DE2038354C - Power amplifier for both underwater telephony and echo sounding - Google Patents

Description

2. power amplifier according spoke 1, characterized in that the driver and Control device (26) the amplifier stage (28) corresponding to a section of the input period in a saturation range a cut-off angle between 20 and 40 °.

3. Power amplifier according to claim 1, characterized in that the driver and Control device (16; 26) is selectively controllable in order to have a substantially constant output power corresponding to a cut-off angle range between 20 and 40 °, essentially constant ^ ^Bt

ok Transistor amplifier-S of sinusoidal Si

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4. Power amplifier according to claim 1, da- (German Auslegesch characterized in that the power amplifier 30 PaieDtschnft 34V where). _g r (2.feinVollbrückenve _IS tärkerderK, _aSS eB J * fi ^ ffi

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The invention relates to a power amplifier for both underwater telephony for the Echo sounding, in which the output power is reduced to a 4 » narrow frequency range is concentrated

The output amplifier stages for the transmitter of a sonar system are typically designed to operate in an operating area where the

wSerSnie and echo sounding too *

a very high output power Provide efficiency in converting DC xome energy ta acoustic energy, with minimal generation of harmonics or harmonics

can. kt measurement amplifier the

initial ^ the previous one at least one V Tax income Amplifier stages

emer

oVt that little-

the for

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«SSto will. However, it was inevitable that the actual effective operating efficiency must be reduced during echo sounding. Alis for this reason a pure switching operation has been provided for the echo sounding, so with the output variable or the transmitted variable consisted of a rectangular figure. However, such a rectangular wave has an increasing slope a growing number of harmonics or harmonics, which, however, effectively veriorengehen for the echo sounder, since the receiving device only one Can process limited bandwidth or is narrow-band and the comparatively high frequency Can no longer capture harmonics or harmonics pure switching operation for echo sounding still suffers from the problem of poor efficiency and, moreover, was with the pure see 20 and 40 drives

By the present £! 8 Power amplifier created that

for underwater telephony or f & ßto ^ _m , thereby providing for> ernal output power in both concrete ranges, and for a very high level of efficiency, constant amplifier performance and minimal generation of ^

waves or harmonics of the exercise «^ range lies between the linear »: area and the pure ^ * ^ ** «« ^ J £ by not only does one get the advantage that one and the same performance is available for both operating modes amplifier can use, but also we Kungsgrad is significantly improved in both modes, especially for the echo sounder is improved, since one during the operation of the

³ 4

Power amplifier in the oversteering range is not a linear transistorized push-pull power

^m? ..SLSK ^? ^tedhcit «» «" gt. «Me for an amplifier 10 connected to a DC power supply

^re 's? ? S ^ ^l ^ ^eb vo ^ esehen wiid. _que n _e u is connected by an oscillator 14

u η R? · Λ embodiment is driven forward, which has a sinusoidal output variable

sent, aau qie! reiber- and control device 5, which with the help of the input potentiometer

is selectively controllable to a substantially con- 16 is changeable The output variable of the amplifier

A constant output power corresponding to a cut-off device 10 arises over the loading device 18.

angle between 20 and 40 °, essentially con- If the slide on potentiometer 16 is

constant output voltage corresponding to a nearly shift that the input variable in the

pure icnaltbetneb, or linear mode of operation before- io amplifier increased, then a point is reached at

watch. ^ _1n ^ _eT amplifier _eme maximum not yet

The power amplifier can expediently generate a trimmed sinusoidal output variable that of Class B full bridge amplifier. the input waveform is reproduced. Whom? then In the following, the invention is based on the input variable is increased further, then the Embodiment with reference to the drawing 15 output variable on Grand of the power supply

explained in more detail. It shows borders and appears in the form of a trimmed

F1 g. 1 is a schematic diagram of a grand waveform such as that shown in FIG. 1 a is shown. laying Gegentaktverstärk eranordnung, the check so the input waveform is sinusförmg, which can be OFF-controlled, but that it is in gangswellenfonn Übcrsteuerangs- more or less operates abber calibration, capped _Μ, which depends on the degree of overdrive

