a cascade is shown in Fig. 16 b, moreover, the parameters of the yogo are close to those of the anterior support, shown in fig. 16 a.

Pіdsilyuvachі z dynаmіchnym navantazhennyam sled vikoristovuvat for otrimannya great coefficient of strength of low-noise VLF with low pressure zhivlennia.

On fig. 16, the image is a powerful cascade with dynamic inputs, in which the number of parts is reduced to a minimum, and the circuit provides a gain factor of up to 40 dB at low noise level. The strength of the voltage for the scheme can be expressed by the formula

(43)

de S max1 - the coolness of the transistor T1; R i1 R i2 - dynamic supports of transistors T1 and T2

ULF ON MICROSCHEMS

The microcircuit type K2UE841 is one of the first linear microcircuits mastered by our industry. Vaughn is a two-stage substation with a deep negative turning signal (repeat), picking up on field transistors. Microcircuits of this type have been widely used as input cascades of sensitive wide-range switches, as wine cascades when transmitting signals through a cable, active filter circuits and other circuits that affect high input and low output support and stable coke.

The basic electrical circuit of such a power supply is shown in fig. 17 a; ways to turn on the microcircuit - in fig. 17, b, c, p.

Resistor R3 introduces into the circuit of the outgoing transistor in the case of short circuits in the output. Small changes in the return link (in Fig. 17, in R os shown by a dotted line) can be taken off the transmission coefficient, which is more expensive or less.

The input opir of repetition can be significantly increased (by 10-100 times), so that after the help of the capacitor 3, the return clatter at the shutter latch (shown by the dotted line in Fig. 17, c) is added. With this input, the repetition is approximately more expensive:

R in \u003d R s / (1-K i),

de K i - transmission coefficient of the repeater.

Main electrical parameters and foot repeater:

The industry has mastered the production of hybrid fused microcircuits of the K226 series, which are low-noise low-frequency power supplies with a polytransistor at the input. The main feature is the strengthening of weak signals in the changeable stream in the sensors with a high internal support.

Rice. 17. Microcircuit K24E841.

a - principle diagram; b - scheme with one dzherel of life with a voltage of 12.6; c - circuit from two dzherelami living with a voltage of + -6.3 V; d - scheme with one dzherel of life with a voltage of -6.3 Art.

Microcircuits of the viconan on the mains pad for the hybrid-fusion technology from the installation of the polypolar and bipolar frameless transistors.

Low-frequency power supply microcircuits are divided into groups according to the noise gain coefficient and noise level (Table 1). Starry look and dimensions are presented in fig. eighteen.

Principal electrical circuits of subsiluvacs are shown in fig. 19 a, b and 20 a, b, a 21 a, m. With the inclusion of microcircuits behind the circuits of Fig. 21, and i input opir pіdsilyuvachіv dorіvnyuє support ovnіshny resistor R i . To move the input support (up to 30 MΩ or more), it is necessary to twist the diagrams of Fig. 21.6, p.

Table 1

Rice. 18. Old look and dimensions of K2US261-K2US265 microcircuits.

The main electrical parameters of microcircuits K2US261 and K2US262:

Rice. 19. Principal schemes of subsidiaries.

a - K2US261; b - K2US262.

Rice. 20. Principal schemes of subsidiaries.

a - K2US263; b - K2US264 (usі diode type KD910B).

The main electrical parameters of microcircuits K2US263 and K2US264:

Rice. 21. Schemes for switching on subsidiaries.

Recommendations for the placement of microcircuits. Frequency delay and boundary frequency beyond 0.7 V in the region of lower frequencies when reaching the great constant hour of the input lance is determined by the outer capacitor of the filter of the negative winding link C2 and the support of the lancet resistor of the turning link R o.z is inactive before sleep:

Peak voltages at the inputs of K2US261, K2US262 microcircuits are not responsible for changing 1 for positive polarity and 3 for negative; at the input of microcircuits K2US263, K.2US264 - no more than 2 for positive polarity and no more than 1 - for negative.

Opir coil R1 for entrance struma in the range of operating temperatures -60 to +70 ° C, it is not guilty to exceed 3 MΩ. In the range of lower maximum temperatures, or when it is reduced to the value of the output voltage of the resistance of the resistor R1, it can be increased by the method of increasing the resistance of the input stage.

The stream of the coil of the input capacitor C1 is not guilty of overshooting 0.06 μA.

To save the maximum output voltage, the jet coil of the capacitor C2 in the operating temperature range is not guilty of exceeding 20 μA. This can be satisfied with a capacitor of the K52-1A type with a capacity of 470 μF, the stream does not exceed any coil at a voltage of 10 μA.

PRACTICAL LOW FREQUENCY PIDSILUVACH CIRCUITS ON FOLET TRANSISTORS

Zzvich polovі transistors vikoristovuyutsya in pіdsilyuvachah with bipolar transistors, but you can also zastosovuvatі as active attachments in rich cascade pіdsilyuvacha sound frequency with resistive-snіznіsny zv'yazyk. On fig. 22, the butt of the use of field-operated transistors in the RC circuit is shown. The scheme of the sound signal of the sea was victorious. The signal to the input of the power supply was taken from the p'ezoceramic hydrophone G, and the input of the power supply was a cable of the type KVD4x1.5 with a length of 500 m.

The input cascade of the dimmer switch on a field-effect transistor of the KP103Zh type with a minimum noise coefficient. For the purpose of measuring (changing noise), the two first stages are livened with a reduced voltage, which is taken for the help of the parametric stabilizer D1R8. Zavdyaki tsim calls equal noise, pointing to the entrance, at smooth frequencies of 4 Hz-20 kHz, becoming 1.5-2 μV.

To adjust the frequency response of the power supply in the region of high frequencies, in parallel with the resistors R6 and R10, you can connect additional capacitors to correct them.

To use a high-voltage power supply support with a low-resistance voltage (cable), serve as a voltage repeater on transistors T4, T5, which is a two-stage power supply with a non-intermediate sound. For the use of a shunting resistor shifting R11, R12, a positive return is introduced along the changeable stream through the lanyard R13, C6. Rozrahunkov's value of the output support of such a repeater is 10 ohms.

To re-verify the practicality and the coefficient of strength of the power supply, serve as a calibration generator, selections for the scheme symmetrical multivibrator. The calibration generator is of the form of a direct-current stabilized amplitude behind the additional stabilizer diodes D2-D5 type D808, pulses with a frequency of 85 Hz, which, at the moment the calibrator is turned on, are fed through the hydrophone to the input of the power supply. For the help of the dilnik, the voltage on the resistors R16, R17, the amplitude of the pulses was set equal to 1 mV.

