SU809238A1 - Function generator - Google Patents

Description

The invention relates to analog and analog-digital computing technology. Known function generator containing a software unit that sets the potentiometers, keys and integrator. The piecewise linear output signal of this generator is obtained by integrating rectangular pulses arriving through successively open keys with given potentiometers II. Its disadvantage is the effect of accumulation of error with an increase in the sequence number of the generated part of the function. The closest technical solution is a functional generator that contains an integrator, the output of which is the generator output, a multi-phase multivibrator, an analog storage device connected by the output through the first summing resistor to the integrator input, and the input through the bit key, the control input of which is generator synchronization input - to the integrator output, the second summing resistor connected to the integrator input, n setting potentiometers, each of which is fixed contacts to the buses of positive and negative support voltage, n keys, the information input of each of which is connected to the movable contact of the corresponding setpoint potentiometer, the control input - with the corresponding output of the multiphase multivibrator, and the output with the free output of the second summing resistor, the input of the multifibres multivibrator connected entry key bit 2. The disadvantage of such a generator is the reduced accuracy of the reproduction of the function of time due to the drift of the integrator at each section of the partition. The purpose of the invention is to improve the accuracy of the reproduction of the function of time. This is achieved by the fact that a function generator containing an integrator, the output of which is the generator voltage, a multi-phase multivibrator, an analog storage device connected via the first summing resistor to the integrator input, and an output through a dongle whose control input

is the synchronization input of the generator to the integrator's input, the second summing resistor connected to the integrator input, n setting potentiometers, each of which is connected by fixed contact to the buses of the positive and negative reference voltage, n keys, each information input of which is connected to the moving contact the corresponding setpoint potentiometer and the control input with the corresponding input of the multi-phase multivibrator, additionally contains the counter first and second digital-analogue outputs The creators, the third summing resistor, n additional keys (n + 1) -th setting potentiometer, connected non-movable and contacts to buses of positive and negative reference voltages, and a moving contact to the information input of the n-th additional key, control inputs of additional keys are connected with the corresponding control inputs of the keys, the information input of each of the additional keys, except for the n-th one, is connected to the information input of the next key according to the key number; the key outputs are connected to the analog input the first digital-to-analog converter, the digital inputs of which are connected to the direct outputs of the counter bits, and the output with the free output of the second summing of its resistor, the outputs of the additional keys are connected to the analog input of the second digital-analog converter, the digital inputs of which are connected to the inverted outputs of the counter , and the output through the third summing resisor, the torus - with the integrator input; the output of the higher bit of the counter is connected with the input of the multi-phase multivibrator; the counting input of the counter yuschim input bit dnogoklyuch

FIG. 1 shows the functional generator, circuit; FIG. 2 shows timelines for the formation of two parts of the time function;

The functional generator contains an integrator 1, an analog storage device 2, a first summing resistor 3, a discharge switch 4, a second summing resistor 5, a third summing resistor 6, n + 1 specifying

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potentiometers 7

p /

whose 8, ... 8, and h additional keys 9, .., .. 9 ,, the first and second multiplying digital-to-analog converters 10,11, multi-phase multivibrator 12, counter 13.

Functional generator operates as follows.

The synchronizing pulses from the synchronous input D | of the generator are fed to the input of the counter 13 and to the control input of the dongle 4. Signals from the direct and inverse outputs

the counter 13 is supplied to the digital inputs of the first and second digital to analog converters 10 and 11, respectively, the output voltages of which through the second and third summing resistors 5 and 6 are fed to the integrator input. In case of overflow: counter 13, the pulse from the output of the most significant bit is fed to the input of the multi-phase multivibrator 12, changing its state. At each overflow, the outputs of the multi-phase multivibrator 12 from 1 to 5 are sequentially excited, the signals from which sequentially open the main 8,.,. 8 keys and additional 9,. ., 9 „keys. As a result, the analog inputs of the first and second digital-to-analog converters 10 and 11 receive square-wave pulses, the amplitude values of which are controlled by potentiometer 7, 7. correspond to the nodal ordinates of the time function, nor,

On the recalculation by the counter of 13 clock pulses, the transmission coefficients of the digital-to-analog converters 10 and 11 vary according to a linear-step law: for the first - for the descending (Fig. 2a), for the second (Fig. 26) for the ascending. By summing the output currents of the D / A converters 10, 11 flowing through the second and third summing resistors 5, 6 to the input of the integrator 1, a piecewise-step approximation of the linear portions of the time function occurs. .

If there is feedback from the integrator 1 .. through the bit switch 4, the analog storage device 2 and the first summing resistor 3, the response of the integrator 1 to the single increment of the counter 13 has the form of a triangle. Each interval of the piecewise linear approximation is formed by summing the triangles (FIG. 2d), due to which there is no error accumulation effect in the proposed generator.

In order for the approximation nodes not to have flat vertices during one cycle, the counter 13, which was set to 0 in the initial state after 0 Overflow, should not be reset.

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O, a have lower de I 11 11 j- t

The advantages of the invention compared to the prototype consist in a finer partitioning of the function with the same number of approximation nodes as the prototype, whereby the integrator integrates the input voltage continuously several times shorter. This makes it possible to reduce the error caused by the drift of the integrator several times, as a result of which the accuracy of the time function is reproduced.

Claims (2)

Invention Formula A function generator containing an integrator whose output is a generator output, multi-phase, a multivibrator, an analog storage device connected by an output through a first summing resistor to the integrator input, and an input through a bit switch, the control input of which is a generator synchronization input - to the integrator output, the second summing resistor connected to the integrator input, n setting potentiometers, each of which is connected with fixed contacts to the positive and negative buses a reference voltage, p keys, the information input of each of which is connected to the moving contact of the corresponding setpoint potentiometer; and the control input is connected to the corresponding input of the multiphase multivibrator, characterized in that it contains a counter, first and second digital-analogue converters , the third summing resistor, n additional switches, (n) -th setting potentiometer, connected by fixed contacts to the buses of positive and negative reference voltages, and By the contact to the information input of the nth additional key, the control inputs of the additional keys are connected to the corresponding –control inputs of the keys, the information input of each of the additional keys, except for the nth key, is connected to the information input of the next key number, the outputs of the keys are connected with the analog input of the first D / A converter, whose digital inputs are connected to the Direct Outputs of the counter, and the output to the free output of the second summing resistor, the outputs of the additional keys it is connected to the analog input of the second digital-to-analog converter, the digital ones connected to the inverse outputs of the counter, and the output via the third summing resistor to the integrator input, the high-discharge output of the counter connected to the input of the multiphase multivibrator, the counting input of the counter connected to the control input of the discharge one key. Sources of information taken into account in the examination 1, Anisimov B.V., Golubkin V.N. 5 Analog Computers M., Higher School, 1972, p. 433, fig. IX.19. 2. Authors certificate of the USSR 398963, cl. G About G 7/26, 1972 0 (prototype). op -AW f o H Y hh -about gigit ,, J puek  i V V Y X to K L / V v v v