SU613335A1 - Squarer - Google Patents

Description

the amplifier whose output is the quad output, and the inputs are connected to the output of the active piecewise linear approximator, the initial displacement input of the quad and the output of the digital-to-analog converter that is connected to the information input of the quad.

FIG. Figure 1 shows the block diagram of the quad; in fig. 2 - diagrams explaining his work.

The quadrator contains an active piecewise linear approximator 1, a summing operational amplifier 2, a digital-to-analog converter 3, information input 4, input 5 of the initial displacement, and output 6.

The active piecewise linear approximator 1 contains a summing operational amplifier 7, linear digital-to-analog converters 8 and inverting units 9.

The inputs of the linear digital-analog converters 8 through inverting blocks 9 are connected to the quad input, and the outputs are connected to the corresponding inputs of summing operational amplifier 7, the output of which is connected to one of the inputs of summing operational amplifier 2. Two other inputs of summing operational amplifier 2 are connected respectively to the input 5 of the initial offset of the quad and to the output of the digital-to-analog converter 3, the input of which is connected to the input of the quad. The quad output is the output of summing opamp 2.

Quad works as follows.

The binary code of the argument x is fed to the input of the digital-to-analog converter 3 and to the inputs of the inverting units 9. At the output of the digital-to-analog converter 3, a linear voltage is formed with a maximum value up to (Fig. 2). The inversion units 9 generate a direct and inverse code X to form, at the outputs, the corresponding linear digital-to-analog converters 8 of the increasing and decreasing portions of the triangular voltages and to control the period of the respective groups of triangular voltages. The first group consists of one triangle with height qi, the second - of two triangles with height (J2,

one third of four triangles with a height of 17 *, i.e., with an increase in the number of groups by one, the number of triangular stresses in the group doubles. The triangular voltages from the outputs of the linear digital-to-analog converters 8 are fed to the inputs of summing operational amplifier 7, the output of which for current values of x is the sum of triangular voltages with the opposite sign coming to the corresponding input of summing operational amplifier 2.

Thus, at the output of summing operational amplifier 2, the line voltage from the output of digital-to-analog converter 3 is summed with the value of sum

of triangular voltages gi, qz, qa,, (jn- At output 6, the voltage varies quadratically as l changes from O to I. The number of groups of triangular voltages can be arbitrary depending on the required number of linear approximation plots. The number of linear sections is twice as large as the number of triangular stresses in the last group. Thus, for the example shown in Fig. 2, the number of linear approximation sections is eight, and the number of triangular stresses in the last group is four.

The analytical relationship between the height of the triangular stresses and the type of quadratic function is expressed as

BUT

q, L + B + C; qk (zzl, 2, ..., “),

22ft

Where

9o is the maximum value of the linear voltage at the output of the digital-to-analog converter 3;

qh is the height of triangular stresses in any group of th

(k, 4, ..., n) A, B n C - coefficients of a reproducible quadratic function

1 (x) Ah + Bx + C.

The value of the initial displacement of the linear voltage (at) depends on the value of the coefficient C. The number of linear sections of the approximation / depends on the number

triangular stresses in the form.

When the form of the realized quadratic function in the quadrator changes, the values of qo, qi, ..., qn and the value of the point of initial displacement of the linear voltage at

. The height of the triangular voltages in groups 9), (72, ---. N) is adjusted by changing the values of the resistors at the input of the summing operational amplifier 7. The quantity q and the initial displacement point are set using the corresponding resistors at the input of the summing operational amplifier 2. Thus, the number tunable circuit parameters for changing the form of the function are equal to the number of groups of triangular stresses plus two linear voltage parameters: slope and initial displacement point.

Claims (1)

Invention Formula A quadrator containing an active piece-line approximator whose input is an information input of a quadrator, characterized in that, in order to improve the technical and operational parameters of a quadrator, it contains a digital-to-analog converter and a summing operational amplifier whose output is a quadrator output, and the inputs are connected to the output of the active piecewise linear approximation