Regardless of the simplicity of the scheme, the boost coefficient changes insignificantly (about 2%) when the current temperature changes in the range of 0-40 ° C, and the boost coefficient at a room temperature of 20 ° C reaches 150.

Rice. 22. Principal diagram of a hydroacoustic pidsiluvach.

Since the first stage of the first cascade on the field-effect transistor should be lowered, so that we can get stuck in the upcoming cascades of the most powerful bipolar transistors, then it is not economical to beat the field transistors for further strengthening. In these cases, subsiluvacs, like vikoristovuyut poles and bipolar transistors, are blocked.

On fig. 23 shows the principle diagram of a low-frequency power supply on a field and bipolar transistors, which can be close in terms to a three-stage R-power switch on field transistors (Fig. 22) parameters. So, with a gain coefficient that is equal to 150, the frequency response is equal to 0.7 at 20 Hz up to 100 kHz, the value of the maximum output of the uncreated signal at R n \u003d 3 kOhm is equal to 2 V.

The polyol transistor T1 (Fig. 23) is switched on behind the circuit with a hot dzherel, and the bipolar one is behind the circuit with a hot emitter. For the stabilization of the working characteristics of the subsidiaries of the entanglement with a negative backlash of the fast strum.

On fig. 24 shows a diagram of a low-frequency signal booster with mid-range links, developed by V. N. Semenov and V. G. Fedorin, recognized for strengthening weak signals from a dzherel with a high input support. Pіdsilyuvach do not take revenge on different condensers, so the dimensions can be small.

The parameters of the pidsiluvach are as follows:

The scheme is a UPT with a 100% turn-around call on a steady stream; rahunok tsgogo reach minimum drift and stability regimes. The return link of the steady strum is introduced through the low-frequency filter, so the lower cut-off frequency of the subsidy is determined by the parameters of this filter.

To stabilize the coefficient of strength, there is a negative turnaround at the frequency of the signal with a depth of close to 20 dB. Posilennya to lie down in the depths of the whirlpool.

Rice. 23. Principal diagram of ULF on field and bipolar transistors.

Rice. 24. Principal scheme of ULF with no-intermediate links.

Zastosuvannya zvorotnykh zv'yazkіv to rob pіdsilyuvach non-critical to change the voltage of life and rozkidannya parametr_v transistors and all parts, crim R10 and R11. Before the features of the circuit, you can see those that the transistors T3 and T4 work with the voltage U b.e., which are more expensive U k.e.

The high input opir of the subsidiaries reaches the zastosuvannya of the field transistors. At the lower frequencies, it will be the support of the resistor R1, the upper ones - the input resistor of the circuit.

A.G. Milekhin

Literature:

1. Polymer transistors. Physics, technology and zastosuvannya. Prov. from English for red. O. Mayorova. M., "Radyanske radio", 1971.
2. Sevin L. Polyov transistors. M., "Radyanske radio", 1968.
3. Malin V. V., Sonin M. S. Parameters and power of field-effect transistors. M., "Energy", 1967.
4. Shervin V. Causes of creation in subsidiaries on floor transistors. - "Electronics", 1966, No. 25.
5. Downes R. Economical front podsiluvach. "Electronics", 1972 No. 5.
6. Holzman N. Usunennya wikidiv for the help of an operative assistant. "Electronics", 1971 No. 3.
7. Gozling St. Zastosuvannya field transistors. M., "Energy". 1970.
8. De Cold. Vykoristannya diodes for temperature stabilization of the coefficient of strength of the field-effect transistor - "Elektronika", 1971 No. 12.
9. Galperin M.V., Zlobin Yu.V., Pavleiko V.A. M., "Energy", 1972.
10. Technical catalog “New fittings. Polymer transistors. hybrid integrated circuits". View. TsNDI "Elektronika", 74.
11. Topchilov N. A. Hybrid linear microcircuits with a high-resistance input - "Electronic industry", 1973 No. 9.

Kіntsevі cascades pіdsilyuvachіv LF

One-stroke subsidiaries

Single-stroke pilots in lamp priymacha zastosovuyutsya when the exhaust pressure of the troch is more than 4...5 watts. In case of great external strains, the sound of vicarious dvuhіdnі pіdsiluvachі.
The most simple scheme of the terminal cascade - a scheme with a non-intermediate included drive - is directed to fig.1 .

Fig.1

To ensure that the main telephones were not under high voltage, they are often turned on as shown in fig.1 dotted line, and set the anode lance to opir 4.7 ... 10 kOhm.
The biggest expansion of the advantages of end cascades of radio receivers is an electrodynamic receiver based on a sound coil support 3 ... 10 Ohm. Such guchnomovtsі include in the anode lances of the terminal cascades through the output transformer. At this time, electrodynamic generators with a support of 200 ... 800 Ohm are expanded, which can be connected to a power supply without external transformers.

The transformer allows you to change the voltage of the strum, and the value of the support between the windings of the windings. The same cim is explained so widely by the use of transformers in low-frequency power supplies.

Let's assume, for simplicity, that the coefficient of core diameter of the transformer is 100%. Connect the winding w1 of the step-down transformer Tr to the generator of the replacement jet, and connect the winding w2 to the winding 100 Ohm (Fig.2) .

Fig.2

If the generator voltage is equal to 100, and the transformation coefficient n, equal to the ratio of the number of turns of the windings n = w1/w2 = 2, then the I2 strum through the bias R2 and the tension P2 in the bias will be equal:

I2 = U2/R2 = 50V/100Ω = 0.5A
P2 \u003d U2 I2 \u003d 50 V x 0.5 A \u003d 25 W.

If the coefficient of the core diameter of the transformer is 100%, then the voltage intensity is good, as the transformer slows down the generator, so P1 = 25 W. Also, in the generator lance and the windings w1 are more expensive:

I1 = P1/U1 = 25 W/100 V = 0.25 A.

Opіr winding w1 for generator_v dorivnyuє:

R1 \u003d U1 / I1 \u003d 100 V / 0.25 A \u003d 400 Ohms.

Also, opir R1 was four times larger, lower R2. If we repeat the distribution for n = 3, then we take into account that R1 will be 9 times larger than R2, and so on. So you can write:

(1)

In this way, since up to one of the transformer windings is connected to R2, then the other windings for the generator of the chang- ing stream are n at a square times more.

If the transformer is lowering, then more than one and opir R1 go out more than support R2. For moving the transformer, n is less than one and, as can be seen from the formula (1) opir R1, the support R2 should go out less. Since the opir R1 is to lay only the size of the support R2, then it is customary to say that R1 is the opir, guidance or resurfacing to the primary winding.

