SU443393A1 - Device for reproducing the functions of two variables - Google Patents

Description

The invention relates to analog computing and MOJKET to find application on analog computing machines when playing back functions of two variables. It is known device auth st. - 267196 for reproducing functions of two variables, containing linear elements, summing amplifier and diode function converters with variable reference voltages. A disadvantage of the prior art arrangement is the low accuracy of the product of a given family of functions due to the use of the piecewise linear approximation principle. In order to increase the accuracy of operation, the proposed device of a similar purpose contains two quadrs, the inputs of which are connected respectively to the first and second variables, and an additional resistor in each diode element of the functional converters, one of which is connected to the connection point of the main and the compensation the second terminal of the resistor of the diode elements of the even-numbered functional devices, is connected to the output of the first quad, and rubbing the clip of the resistor of the diode elements of the odd-functional converters to the output of the second quad. FIG. L is a block diagram of the device; on FiGe2a, an example of a piecewise quadratic approximation of a family of functions of two variables X, Y; in fig. 26 - family of errors and on-approximation of this family. Functional converters 1–3 (see Fig. 1) contain diode cells, which include diodes 4i – 4p with resistors 5-g – 5l, 6i-6rt, 7i- (fi and compensating diodes 8-g- 8p. Diode outputs: Chcdly connected to the input of one rational amplifier .9, The inputs of the diode elements are connected to the outputs of the line elements 10 by the reference voltage. functional converters 1-3 are connected to the input of operations ion amplifier I3j, the voltage at the output of which corresponds to the reproduced function.

To reproduce the family of curves f CX, Y; produce a piecewise quadratic approximation of the curves bounding the domain of definition of a given function by one of the variables (for example, by Y), or two other curves selected in the working area of variation of the variables. For approximation, the method of graphical approximation of the first derivative of a given family of linearly broken lines is used, or the parameters of parabolic segments are calculated:

) at- fiiX- Ci, X on a digital computer.

In this case, it is necessary that all approximating portions of one curve or a part of them be described by those /; all equations, as the corresponding approximating portions of another curve. .

For each three-input diode element, which produces parabolic segments, set; linear voltage-voltage unlocking diodes L1 - 4Ul, from the second variable Y. These dependences are straight lines by the equation

Chap 01 through to tU, passing through the opening points of the diode for the two approximated curves.

In the same way, the linear dependence on the variable Y is given by the quantity of the function J (X, Y).

After that, the values of the coefficients C (| ,, b |. And

C1 for each diode element with a set of resistance values for the input of the 11XX diode element resistors.

As a reference voltage, the output of the linear element iD is used, reproducing the dependence VONI-JonDL-f-iy-.

1 obtained in such a way .iui3TBO curves f (l, Y), reproduced by UHJoa functional transform of type I, is shown in (T) ig.2a of curve f, and are reproduced by CHJ ii Я1 -

 ex., Do) HoiiT given by CCIAUMCTBO

with a certain error, which is represented in the form of a curve J, CX, Y) SPHIG.26).

 The family of curves ("Y") is reproduced in the same way, for which use the functional transducer 2,

The output at the output of the operational amplifier 13 is the sum of the voltages corresponding to: fi (X.Y., +, y), shown in FIG. 2a of the curve, reproduces the given function f (X.Y.) with some error 3) which is reproduced by the functional converter 3. n

Curve 2.1 (X, Y) in FIG. 2a corresponds to the representation of a given family- (X.Y.) by the sum of three functions: f (X, Y). fi (X, Y) l.T

+ 3,

Practically for brass

function of the two variables with dostatochnoy. accuracy can be limited by the representation of a given function as the sum of three functions of the type considered.

The use of the piecewise quadratic approximation principle makes it possible to significantly reduce the number of diode elements of each of the indicated functional converters 1-3 and to improve the reproduction accuracy of a given family of

.1ET INVENTIONS

Device for playing back the functions of two variables according to the author SAT. 2671%, characterized in that, in order to improve the accuracy of work, it contains two quadrs, the inputs of which are connected respectively to voltage sources proportional to the first and second variables, and an additional resistor in each diode element of the functional converters, one clip of which is connected to a point connection of the main and compensating diodes, the second terminal of the resistor of the diode elements of even, functional converters is connected to the output of the first quad, and the terminal of the resistor of the diode ENTOV functional odd inverters to the output of the second squarer and Figs 2a fiM X,

v;

/five

 V: f, () (, M) (. Y)

FIG. 26