F i g. Fig. 1 a is a graph which is FIG. This degree of oversteer is shown in FIG. 1 a through

typical mode of operation in the overdrive range illustrates the angle of the input shaft B _c , at

illustrates what the cutting off or limiting of the

F i g. 2 a graphic representation of a typical output variable «* due to the power supply begins,

characteristic curves of an amplifier that is used both in this angle! should be referred to as a cut-off angle

will work linearly as well as in the overdrive area,

can »E ₅ ^ t advantageous, the mode of operation of the device

Fig. 3 is a graph showing the tang of Fig. 1 with extreme changes in loading Basic efficiency (??,) and the total efficiency load impedance, as shown in FIG. 2 is shown to be

See degrees (η _τ ) as a function of the trimming angle θ 3o. If the input variable is on a con

time ¹ ; constant value is maintained and if the load

F i g. 4 a block diagram of a typical sonar impedance 18 is reduced, then the transmitter, in which the present invention is proportional to the input line, since the transistor is used, acts more strongly like a constant current source and there

Figure 4a is a graphical representation of a waveform typical of the output impedance of the transistor stage

form of the output of FIG. 4, is very much higher than the load impedance

Fig. 5 is a block diagram of a transmitter arrangement (assuming a common emitter, which illustrates the manner in which the connection is made in the case of negative feedback), a variety of similar amplifier stages to this Assuming that the load impedance can be used to increase the total amplifier 40 and indeed to an extremely high value, to change power, when using the same so that one approaches the condition of an open current input stage, circuit, then the amplifier works in one

Fig. Sa is a graph showing the off-limiting operation, this operation being very similar to the output characteristics of the device of FIG. 5 is similar to square wave switching operation. The illustrated, both in the linear B class 45 then works more like a constant voltage operation and in the overdrive range, source for a given input driver size and

F i g. 6 a schematic circuit diagram of a typical the output energy is reversed the load B-class amplifier, in which the present impedance values are proportional,

finding is applied, between the linear B-class mode of operation and

7 shows a schematic circuit diagram of another 50 of the switching mode of operation, the output B-class amplifier, in which the present invention is applied via a reversal point of maximum conductivity, achieves performance. This is the area where the performance

8 is a schematic circuit diagram of an amplifier intended to work. Within this area

module of the type which, when arranged, generates the amplifier up to 2.1 db higher basic

according to FIG. 5 can be used, 55 output power than the maximum not capped

F i g. 9 is a schematic circuit diagram of an amplifier output variable from a class B stage.

module similar to that of FIG. 6, which is given each time. This increase in output power

but being operated by a single source of energy will be carried out at the same time as the proportional reduction

can and a compensation device for the amplifier losses achieved, so that such a

Has power supply voltage fluctuations, 60 amplifiers are very advantageous and desirable,

and in this way can be a directional

F i g. 10 to realize a schematic circuit diagram of a typical amplifier which is both selective as

see driver amplifier, such as that in Fig. 7, B-class amplifier in the linear operating range or

a short-circuit limiting device can work in the overdrive range and itself

shows. 65 can be used advantageously, such. B. at the

The override concept can best be used with water telephony, it also has a high gain

make it understandable, by setting up an arrangement for efficiency and also a high level of stability.

seeks, as shown in FIG. 1 is illustrated in the quality for high performance echo sounders. There no

5 6

Disadvantages arise when you can provide signals with a higher level up to the vicinity and the Switching operation overridden, you do not need to feed amplifier 28, so that this in the over-switch devices is driven with high switching speed control range, as is exemplary and the output variable is inherently free from wise by the third (capped) period Switching transitions. 5 F i g. 4 a is illustrated.