Vicorist transformers different coefficients transformations can be guided by either more or less than R2.

on the fig.3 shows the most expanded scheme of a single-ended terminal cascade on a promenev tetrode (or a pentad).

Fig.3

The lamp’s orientation is opir guchnomovtsya Gr, resurfacing at the primary winding w1 (or not opir winding w1!). As we have already pointed out, the sound coil of electrodynamic speakers does not exceed 5 ... 10 ohms. Bigness electronic lamps, recognized for operation in the end stages of low-frequency power supplies, showing the maximum tension at values ​​of the input support Ra 2.5 ... 10 kOhm.

The transformation of the low-resistance support of the R2p power switch to the high-resistance support of the input Ra is behind the help of the output transformer.

It doesn't matter if the transformer can be lowered, and the transformation coefficient can be known from the formula (1). For real transformers, the coefficient of core diameter is less than 100%.

(2)

The required number of turns of the secondary winding w2 in the fallow in the support of the sound coil of the speaker is known by the formula:

de w1 - number of turns in the primary winding, shown in table 1.

Table 1

* Pentode part of the lamp.
** The value of the output pressure is indicated with the adjustment of the costs of the output transformer.

In most circuits of terminal cascades on exchange tetrodes or pentodes, a capacitor Csh is connected in parallel to the primary winding. Inode capacitor SSH is switched on between the lamp anode and earth. As it turns out, the sound coil of an electrodynamic speaker is based on a significant world in terms of frequency and it changes with frequency as shown in fig.4.

Fig.4

Approximately for such a law itself, it changes with frequency and reductions to the primary winding of the opir, so that the opir of the winding of the terminal lamp. Change the lamp support to increase the coefficient of non-linear effects.

The opir of the capacitor, as it seems, changes with increasing frequency. Therefore, in parallel with the primary winding of the output transformer, the condenser SSH is turned on in order to ensure that the support of the lamp voltage in the middle of the increased frequency range was left constant. The location of the capacitor Csh is selected at the boundary between 3000 pF and 10000 pF. The working voltage of the capacitor SSH is due to but 2 ... 3 times more than the voltage of the anode life.

Typical values ​​​​of supports near the lance of cathodes for end lamps and the recommended modes of end lamps in tab. one . For lamps 6P1P, 6P6S, the nominal intensity of this support can be not less than 1 W, and for lamps 6P14P and 6P18P - not less than 0.5 W. Bazhano zastosovuvati support with a tolerance of +/- 5%. Capacitor Sk, which blocks the opir of automatic shifting, is to blame for the mother's capacity not less than 10 microfarads for a 6P14P lamp and not less than 5 microfarads for other lamps.

For stable operation of end lamps, the Rc opir in the lantern grid, which controls, is not guilty of overshooting 1 MΩ.

Ultralinear podsiluvach

The main feature of the ultralinear pilot ( fig.5 ) in the presence of a significant field in the fact that the grid of the lamp, which is on the screen, does not come to the plus of life, but to a part of the turns of the primary winding of the output transformer.

Fig.5

Constant voltage on the grids for circuits. fig.3 і fig.5 approximately the same. However, in the scheme of an ultralinear substation, a changeable output voltage must be placed on the grid of the lamp, which is taken from the part of the primary winding between the windings 1-2. At the right choice the lamp mode of the non-linear effect in the terminal cascade is sharply reduced, and the output intensity and intensity change insignificantly.

The frequency response of the power supply with the transformer is shown in the main inductance of the primary winding L1 and the inductance of the difference between the primary and secondary windings of the transformer.
The inductance of the primary winding of the outgoing transformer is chosen so that the inductive support of the winding is larger than the Guchnomovtsya support refurbished into the primary winding. It is easy to beat at medium sound frequencies, at which the frequency response of the cascade is equal ( fig.6 ).

Fig.6

As you can see, with a decrease in the frequency, the inductive winding opir changes, and that is why the opir of the winding is shunted. And changing the support for the vanishing reduces the strength of the lower frequencies. If the inductance of the primary winding L1 of the output transformer is smaller, then at higher fig.6 ).

In real external transformers, in the end, a part of the magnetic power lines, created by a changeable stream, which pass through the primary winding, flashes, passing the turns of the secondary winding. This is the reason for the ranks of the flow of rozsіyuvannya, which does not create a changeable voltage on the secondary winding. At the lower and middle frequencies, the change is insignificant, but at the highest frequencies, the voltage at the voltage changes sharply.

Mentally, it is possible to show a small inductance to the current of the rosette, so the name of the rosette inductance Ls is connected in series with the primary winding of the outgoing transformer. At the lower and middle frequencies, the value of the support of the inductance of the rose is rich less value overexploited support of the advancement. At the highest frequencies, this operation increases and changes the change in the voltage on the primary, and also, on the secondary winding. The greater the flow of the rise, the greater the inductance of the rise, and the greater the frequency response of the booster at higher frequencies (dashed line on fig.6 ).

Changes in the inductance of the rozs_yuvannya reach the relay modifications of the output transformer and the special windings. At the simplest side of the coil, half of the turns of the primary winding are wound, then the secondary and on top of it, a turn of the primary winding is wound. Parts of the primary winding are wound in sequence, so that the first half ends from the cob of the other.

In single-cycle output cascades on lamps, a permanent stream flows through the primary winding of the output transformer, which magnetizes the core of the transformer. Tse to bring up to two unacceptable manifestations.

First of all, the sweating of the pidsiluvach is changing. Therefore, with the same and the same unsatisfactory sweating, the transformer, which works with permanent magnetization, is to blame for the mother great roses lower transformer without magnetization.

In another way, the magnetization of the core with a permanent strum calls for a change in the magnetic penetration of the core material. Reduce the inductance of the primary winding of the outgoing transformer, which will lead to a change in the strength of the cascade at the lowest frequencies, until the appearance of frequency effects.

To weaken the infusion of permanent magnetization, the core should be taken from a gap of 0.1 ... 0.2 mm between W-like plates and jumpers. At the gap, a paper gasket of 0.1 ... 0.15 mm is laid.

Two-stroke pidsiluvach

The principle diagram of a two-cycle pidsiluvach on triodes is directed to fig.7 .

Fig.7

It can be seen from the diagram that the post-storage anode jet of the skin lamp flows through half of the primary winding of the output transformer. Directly, the struma in half of the windings is opposite, and therefore the resulting magnetic field in the core is equal to the equal distribution of fields, created by the skin lamp's jet. With the equal number of turns of the winding halves and the anode jet lamps magnetic fields compensate one for one and the resulting magnetic field in the core is equal to zero. This is one of the most important advantages of a two-cycle scheme.

