SU1078442A1 - Versions of logarithmic function generator - Google Patents

Description

the control pulses are connected to control inputs of the seventh and eighth keys, respectively, the first, second and third outputs of the control pulse generator are connected respectively to the input of the inverter, to the BTOpbff input of the first switch and to the second input of the second switch, the outputs of the first and second switches are connected respectively to the control inputs of the fourth and sixth keys,

2. A logarithmic converter containing a logarithm block, to the input of which the first terminals of the first, second and third keys are connected, the output of the logari-1 block of the world is connected to the first terminal of the fourth key, the first operational amplifier, the output of which is connected through the fifth key to the input of the first the memory unit, the second memory unit and the second operational amplifier, to the non-inverting input of which the second output of the fourth key is connected, the sixth key, the element with controlled resistance, the scaling unit, the input of which o is connected to the second output of the second key, the output of the scaling unit is connected to the second output of the first key, a generator of control pulses, the first output of which is connected to the control inputs of the first and fifth keys, the control input of the second key is connected to the second output of the control generator pulses, the third output of which is connected to the control input of the third key, the second output of which is an information input-output of the logarithmic converter, lepBbivi additional information 3bw input of which It is the second output of the second key, characterized in that, in order to increase its accuracy and extend the functionality of the C4ST to provide anti-log arithmic transformation, the seventh, eighth and ninth keys to it are the first, second, and third mass resistors, the control unit, containing inverter, first

and the second switch, the logical zero signal source, the inverter output is connected to the first input of the first switch, the logical zero signal source output is connected to the first input of the second switch, the logarithm unit is inverted, the output of the logarithm unit is connected via the first large-scale resistor to the inverting input of the first operational amplifier , the output of the first memory block through the second large-scale resistor is connected to the inverting input of the first operational amplifier and to the first output element the second output of which is controlled by a resistance; the sixth switch is connected to the output of the first operational amplifier; the output of the second operational amplifier is connected via the seventh switch to the input of a second memory unit, the output of which is connected to the control input of an element with controlled resistance; the inverting input of the second operational amplifier is the second additional information input of the logarithmic converter, whose information input-input is the first output of the eighth key, the second output The second and third outputs of the control pulses are connected to the control inputs of the seventh and eighth keys, respectively, the inverting input of the first operational amplifier is connected through the third scale resistor and the ninth key to the zero bus potential, the first output of the generator of control pulses is connected to the control input of the ninth key, the first, second and third outputs of the generator of control pulses with dineny respectively to the input of the inverter, a second input of the first switch and to a second input of the second switch, the outputs of the second and first switches respectively connected to the control inputs of the fourth and sixth keys.

The invention relates to devices for converting electrical signals according to the logarithm and can be used in analogue machines.

One of the known logarithmic converters contains a log erifmator, key elements, memory blocks, operational amplifiers, a generator of control pulses 1j.

5 The known device is characterized by low accuracy.

Closest to the proposed is a logarithmic converter containing a logarithm block, to the input of which the first terminals of the first, second and third keys are connected, the output of the first key is the first input of the device and through the scaling unit is connected to the second output of the second key, the second output of the third key is the second input of the device, the output of the logarithmic unit through the fourth key is connected to the first input of the first differential amplifier, the second input of which is connected to the output of the first block Memory, whose input through the fifth switch is connected to the output of the logarithm, the output of the first differential amplifier is connected to the input of an element with a controlled resistance, the output of which is the output of the device and connected to the first input of the second differential amplifier, the output of which is connected through the sixth series the key and the second memory block are connected to the control input of the element with a controlled resistance; the secondary input of the reference source is connected to the second input of the second differential amplifier voltage, the first output of the control pulse generator is connected to the control inputs of the first and fifth keys, the control inputs of the second and sixth keys are connected to the second output of the control pulse generator, the third output of which is connected to the control inputs of the third and fourth keys 2 .

The drawbacks of the device are low accuracy due to the large number of series-connected elements along the input signal conversion circuit and the impossibility of converting the signals back.

The purpose of the invention is to improve the accuracy and enhance the functionality by providing anti-log transformation.