Fig. 3 shows a diagram, Fig. 5 is a block diagram of a transmitter arrangement

Relationship between the overall efficiency (η _τ ) voltage is shown in which way a multiple and the efficiency at the fundamental frequency (7, 7,), number of similar amplifier stages used for a cut-off angle 0 _C shows. The total can, in order to increase the total amplifier ^energy to efficiency, can change as the ratio of output I0, using the same input power P ₀ across a resistive load to the middle step. A variable voltage source 34 is to be defined at an input DC power P _1. The spannungsgesieucrten oscillator 36 connected to basic efficiency is defined as the ratio of the output of which is a sinusoidal AC-ground output power Pf to the average input ^tr om with a frequency defined in accordance with the DC power P. ₁ ^l 5 input voltage V, changes. This initial

In this graphic representation, the cut-off variable is applied to an amplitude modulator 38 characteristic of the switching leads, which has an additional input and operates and fed at a cut-off angle of 90 ° from a variable control source 40, the amplifier operates in the linear B- Class-will that have the linear property according to the operation. Here reached the overall efficiency, in the ² ° associated small diagram, and in modulated in the vicinity of a Abkappwinkels of nearly ^{zero, the} output signal from the oscillator 36, almost 100% of the basic efficiency is, however, ^w of the substantially reduced i ^e in accordance with the waveform at the output, due to the Fre amplitude modulator 38 is shown. This modulus harmonic, the signal lated in the switching mode, is generated as an input variable. When the trimming angle increases, ^a 5 driver amplifier 42 is input, which in turn is a. then the base efficiency increases significantly to driver input to each of three amplifiers and maintains a high value over a 44, 46 and 48 provides. These amplifiers are also ranges from B _c , such as e.g. B. between 20 and 40 °. Here ⁸ P ^e> nc DC power supply 50 is connected and can be seen that the amplifier has a basic ^{s' s} work so that they power up to a Bcwirkungsgrad of 78.5% in the linear mode 3 "lastungwon ichtung 52 Make that also an electrical and 81.1% with full switching operation. Can be between troacoustic transducers. The output of these operating states reached the base of the amplifiers 44, 46 and 48 similar efficiency can be nearly 89%, which is higher than one of the ones shown in Fig. 5a, called linear B-class operation or its switching operation of the ^cm section of the lower range from 0 to V " _s Hegt. 35 is a faithful reproduction of the input signal,

Fig. 4 shows a block diagram, however, a typical ^wcnn the Trciberspuimung increases, and z "ar sonar transmitter and this can be both ^{u" it} in the linear these degrees, thin is the output waveform B-Klassenbelriebsbereich as well as more and more capped in the overdriving of the separate amplifier Assigned clock signals from ^what represents an operation in the upper control area, a clock generator 10, which is a counter or a main 40 where the (! wheel of the override by the oscillator can be, a variable limit θ _{Γ is} determined .

Frequency oscillator 12 is supplied, as well as a For- ^D * ^c F i g. 6 and 7 show modified analog

merstufe 14 and a pulse width generator 16. A typical B-class amplifier arrangement -.- n. The oscillator 12 may be manually switchable ^Each of these Aiisführungsiormcn is corresponding to the button to select a desired carrier frequency, modified 45 teachings of the present invention, such. B. with the help of the switch 18, or this switch- In the F i g. 6 becomes an input variable of a

processing can also be carried out automatically, driver stage (not shown) to a transformer, which should not be the subject of the invention. This conducted, which has a secondary winding, the output of which is fed to a modulator 20, the base-Emittcr junctions of each of two of the also a modulation input signal from a 5 ° transistors 56 and 58 are connected. This amplifier 22 receives, which has a switching device transistors are fed by power supplies with ent-24, namely at its input, to an opposite polarity, the Tranaus to select from a plurality of input signals from the sistorSö from a positive power supply and shaping stage 14. The shaping stage 14 of the transistor 58 receives an input from the pulse width generator 16 from a negative power supply and the output variables are fed from the output signal, which can be used to control the duration of each transmitted energy pulse according to alternating current to each of the transistors a common connection at the selected carrier frequency. point60, from where you can then go to the load-As can be seen from the wave diagram. device 62 arrive.

namely at the input terminal and output terminal. 60 In Fig. 7, the power supply consists of one At the end of the modulator 20, the modulated signal is transmitted to the transmitter 64, which is a JSSSSTpS 20 i Tibtäk 26 ikl

g g, he a JSSSSTpS

has winding from the modulator 20 to a driver amplifier 26 and the center point to one

conducts, which in turn drives the power amplifier 28 positive Spanpunesquelic (V Λ «.fniiU ·«, «n, #. KoI-

and this supplies the signal converter 30. The TW- lectors of each of the transistors 66 i! nd 68 snd at the amplifier 26 can send signals with a lower 6 _S to opposite ends of the primary winding.