The presence of magnetization of the core with a permanent strum - permanent magnetization - allows you to choose a core of smaller sizes, lower for single-cycle in subsiluvacs with the same ventilatory tension. Moreover, it is necessary to have a gap in the heart.

On the grids of lamps L1 and L2, two voltages of the same amplitude, but of opposite phases, are supplied (sound from the phase inverter). Therefore, the anode jet of the lamps is also changed by the phases, so if the anode jet of one lamp is increased, the anode jet of another lamp changes ( fig.8 ).

Fig.8

If the oscillators of the half of the primary winding of the output transformer are connected in series, then the changing magnetic field in the core is proportional to the arithmetic sum of the anode streams ( fig.8 c ). Therefore, the voltage on the secondary winding of the output transformer will be twice as much for the voltage, as it would have been with the operation of one lamp.

Just as skin lamps of a two-cycle circuit develop expiratory tension Рvih, then the total exhaustion of a two-cycle circuit is more advanced than 2Рvih. We could have taken the same intensity, yakby switched on two lamps in parallel in a single-cycle circuit, the double-cycle circuit could have a low advantage, the most important of which is the power of the constant magnetization of the core of the outgoing transformer; less non-linear creation with the help of the presence of the twin harmonics.

Subsiluvial cascades can be used in a number of modes, including in the subsilience of LF, the modes of class A, U, AB, AB1, AB2 are vibrated.

Class A mode. The voltage of the voltage on the grids of the lamps - the operating point is sub-class A is selected so that the change in the voltage of the signal on the grids of the lamps does not go beyond the straight line of the grid characteristics of the lamp ( fig.9a ).

Fig.9a

Indicators of subsidence in regimes of class A: small non-linear effects; The anode strum of the calm lamp is larger than the replacement of the warehouse anode strum, after which the coeficient of the core air is small and becomes 30 ... 40%.

Mode class Art. In class B mode, the operating point is selected on the lower edge of the grid characteristics of the lamps ( fig.9b ). With this, the anode stream of a quiet lamp is close to zero, so the anode stream passes through the lamp less if the input voltage is positive. The class mode is zastosuєmo less for two-stroke circuits. In these schemes, the lamps at the shoulders are worked according to their needs: for one hour of one last period of the input voltage, the anode strum passes through one lamp, and for the next hour of the next period - through another lamp.
Pervagoyu mode class є yogo high efficiency. - Up to 60 ... 75%. Slid mother on the vazі, scho for the subsidiaries mode it is not possible to create a shift on the nets of lamps for additional supports in the cathode lance.

Fig.9b

Class AB mode. The class AB mode takes the intermediate position between the modes A and B. The voltage of the displacement on the grid, which controls, is selected less, lower in the lower class B, and more, lower in the lower class A ( fig.9c ). Due to the strength of the weak signals in this mode, they are observed in class A, and the strong ones - in class B. Significantly more, especially with large signal amplitudes, which is stronger. The AB mode is less likely to be achieved in two-stroke subs.

Fig.9c

Substances to the AB mode are subdivided into two groups: AB1, in which the striations are daily, and AB2, in which the robot is affected by the striations. We talked more about different modes for subsidiaries on vacuum tubes, but everything has been said as a whole for transistor subs.

Electric signal switch - ce electronic attachments, the purpose of zbіlshennya sweating, strain chi strumu signal brought to the th input, without the іstotny creation of the th form. Electric signals can be EPC harmonic columbine, struma or tightness, signals of rectilinear, tricutnoi chi and other forms. The frequency of this form of colivan is a significant factor that determines the type of subsidiarity. If the intensity of the signal at the output is greater, lower at the input, then according to the law of conservation of energy pidsilyuvalny attachment it is guilty to include dzherelo kharchuvannya. Including, the energy for the robotic energy supply and the drive to be brought to life. To the same zagalnenu structural scheme pіdsiluvalnogo add-on can be depicted, as shown in fig. one.

1. Structural diagram of the pidsiluvach is outlined.

The electrical coaxing should go to the dzherel signal to the input of the power supply , until the end of which the adventure has come, The energy for robotic support and energy is brought to life from the source of life. Vіd dzherela zhivlennya podsiluvach vіdbiraє natuzhnistі Ro - need to strengthen the input signal. Dzherelo signal for safe tightness at the entrance of the patient R in Exhaust tension R wih seen on the active part of the advancement. Nervousness is seen in patients with tension: R in < R wih< Ро . Otzhe, pidsiluvach- zeroing by input signal reworking the energy of the dzherela of life in the energy of the output signal The transformation of the energy is carried out for the help of auxiliary elements (UE): bipolar transistors, field transistors, electronic lamps, integrated microcircuits (ICCs). varicaps and others.

The simplest pidsiluvach to revenge one pidsiluvalny element. In most cases, one element is deficient, and in the subsidiaries, a sprinkling of active elements is blocked, as if they follow the step pattern: colivannya, strengthened by the first element, go to the entrance of another, then the third, etc.cascade. Pіdsilyuvach is foldedactive and passive elements : up to active elementssee transistors, ate. microcircuits and other non-linear elements that can change the electrical conductivity between the output electrodes under the influence of an electric signal on the input electrodes.barely passivecopsє resistors, capacitors, inductance coils and other elements that form the necessary range of coliving, phase failure and other parameters of strength.In this way, the skin cascade of subsidiaries is formed from the minimum necessary set of active and passive elements.

Structural diagram of a typical bagatokaskadny pіdsilyuvacha induced in fig. 2.

2. Scheme of a multi-cascade pidsiluvach.

Input cascade і front pidsiluvach are used to strengthen the signal value, which is necessary for the supply of tension to the input of the patient (exit cascade). The number of cascades of the front building is assigned to the necessary buildings. The input cascade ensures, at the time of consumption, the use of the signal, the noise parameters, and the necessary regulation.

exit cascade (cascade of intensity of tension) of appointments for the delivery of a predetermined tension to the signal with minimal effects of yogo form and maximum CCD.

Dzherelami posilyuvanikh signals You can have a microphone that reads the heads of magnetic and laser storage devices, various conversion of non-electrical parameters into electrical ones.

Navantagenyam є power generators, electric motors, signal lamps, heaters, etc. Dzherela life oscillate the energy from the given parameters - the nominal values ​​of the voltage, flow and tension. Energy is spent in the collector and base tubes of transistors, in the fire tubes and the anode tubes of the lamps; vikoristovuєtsya for podtrimki zadah modesіv roboti elementіv podsilyuvacha ta navantazhennya. Often the energy of life is needed for the conversion of input signals.

Classification of subsidiaries.