The goal is achieved by the fact that in a logarithmic converter containing a logarithm block, to the input of which are connected the first terminals of the first, second and third keys, the output of the logarithm block is connected to the first terminal of the fourth key, the first operational amplifier, the output of which is connected to the first key through the fifth key the memory unit, the second memory unit and the second operational amplifier, to the non-inverting input of which the second output of the fourth {fifth key, the sixth key, the element with the controlled resistance is connected The scaling unit, the input of which is connected to the second output of the Second key, the output of the scaling unit, is connected to the second output of the first key, a generator of control pulses, the first output of which is connected to the control inputs of the first and fifth key; the control input of the second key is connected To the second output of the control pulse generator, the third output of which is connected to the control input of the third key, the second output of which is the information input-output of the logarithmic converter, first add The second information key contains the seventh and eighth keys, the first and second scale resistors, the control unit containing the inverter, the first and second switches, the logical zero signal source, the inverter output is connected to the first input of the first switch, the signal source output logical zero is connected to the first input of the second switch, the logarithm block is reversed 1 JM, the output of the logarithm block through the first scale resistor is connected to the inverting input the first operational amplifier, the output of the first memory unit through the second large-scale resistor is connected to the inverting input of the first operational amplifier and to the first output of the element with controlled resistance, the second output of which is connected to the output of the first operational amplifier via the sixth key, the output of the second operational amplifier through the seventh the key is connected to the input of the second memory unit, the output of which is connected to the control input of the element with a controlled resistance, the inverting input of the second operating the amplifier is the second additional information input of a logarithmic converter, whose information output-input is the first output of the eighth key, the second output of which is connected to the second output of the element with controlled resistance, the second and third outputs of the control pulse generator are connected to the control inputs of the seventh respectively and the eighth keys, the first, second and third outputs of the generator of control pulses are connected respectively to the input of the inverter, with the second input of the first crossover yuchateli and vtorm input of the second switch, vyho / s first and second switches respectively connected to the control inputs of the fourth and sixth keys. According to the second variant, the well-known logarithmic converter containing the logarithm block, to the input of which the first terminals of the first, second and third keys are connected, the output of the logarithm block is connected to the first output of the fourth key, the first operational amplifier, the output of which is connected via the fifth key to the input of the first memory block, the second memory block and the second operational amplifier, to the non-inverting input of which the second output of the fourth key is connected, the sixth key, the element with a controlled resistance, the scale The scheduling unit, whose input is connected to the second output of the second key, the output of the scaling unit is connected to the second output of the first key, the generator of control pulses, the first output of which is connected to the control inputs of the first and fifth keys, the control input of the second key is connected to the second output of the Control Pulse Generator, the third output of which is connected to the control input of the third key, the second output of which is the information input-output of the logarithmic converter. The first additional information input of which is the second output of the second key, introduced the seventh, eighth and ninth keys, the first, second and third scale resistors, the control unit containing the inverter, the first and second switches, the source of the logical zero signal, the output the inverter is connected to the first input of the first switch, the output of the logical zero signal source is connected to the first input of the second switch, the logarithm block is made reversible, the output of the logarithm block through the first large-scale cut with -air connected to the inverting input of the first operational amplifier, the output of the first memory block is connected via the second large-scale resistor to the inverting input of the first operational amplifier and to the first output of the element with controlled resistance, the second ZYYOD of which is connected via the sixth switch to the output of the first operational amplifier, the output of the second operational 5 rilitator is connected via the seventh key to the input of the second mapping unit, the output of which is connected to the control input of the element with a controllable resistance, inverter The second input of the second aperating amplifier is the second additional information & n input of the logarithmic converter, information: output-input, which is the first terminal of the eighth key, the second terminal of which is connected to the second terminal of the element with a controlled resistance, and the second and third outputs of the generator pulses are connected to the control inputs of the seventh and eighth keys, respectively, the inverting input of the first operational amplifier through the third connected The resistor and the ninth switch are connected to the zero potential bus, the first output of the control pulse generator is connected to the control input of the ninth key, the first, second and third outputs of the control pulse generator are connected respectively to the input of the inverter, to the second input of the first switch and the second input of the second switch, the outputs of the second and first switches are connected respectively to the control inputs of the fourth and sixth keys. FIG. 1 shows a functional diagram of the first variant of the logarithmic converter; Fig, 2 is a functional diagram of the second variant of the logarithmic converter; in fig. 3 is a table of states of keys of a logarithmic converter. The logarithmic converter (Fig. 1) contains the first, second, third, fourth, fifth, sixth, seventh and eighth keys 1-8, block 9 logarithms, the first 10 and second 11 operational amplifiers, the first 12 and second 13 memory blocks , scaling unit 14, first 15 and second 16 scale resistors, element with controlled resistance 17, control block 18, control pulse generator 19, information input / output 20, information output / output 21, first 22 and second 23 information inputs, first 24 and second 25 switches, inver torus 26, the source 27 of the signal logical zero. The logarithmic converter (Fig. 2) contains the first, second, third, fourth, fifth, sixth, seventh and eighth keys 1-8, block 9 logarithms, the first 10 and second 11 operational amplifiers, the first 12 and second and memory blocks , scaling unit 14, first 15 and second 16 scale resistors, element with controlled resistance 17, control block 18, control pulse generator 19, information input / output 20, information output / input 21, first 22 and second 23 additional information inputs , the first 25 and second 25 switches, inverter 26, a logic zero signal source 27, a ninth switch 28, a third large resistor 29, a zero potential bus 30.