Provide level and the power amplifier 28 in the closed. Each of the emitters d ™ r iSSfÄ

drive linear area, as this leads to a connection point 70 cc of the scincr-

crstcn two periods of Fi g. 4a is shown, or he is connected to the center connection of the secondary winding

connected to a coupling transformer 72, whose primary winding receives the input drive signal. By the polarities shown it will be appreciated that transistors 66 and 68 are connected and switched to power load 74 feed or drive correspondingly opposite half-periods of the power supply.

In Fig. 8 is a schematic circuit diagram of an amplifier module of the type shown in FIG the arrangement according to FIG. 5 can be used. In this case the amplifier sees one B-class operation in a full bridge arrangement. The input variable from a driver stage (not shown) passes through the primary winding of an input transformer 78. An output transformer 80, whose primary winding is connected in such a way that it receives the outputs from all transistor stages can is arranged to have a resistive load 82 feeds or drives, which can be an electroacoustic transducer. Transistors 84 and 86 are connected to a positive voltage power supply at terminal 88. A port 90 one negative voltage source leads to transistors 92 and 94, with the transistors arranged as shown are. During each half cycle, transistors arranged diagonally always conduct so that they one generate full 360 ° output variable on the primary winding of the output transformer 80 and thus on the load 82.

In this way the amplifier operates as a full wave device, up to the power supply limit and the waveform at load 82 is substantially retained. This amplifier however, it can also be operated in an oversteer range and that appearing at the load 82 Waveform is clipped as in Fig. 5 a is shown. It is an operation in either linear or in the overdrive range, which depends on the size of the driver signal that is sent to the Primary winding of the transformer 78 is applied.

The in F i g. The amplifier shown in FIG. 9 is similar to that of FIG. 8, but has a modified power supply arrangement so that full-wave mode of operation is possible from a single power supply source V ,, _see FIG. An input signal from a driver stage is applied to the primary winding of the transformer 98 and this transformer has a plurality of secondary windings which are connected to the bases of the transistors 100, 102 and 104 and 106. In this circuit arrangement, a biasing Regulierverstärker 108 is provided and whose input is connected to the junction of two equal resistors 110 and 112, which resistors are located between the power supply V ,, _s and ground or earth. The output is routed to ground via a capacitor 114 and to the center tap of the primary winding of an output transformer 116, the secondary winding of which supplies the load 118 with energy. With this arrangement, the voltage level at the center tap is kept at half the supply voltage V _PS .

It may be necessary or desirable to use the amplifier shown in FIG. 9 is shown before destruction to protect that occur in the event of a short circuit at or upstream of the driver stage could. 10 shows a driver amplifier 130 which receives an input signal at a terminal 128 and which is connected to ground via a resistor 132. Across the amplifier 130 is a resistor 134 switched on and in parallel with this resistor is a pair of oppositely polarized Zener diodes 136 and 138 connected in parallel. As

»5 a person skilled in the art will recognize, the Zener diodes are working in such a way that they limit the output of the driver amplifier by effectively removing each Cut off half-wave at the generator breakdown voltage.

Further amplifier arrangements are also possible which are based on the teaching of the present invention are constructed and it should be emphasized that the amplifier arrangements shown represent only exemplary embodiments. While the invention itself can basically be applied to power amplifiers for which a high degree of efficiency is important is placed over a very narrow band range with a fundamental frequency and the invention in Connection to a sonar transmitter device has been described, it can also be used in other areas of application such as B. find radar use. It can also be seen that by controlling the degree of overdrive the amplifier will either in a range corresponding to an essentially constant energy output or output variable or in a range corresponding to a substantially constant output voltage, with larger ones Power fluctuations, can be operated.

For this purpose 2 sheets of drawings

209 683/4!

Claims (1)

Switching operation the switching speed according to the above claims: 1. Power amplifiers for both underwater telephony and echo sounding which the output power is concentrated on a narrow frequency bandwidth, characterized by at least one amplifier stage (10; 28) with a driver and control device (16; 26) for selective operation of the Amplifier stage (10; 28) in the overdrive range for echo sounding or in the linear B operating area for underwater telephony.