Subsidiary outbuildings are classified according to different signs.

per mind stronger electric signals pіdsilyuvachi subdіlyayat pіdsilyuvachi harmonious (uninterrupted) signals and subdued impulse signaling

According to the width of the smuga, the transmission and the absolute values ​​of the frequencies of the subsidiaries are divided into the following types:

- Pіdsilyuvachi postіy strumu (UPT) used for strengthening signals at the boundary at the lower frequency = 0 to the upper operating frequency. UPT will help to change the warehouse signal, and yogo post warehouse. UPT is widely used at the attachments of automation and computational equipment.

- Supplementary voltages, their line is subdivided into low, high and low high frequency.

By width smughi pass different frequencies are divided:

- choice podsilyuvachi (podsilyuvachi high frequency - UHF), for any valid frequency /1 ;

- wide range pіdsilyuvachi with a great range of frequencies />>1 (for example, ULF - a low-frequency substation).

- Pіdsylyuvachi - terminal cascade of ULF from transformer rozvyazkoy. In order for the tightness to be maximum R int. before= R n, tobto. opіr navantazhennya can add to the internal support of the collector lance of the key element (transistor).

per constructive pіdsilyuvachі can be pіdrozdіlі on large groups: pіdsilyuvachi, vykonanі s dpomogoyu discrete tekhnologii, so by the method of hanging chi drukovanogo montage, i іdsilyuvachi, vykonanі z іdpomogoyu іintegralnoї tekhnologii. In this day and age, analog integrated microcircuits (ICCs) are widely used as active elements.

Indicators of work and pіdsilyuvachіv.

Before showing the work of the pilots, the input and output data, the strength coefficient, the frequency range, the efficiency coefficient, the KKD and other parameters that characterize this operational power are taken into account.

Before incoming tribute the nominal value of the input signal (voltage Uin= U 1 , struma Iin= I 1 or tightness Pin= P 1 ), input opir, input capacitance and inductance; they signify the applicability of a podsiluvach for specific practical zastosuvans. EntryopirRin at the por_vnyannі with the support dzherel signal Rі determines the type of subsidiaries; fallow in the їх spіvvіdnennia razrіznjayut pіdsiluvаchі naprugi (when Rin >> Rі), pіdsiluvachi struma (with Rin << Rі) or pіdsiluvаchі vagusі (when Rin = Rі). Inhіdna єmbrushW input, being a reactive component of the support, it directly flows into the width of the operating frequency range.

Weekly data - nominal value of output voltage U twist \u003d U 2, struma I vor = I 2, Exhaust tension P twist \u003d P 2 and out of the way support. The last opir can be significantly smaller, the lower opir of interest. І input and output supports can be active or reactive warehouse (inductive or mnіsnu). In a wild type of skin, they have a new support Z, which is both active and reactive warehouse

Strength coefficient called the extension of the output parameter to the input parameter. Differentiate the coefficients of strength for the voltageK u= U 2/ U 1 , behind the strum K i= I 2/ I 1 that tightness Kp= P2/ P 1 .

Characteristics of the pidsiluvach

Characteristics of the podsilyuvacha vodobrazhayut yogo zdatnist posilyuvaty with the first step of accuracy signals of different frequency and form. To the most important characteristics lie amplitude, amplitude-frequency, phase-frequency and transition.

Rice. 3. Amplitude characteristic.

Amplitude characteristic - the presence of the amplitude of the output voltage as the amplitude is applied to the input of the harmonic oscillation of the singing frequency (Fig. 3.). The input signal changes from the minimum to the maximum value, and the value of the minimum value is responsible for overriding the value of the internal transitions UP , which are created by the pidsiluvach himself. In an ideal substation (subsilience without shifting codes), the amplitude of the output signal is proportional to the amplitude of the input U vortex= K*Uin that amplitude characteristic may look like a straight line that passes through the cob of coordinates. In real pіdsiluvachakh pozbutisa pereshkod not vdaєtsya, so yogo amplitude characteristic vіdrіznyаєє vіd pryaї.

Rice. 4. Amplitude-frequency characteristic.

Amplitude-і phase-frequency Indicators indicate the fallowing of the coefficient of strength in the frequency. Due to the presence of reactive elements in the substation, the signals of different frequencies are not equally strong, and the external signals are heard according to the input different frequencies. Amplitude-frequency The characteristic of the fallow land is represented by little 4.

Working frequency range podsilyuvacha name the frequency interval, between which the module of the coefficient K zalishaєtsya postіynym or change at the back of the tasks of the borders.

Phase frequency the characteristic is the frequency delay of the cut of the phase of the output signal to the exact phase of the input.

Zvorotni zv'yazki have pіdsiluvachakh.

Zvorotny zv'azk (OS) call the link between electric lances, for additional energy, the signal is transmitted from the lance with a higher level signal to the lance with the lower yogo line: for example, the lateral lance is pidsilyuvacha at the entrance or from the forward cascades. Structural diagram of the pіdsilyuvacha іz zvorotniy zvorotnym zv'yazyk is depicted small 5.

Rice. 5. Structural (left-handed) principle scheme with negative OS along the strum (right-handed).

Transmission of a signal from the exit to the input of the subsidiaries Art. Chotirohlyusnik zvorotnogo zv'azku є zvnіshnіm elektrichnіm lanzug, scho sho z passive or active, linear or non-linear elements. As if the zvorotny zv'azok suffocates the whole podsiluvach, then the zvorotny zv'azok is called common: yakscho zvorotny zvorotny vyazok ohoplyuє okremі cascades or parts of pіdsilyuvacha, called miscevoj. In such a rank, a structural diagram of a pidsiluvach is presented to the little one with a zagalny zvorotny zv'yazkom.

The model of the subsiluvial cascade.

Pidsilyuvach ny cascade - a constructive plan for subsidiarity is to take one or more active (susceptible) elements and a set of passive elements. In fact, for greater precision, folding processes are carried out on simple models.

One of the variants of the transistor cascade for strengthening the changeable strum is aimed at the little zliva. Transistor V1 r-p-r type of inclusions according to the scheme with a hot emitter. The input voltage base - the emitter is created with a dzherel from the EPC E c that internal support Rc dzherela. Resistors are installed at the lanceuzi base R 1 і R 2 . Transistor collector E to through resistors R beforeі R f. The output signal is received from the connections of the collector and the emitter and through the capacitor Z 2 arrive at the edge R n. Capacitor SF double with resistor Rf satisfy RC -lanka filter ( positive return call - ПІС), which is necessary, zokrema, for smoothing out the pulsation of the pressure of life (with a low-pressure neck E to with a great inner support). Also, for greater stability, I will add a transistor emitter to the lance V1 (negative return call - OOS) can be additionally turned on RC -filter, which will retransmit part of the output signal back to the input of the signal. In this rank, you can overcome the effect of self-excitation by building it. Sound made by piece zovnishnya environmental protection allows you to reach good parameters of the bass, however, it is true in the wild type only for strengthening the steady stream or low frequencies.