The principle of operation of the logarithmic converter (Fig. 1) is as follows.

The control pulse generator generator jCOB generates control signals alternately at the first, second and third outputs. The position of the moving contacts of the first 24 and second 25 switches correspond to the logarithm mode and provides the open state of the fourth key 4 during all the cycles a, B, & (Fig. 3) and the closed state of the sixth key b in the second and third cycles S and b. in the position of the moving contacts of the first 24 and second 25 switches, opposite to the one shown, the anti-logarithm mode is provided, the fourth key 4 is closed in the third cycle b, and the closed key is in the second cycle S (FIG. 3

In the logarithmic transformation, the first and fifth keys 1 and 5 are closed in the first clock of the generator 19 of control pulses. A similar signal is fed to the first additional information input 22, scaled in the scaling block 14 and through the ground first key 1 goes to the input of the logarithmic block 9 .

The result of the logarithmization of the signal through the first large-scale resistor 15 is fed to the input of the first operational amplifier 10, the feedback circuit of which in the first cycle forms a closed fifth key 5,

b (, eo.u ,,. (,,, eu, .Nu, .o, where R | is the resistance of the element with controlled resistance 17; and gj (is the signal on the second additional information input de 23. After the adjustment of the value the resistance of the element with controlled resistance 17 is the transfer coefficient from the first scale resistor 15 to the output of the second operational amplifier 11, JJg.: 3 .. Klopql / C This value of the transfer coefficient is fixed in the second block 1

the first memory block 12 and the second scale resistor 16. In the first memory block 12, a signal is fixed to the end of the first clock cycle

lL6

Kloga ex,

(I) R (

where R, and R |, are the resistances of the first and second large-scale resistors 15 and 16;

c is the coefficient of undercut of the scale unit 14; Ug - signal 1ga of the first additional information input 22; K, N is multiplicative and

additive error of the logarithm block 9.

In the second cycle S of operation of the generator 19 of control pulses, the second, sixth and seventh keys 2, b and 7 are closed. The input signal through the second key 2 is fed to the input of the logarithm, the signal from which through the first scaling resistor 15 is fed to the input of the first operational amplifier 10 In this case, the feedback circuit is formed by a closed sixth key b and an element with controlled resistance 17. During the second cycle, the automatic gain control circuit of the first operational amplifier 10 operates, which-negative feedback resistor form a first scale 15 and the element with controllable resistance 17. The operation condition of the circuit is equal to zero algebraic sum of the input signals of the second operational amplifier 11

(2) the memory and stored for the third b and the first a cycle. During the third cycle i of operation of the generator 19 of control pulses, the third, sixth and eighth keys 3, 6 and 8 are closed, and the first 12 and second 13 memory blocks are in the storage mode. The signal from information input / output 20 through the third key 3 is fed to block 9 logarithmization. The first operational amplifier 10 provides precise summation with the output signal of the first memory block 12. The resulting signal at information output 21 is 1G - 2fiUJ I1 7T, logVl / C ° K

where Ugjj is the input-output signal 20.

In the antilog mode, the first two clock cycles are similar to those described. In the third cycle, the fourth key 4 is closed and the sixth key 6 is opened. The input signal via the eighth closed key 8 is sent to the information output-input 21 and added to the output signal of the first unit 12 at the input of the first operational amplifier 10 memory and logarithm block 9 post: the signal drops

:five)

KloggCUBX22 + N

After the anti-logarithm in the reverse logarization unit 9, the information signal is formed at the information input 21

ir Eurfa C U si a ()

From the expressions (O and (6) it follows that the result of both rym and

V

The inverse transformation does not depend on the additive and multiplicative components of the error of block 9 logarithms. The error due to the operation of the second operational amplifier 11 is reduced in the second variant of the logarithmic converter,

In the first cycle of operation, the ninth key 28 is closed, when the signal is recorded in the first memory block 12. In the third case, the first opamp 10 of the same magnitude is also subtracted from the bias voltage;

stored in the first memory block 12,

Thus, in comparison with the prototype device, the proposed variants of a logarithmic converter are characterized by higher accuracy of operation and the possibility of anti-log conversion of input signals.

phage.