Low-frequency power supply circuit for a bipolar transistor.

Subsiluval cascade on a bipolar transistor, connected behind the circuit with OE, is one of the widest asymmetric subsidiaries. The principle diagram of such a cascade, vikonan on discrete elements, is shown below.

This circuit has a resistor Rk , inclusions in the head lance of the transistor, to serve as an exchange for the collector stream, and to ensure the necessary coefficient of strength. For help dilnik voltage R1R2 the voltage is set to be adjusted to the VT transistor, which is necessary for the class A strengthening mode.

Lanzug Rece vikonuє function of the emitter thermal stabilization of the rest point; capacitors Z 1 і C2 є razdіlnymi for postіynoї and zminnoї warehousing stream. Capacitor Se shunt resistor Re behind the change strum, shards Se significant.

When the input voltage is applied to the signal of a constant amplitude at different frequencies, the output voltage in the fallow frequency changes, the shards of the opir capacitors C1 , C2 at different frequencies differently.

The dependence of the coefficient of strength on the frequency of the signal won the name amplitude-frequency Indications of a pidsiluvach (AFC).

Low frequency subdues most widely get stuck in order to strengthen the signals that carry sound information, in these cases, stench is also called subsonic sound frequency, the Crimean ULF is victorious to strengthen the information signal in various areas: viruval technology and flaw detection; automation, telemechanics and analog computing equipment; at other electronics galuzahs. The sound frequency subduer sounds add up front podsiluvach і pіdsiluvаcha vagueness (Rozum). Front pidsiluvach applications for increasing the tension and tension and bringing them to the values ​​required for the work of the terminal tension relief, often including the volume controls, the timbre or the equalizer, and sometimes it can be constructively vikonaniya like an okremiya attachments.

Pіdsilyuvach natuzhnostі is guilty in the colo navantazhennya (spozhivacha) set the tension of electric coliving. Some ideas can be used to enhance the sound: acoustic systems (speakers), headphones (headphones); radio broadcasting device is a radio transmitter modulator. The substation of low frequencies is an invisible part of all sound-creating, sound-recording and radio-transmitting equipment.

The analysis of the work of the substation cascade is carried out for an additional equivalent circuit (in the figure below), in which the transistor is replaced by a T-like substitution circuit.

In this equivalent circuit, all physical processes, which are used in transistors, rely on additional low-signal H-parameters of the transistor, pointing lower.

For the life of the subsidiaries, the vikoristovuyutsya dzherela naprugi with a small internal support, you can decide what the resistors are to the input signal R1 і R2 connected in parallel and їх can be replaced by one equivalent Rb \u003d R1R2 / (R1 + R2) .

An important criterion for the selection of nominal resistors Re, R1 і R2 є ensuring the temperature stability of the static mode of the transistor. The value of the parameters of the transistor, depending on the temperature, should be brought to a non-ceramic change of the collector jet. Ik , in the aftermath of which non-linear spoofing signals can be blamed, which are being strengthened. To achieve the best temperature stabilization, the regime needs to increase the operating Re . However, it is necessary to increase the pressure of life to the point of necessity E and zbіshuє spozhivanu vіd nіgo tuzhnistі. When changing the support of the resistors R1 і R2 the tension is also increased, which reduces the economy of the circuit and changes the input support of the auxiliary cascade.

Pidsilyuvach postiynogo strumu in the integral vikonnі.

Pidsilyuvach (OU) in the integrated viconan є the widest universal microcircuit (ІС). OU - ce attachments with highly stable indicators, as they allow to carry out the processing of analog signals according to the algorithm, which is set for the help of the old lancers.

Operatsiyny pіdsilyuvach (UU) - unification bagatokaskadny pіdsiluvach postіy strumu (UPT), which helps to advance the power to the electrical parameters:

· Coefficient of strengthening on the pressure of the load to inexactitude;

· Vkhіdniy opіr pragne to neskіchennostі;

· Exit opir pragne to zero;

· If the input voltage is equal to zero, then the output voltage is also equal to zero Uin = 0, Uin = 0;

· Neskіchenna smuga posilyuvanih frequencies.

The OU can have two inputs, which are inverted and non-inverted, as well as one out. The input and output of the UPT is conjured up to the mind of the dzherel signal of the current tension (asymmetric, symmetrical) and the values ​​of their supports. In case of rich fluctuations in the UPT, like in the subsidiaries of the changing struma, secure the great input opir, so that you change the inflow of the UPT to the core signal, and the small outward opir, in order to change the influx of the influx of the outgoing signal of the UPT.

On little one 1, a scheme of a pilot is induced, which is inverted, on little 2, a non-inverter. In this way, the coefficient of strength is good:

For inverting Кіо = Rос / R1

For non-inverted Knou = 1 + Roc / R1

Pіdsilyuvach, scho іnvertuє, ohopleny OOS parallel for naprugoyu, scho calls for a change Rinhоu і Ryhоu. A non-inverting booster of the OOS surges following the voltage, which ensures the improvement of Rinhou and the change in Rvihou. For subbags of these op amps, you can induce different circuits for analog signal processing.

Before the UPT, the highest possible support is presented. The mimovilna change of the output voltage of the UPT with a constant voltage of the input signal is called drift . The reasons for the drift are the instability of the voltage of the circuit, the temperature and time instability of the parameters of transistors and resistors. Tsim can satisfy the OS, in which the first cascade of selections for the differential circuit, which takes into account all in-phase transitions and secures the high input opir. This cascade can be selected on field-type transistors and warehouse transistors, de-emphasizing (turning) GTS connections (stable stream generator), which can suppress common-mode transitions. To move the inlet, the support should be installed with a deep last OOS and a high collector pressure (at times Jinhou is equal to zero).

Substances of a steady stream are recognized for strengthening signals, which change regularly in the hours that signals, the equivalent frequency of which approaches zero. That UPT is due to the mother amplitude-frequency characteristic at the sight, the image of the little one is angry. Since the coefficient of strength of the OU is already great, then the victoriousness of the OU is more likely to be possible when it is stunned by a deep negative turning signal (with the presence of the OOS, wind an extremely small signal to "noise" at the input of the OU to give the output of the OU a voltage, close to a voltage).

The history of the operational substation is explained by the fact that the subsistences of the steady strum were used in analog calculation techniques for the implementation of various mathematical operations, for example, subsuming, integrating and other. .

Subsidiary tension.

What do you show yourself pіdsilyuvach- Dali, for the sake of style, will we call Yogo ROZUM? From the vishchevyladeny, the block diagram of the pidsiluvach can be mentally divided into three parts:

• Input cascade
• Intermediate cascade
• Exhaust cascade (pain relief)

All these three parts beat one task - to increase the intensity of the output signal without changing its shape to such a level that it is possible to increase the tension with a low support - the dynamic head of the headphones.

Buvayut transformerі transformerless ROZUM schemes.

1. Transformer subdued tension

Look at single stroke transformer ROSUM, In which the switching transistor is behind the circuit with OE (Fig. Zliva).

Transformers TP1 and TP2 are designed for utilizing the input power supply support and the input power supply support with the support for the input signal. Elements R and D ensure the primary operation mode of the transistor, and the largest change in storage, which should go to the transistor T.

Oskіlki transformer is not an important element of the pressure, because maє large dimensions and vaga, visibly foldable at the ready, then in denmark the hour of the greatest width of the nabul transformerless pіdsiluvаchі poguzhnostі.

2. Beztransformatorny pіdsilyuvachi potuzhnostі.

Look at two-stroke ROZUM on bipolar transistors with a different type of conductivity. As it was planned more, it is necessary to increase the intensity of the output signal without changing its shape. For which one is taken the constant stream of life ROZUM and is transformed into a change, but so that the shape of the signal at the output repeats the shape of the input signal, as shown in the small picture below:

Just as transistors can achieve a high value of steepness, then it is possible to create circuits that work on the voltage of one ohm without the need for transformers. There is such a podsiluvach in the form of a bipolar dzherel of life from a grounded middle point, although it is possible to induce schemes for unipolar life.

Schematic diagram of complementary emitter repeater - pіdsilyuvacha z dodatkovoy symmetry - brought a little evil. With the same input signal through the n-p-n-type transistor, a stream flows for an hour of positive periods. If the input voltage is negative, the stream will flow through the p-n-p-type transistor. Combining the emitters of both transistors, navantazhuyuchi їkh zagalnymi navantagenі and giving the same signal to the combined base, otrimuєmo dvuhtakny cascade of strengthening the potency.

Let's take a look at the report on the inclusion of transistors in the robot. Transistors of the power supply are used in class U modes. In this scheme, the transistors are absolutely the same for their parameters, but for the planar structure. When there is a need for positive pressure on the input Uin transistor T1 works in power mode, and the transistor T2 - in the regime of vіdsіchennya. When necessary, negative napivkhvili transistors change roles. Since the voltage between the base and the emitter of the open-circuit transistor is small (about 0.7 V), the voltage Uvix close to pressure Uin . However, the output voltage is created through the influx of non-linearity of the input characteristics of transistors. The problem of non-linear creations is overcome by the supply of a cob shift on the base lines, which translates the cascade into the AB mode.

For the booster, as you can see, the maximum possible amplitude of the voltage on the tension um dorivnyuє E . Therefore, the maximum possible tension of vanity is shown by viraz

It is possible to show that at the maximum pressure of tension, the tension is reduced in the presence of life tension, which is indicated by the virus

Vihodyachi from what has been said, we take as much as possible coeficient of brown dії ROZUM: nmax = P n.max/ P consumption max = 0,78.

Outdoor cascades on the basis of "dviyok"

As a signal, we will vicorate the generator of a replacement stream with an external support, which is re-energized (from 100 Ohm to 10.1 kOhm) with a 2 kOhm coil (Fig. 3). In this way, when testing the VC with the maximum output support of the generator (10.1 kOhm), we will, for the most part, bring the robotic testing mode of the VC to the circuit with a closed OOS, and in the other (100 Ohm) - to the circuit with a closed OOS.

The main types of warehouse bipolar transistors are shown in fig. 4. Most often in the VC, there is a double-stacked Darlington transistor (Fig. 4 a) based on two transistors in one conductor ("dvіyka" Darlington); more conveniently - a Bryston warehouse transistor (Bryston, Fig. 4 c).
"Diamond" transistor - a different type of folded transistor Shikla - indications in fig. 4 p. On the view of the Shiklai transistor, which transistor has a "strum mirror" strum collector in both transistors VT 2 and VT 3 may be the same. In some cases, the Shikla transistor will have a transmission coefficient greater than 1 (Fig. 4e). І here K P \u003d 1 + R 2 / R 1. Similar circuits can be taken in field-effect transistors (PT).

1.1. Exterior cascades with improved "dviyok" . "Dviyka" - a two-stroke output cascade with transistors connected behind the Darlington circuit, Shikla chi yogo combination (quasi-complementary cascade, Bryston and others.). A typical two-stroke output cascade on the Darlington "dvіytsі" of indications in fig. 5. If the emitter resistors R3, R4 (Fig. 10) of the input transistors VT 1, VT 2 are connected to the adjacent busbars, then these transistors will operate without a stream, then in class A mode.

We wonder what the pairing of external transistors for the "Darlingt" twin will give (Fig. 13).

On fig. 15 shows a diagram of VK, vikoristan in one of the professional subsidiaries.

Mensh is popular with VK scheme Shikla (Fig. 18). Recently, the development of transistor UMZCH circuitry was popular with quasi-complementary output cascades, if the upper arm followed the Darlington circuit, and the lower one - behind the Shikla circuit. However, in the open version, the input support of the VK shoulders is not symmetrical, which leads to additional creations. A modification of such a VC with a Baksandall diode, as a base-emitter switch of the transistor VT 3, the indications in fig. twenty.

Krіm looked at "dviyok", є modification of VC Bryston, in the same input transistors, the emitter strum is used as transistors of the same conductivity, and with the collector strum - transistors of the same conductivity (Fig. 22). An analogous cascade can be implemented on field transistors, for example Lateral MOSFET (Fig. 24).

A hybrid output cascade behind the Shikla circuit with field-operated transistors is shown in fig. 28. Let's take a look at the scheme of a parallel switch on field transistors (Fig. 30).

As an effective way of promoting and stabilizing the input support of the "dvіyka", it is recommended to vicorate a buffer at the input, for example, an emitter repeater with a jet generator in the emitter's lance (Fig. 32).

From the sight of the "doors" the largest in terms of phase deviation and smoothness of transmission appeared VK Shikla. We wonder what can be given to such a cascade of buffer blocking. If you replace one buffer by switching two on transistors of different conductivity, connected in parallel (Fig. 35), then it is possible to increase the further expansion of parameters and move the input support. From the most examined two-stage circuits, the Shikla circuit with field transistors showed itself the best for non-linear creations. Let's wonder how to install a parallel buffer on the її input (Fig. 37).