Claims (3)

LOGARITHMIC CONVERTER (ITS OPTIONS) 1. Logarithmic converter containing a logarithmic unit, to the input of which the first conclusions of the first, second and third keys are connected, the output of the logarithmic unit is connected to the first output of the fourth key, the first operational amplifier, the output of which through the fifth key is connected to the input of the first memory block, the second block memory and a second operational amplifier, to the non-inverting input of which the second output of the fourth key is connected, the sixth key, an element with controlled resistance, a scaling unit, whose input is is dined with the second output of the second key, the output of the scaling unit is connected to the second output of the first key, the control pulse generator, the first output of which is connected to the control inputs of the first and fifth ... keys, the control input of the second key is connected to the second output of the control pulse generator, the third output of which connected to the control input of the third key, the second output of which is the information input-output of the logarithmic converter, the first additional information input of which is the second output of the second key, characterized in that, in order to increase its accuracy and expand functionality by providing anti-logarithmic conversion, the seventh eighth keys, the first and second large-scale resistors, a control unit containing an inverter, the first and second switches are introduced into it , a logical zero signal source, the inverter output is connected to the first input of the first switch, a logical zero signal source output is connected to the first input of the second switch, the block is logarithm It is made reversible, the output of the logarithm unit through the first scale resistor is connected to the inverting input of the first operational amplifier, the output of the first memory unit through the second scale resistor is connected to the inverting input of the first operational amplifier and to the first output of the element with controlled resistance., the second output of which is through the sixth key connected to the output of the first operational amplifier, the output of the second operational amplifier through the seventh key is connected to the input of the second memory block, the output of which о is connected to the control input of the element with controlled resistance, the inverting input of the second operational amplifier is the second additional information input of the logarithmic converter, the information output of which is the first output of the eighth key, the second output of which is connected to the second output of the element with controlled resistance, the second and third outputs 1078442 control pulse generators are connected to the control inputs of the seventh and eighth keys, respectively, the first, second and third the outputs of the control pulse generator are connected respectively to the inverter input, to the second input of the first switch and to the second input of the second switch, the outputs of the first and second switches are connected respectively to the control inputs of the fourth and sixth keys .. 2. A logarithmic converter containing a logarithmic unit, to the input of which the first conclusions of the first, second and third keys are connected, the output of the logarithmic unit is connected to the first output of the fourth key, the first operational amplifier, the output of which through the fifth key is connected to the input of the first memory block, the second block memory and a second operational amplifier, to the non-inverting input of which the second output of the fourth key is connected, the sixth key, an element with controlled resistance, a scaling unit, whose input is dinene with the second output of the second key, the output of the scaling unit is connected to the second output of the first key, the control pulse generator, the first output of which is connected to; the inputs of the first and fifth keys, the control input of the second key is connected to the second output of the control pulse generator, the third output of which is connected to the control input of the third key, the second output of which is the information input-output of the logarithmic converter, the first additional information input of which is the second output of the second key, characterized in that, in order to increase its accuracy and expand functionality by providing antilog.arithmic conversion, not about introduced the seventh, eighth and ninth keys, the first, second and third scale resistors, a control unit containing an inverter, first and second switches, a logic zero signal source, the inverter output is connected to the first input of the first switch, the output of the logical zero signal source is connected to the first the input of the second switch, the logarithm unit is reversed, the output of the logarithm unit through the first scale resistor is connected to the inverting input of the first operational amplifier, the output of the first unit through a second scale resistor is connected to the inverting input of the first operational amplifier and to the first output of the element with controlled resistance, the second output of which through the sixth key is connected to the output of the first operational amplifier, the output of the second operational amplifier through the seventh key is connected to the input of the second memory block, the output of which connected to the control input of the element with controlled resistance, the inverting input of the second operational amplifier is the second additional information input ohm of a logarithmic converter, the information input-output of which is the first output of the eighth key, the second output of which is connected to the second output of the element with controlled resistance, the second and third outputs of the control pulse generator are connected to the control inputs of the seventh and eighth keys, respectively, inverting the input of the first operational amplifier through a series-connected third scale resistor and a ninth key is connected to the zero potential bus, the first output of the control generator pulses are connected to the control input of the ninth key, the first, second and third outputs of the control pulse generator are connected respectively to the inverter input, to the second input of the first switch and to the second input of the second switch, the outputs of the second and first switches are connected respectively to the control inputs of the fourth and sixth keys. torus, key elements, memory blocks, operational amplifiers, control pulse generator [1]. 5 A known device is characterized by low accuracy.