The parameters of the last output cascades are listed in Table. one .

The analysis of the tables allows the generation of the following statements:
- whether it be a VC with "dviyok" on BT, as a navantazhennia UN is badly suitable for work in the UMZCH of high fidelity;
- the characteristics of the VC from the PT at the exit are not enough to lie in the support of the signal;
- a buffer cascade at the input, whether it be from "dviyok" on the BT, moving the input opir, lowering the inductive warehouse output, expanding the bandwidth and making the parameters independent of the output support of the signal;
- VK Shiklaj with FET at the output and a parallel buffer at the input (Fig. 37) has the best characteristics (minimum sound, maximum bandwidth, zero phase deviation at the sound range).

View cascades on the basis of "triyok"

High-power UMZCHs often have three-cascade structures: Darlington triplets, Shikla with output Darling tone transistors, Shikla with output Bryston transistors and other combinations. One of the most popular external cascades in Denmark is the VC based on a storage Darlington transistor with three transistors (Fig. 39). On fig. 41 indications of VC with cascading of cascades: the input repeats at the same time on two cascades, yak, at its own edge, also pratsyuyut on two cascades of leather, and the third stage of inclusions on the open air. As a result, at the output of such a VC, several transistors are used.

The circuit of the VK, in yakіy yak vihіdnі transistors vikoristanі storage darlington transistors, is shown in fig. 43. The parameters of the VC in Fig. 43 can be significantly changed, so that you can turn on the input well by recommending a parallel buffer stage with the "twos" (Fig. 44).

VK Shikla's variant behind the scheme in fig. 4 g of stacked Bryston transistor readings in fig. 46 . On fig. 48 readings of the variant t VK on Shikla transistors (Fig. 4 e) with a transfer coefficient of close to 5, in which the input transistors work in class A (thermostabilization lances are not shown).

On fig. 51 indications of the VC with the structure of the forward circuit only with a single transmission coefficient. A glance will be inaccurate, otherwise it will look like a diagram of the output cascade with the correction of the non-linearity of Hawksford (Hawksford), pointed at fig. 53 . Transistors VT 5 and VT 6 are storage Darlington transistors.

We replace the output transistors on the field transistors of the Lateral type (Fig. 57

For the increase in the reliability of the subsiluvacs for the switching off of the open streams, which are especially unsafe when clipping the high-frequency signals, the circuits of the anti-intensity of the high-frequency transistors are adopted. Variants of such solutions are shown in fig. 58. Through the upper diode, the base stream is thrown off into the collector of the transistor when the voltage is close to the voltage. On the voltage of the strained transistors, the sound is in the range of 0.5 ... 1.5, which is approximately equal to the voltage drop on the base-emitter transition. In the first variant (Fig. 58 a), the voltage of the emitter - the collector does not reach the voltage value of approximately 0.6 V (voltage drop on the diode) behind the horn of the additional diode in the lancet base. Another circuit (Fig. 58b) allows selection of resistors R 1 and R 2. Analogous solutions to stop at the power keys.

Often, in order to increase the power in the UMZCH, it is necessary to work out a separate meal, increase, by 10 ... 15 V for the input stage and a voltage boost and a decrease for the output stage. For this reason, in order to avoid the output of the fret of the output transistors and to reduce the vanity of the forward ones, it is necessary to switch the diodes. Let's take a look at this option with the example of modifying the circuit in fig. 39. At the time of the input voltage increase, the voltage of the output transistors is higher than the voltage of the output transistors, the additional diodes VD 1, VD 2 (Fig. 59), and the input stream of the base transistors VT 1, VT 2 are thrown onto the bus of the terminal transistors. In this case, it is not allowed to increase the input voltage more equal to the voltage for the output stage of the VC and the stream of the collector of transistors VT 1, VT 2 is reduced.

Usunennya schemes

Previously, with the method of simplification, the replacement of the scheme of displacement in the UMZCH was victorious around the core of the tension. Lots of different circuits, circuits, output cascades with a parallel repeater at the input, do not require circuits for sound, which are additional advantages. Now let's take a look at typical wiring diagrams, as shown in fig. 60, 61.

Generators of a stable stream In modern UMZCH, a number of typical schemes are widely used: a differential cascade (DK), a vibrating strum (a "strum mirror"), a scheme for zsuvu equal, a cascode (with subsequent and parallel eating, the rest is also called a "lamani cascode"), a generator of a stable struma (GTS) and others. Їх correctly zastosuvannya allows you to significantly improve the technical characteristics of the UMZCH. The estimation of the parameters of the main schemes of the GTS (Fig. 62 - 6 6) is carried out for additional modeling. It seems that the GST is for the purposes of the UN and inclusions in parallel with the VC. Doslіdzhuєmo yogo authority for additional methods, similar to the doslіdzhen VK.

Vidbivachi Struma

Examined schemes of the HTS - tse variant of dynamic navantazhenya for single-cycle UN. In UMZCH with one differential cascade (DC) for the organization of a zustrіchny dynamic navantage in the UN, the vicorist structure of the "strum mirror" or, as it is also called, "strum strum" (VID). The structure of the UMZCH was characteristic of Holton, Hafler and others. The main schemes for vibrating the struma are shown in fig. 67 . The stench can be either with a single transmission coefficient (more precisely, close to 1), or with a larger or smaller one (large-scale vibrating struma). In the case of the voltage booster, the voltage of the strum VID is in the range of 3 ... 20 mA: Therefore, everything VID with a strum, for example, is close to 10 mA for the circuit of fig. 68.

Results viprobuvan induced in the table. 3 .

As a butt of a real patient, the S. BOCK scheme of the patient is propagated, published in the journal Radiomir, 2011 No. 1, p. 5 - 7; No. 2, p. 5 - 7 Radiotechnika №№ 11, 12/06

By the author's method, Bulo pobudov pіdsilyuvacha poguzhnostі, adventitious like voicing "space" at the hour of the front entrances, so discos. Obviously, I wanted to, that the wines were killed in the case of small dimensions and easily transported. Another benefit to the new one is the availability of components. To reach the Hi-Fi quality, I chose the complementary-symmetrical scheme of the output cascade. The maximum output power of the pilot was set to 300 W (at 4 ohm input). With such tension, the output voltage should become approximately 35 V. Also, for UMZCH, a bipolar voltage of life in the boundaries of 2x60 V is necessary. one . UMZCH may asymmetric entrance. The input cascade is made up of two differential inputs.

A. PETROV, Radiomir, 201 1 , Nos. 4 - 12