SU1034050A1 - Frequency pulse device for extracting square root - Google Patents

Abstract

FREQUENCY-IMPUDSNOK DEVICE FOR EXTRACTION OF SQUARE ROOT / comprising threshold element whose output, vlshoschyys output device connected to the input of the pulse shaper, series-connected source of the converted signal, the first and second integrators, each of which comprises an operational amplifier, a feedback which communication circuit a capacitor and a switch are connected in parallel, the output of the operational amplifier is the output of the integrator, and the input of the operational amplifier is connected via a large-scale resistor to one integrator, the output of the pulse driver is connected to the control inputs of the keys of the first and second integrators, which is distinguished by the fact that, in order to increase its accuracy, two voltage dividers and an algebraic adder are entered, the first summing input of the algebraic adder is connected to the output the second integrator, and vy the course of the algebraic adder is connected (L chen to the input of the threshold element, the inputs of the first and second integrators through the first and second divisors of the voltage (the generators are connected respectively to to the second summing and subtracting, S inputs is an algebraic adder.

Description

00 4 О СП The invention relates to measuring and computing techniques and can be used in schemes for measuring the effective value of a signal and for linearizing the characteristics of sensors. Analog devices for square-root extraction are known, containing an operational amplifier and a quadrant l, included in its feedback circuit. The disadvantage of such devices is low accuracy, due to the error in performing the squaring operation, and low dynamic range. The closest to the present invention is a pulse-frequency device for extracting the square root, containing a threshold element and connected to its output a pulse shaper, as well as serially connected source of the converted signal, first and second integrators at the operational amplifier with an input resistor and a parallel-connected capacitor and a bit switch in the feedback circuit, the output of the pulse driver connected to the control inputs of the bit switches 112 3. The disadvantage of the known device is a low accuracy of the operation of extracting the root, which is connected with the error determined by the discharge time of the integrator capacitors. The purpose of the invention is to increase the precision of the operation of extracting the ad horn. one . This goal is achieved by the fact that in a frequency-pulse device for extracting square root, containing a threshold element, the output of which is the output of the device connected to the input of the pulse former, serially connected source of the converted signal, the first and second integrators each of which contains an operational an amplifier, in a feedback circuit of which a capacitor and a switch are connected in parallel, the output of the operational amplifier is the output of the integrator and the input of the operational amplifier is black A corresponding scale resistor is connected to the integrator input, the Output of the pulse driver is connected to the control inputs of the keys of the first and second integrators, two voltage dividers and an algebraic adder are added, the first summing input of the algebraic adder is connected to the output of the first integrator, and the output of the algebraic adder is connected to the input of the threshold element, the inputs of the first and second integrators through the first and second voltage dividers are connected respectively to the second summer present and subtracting input of an algebraic adder. The drawing shows a diagram of the proposed device. The pulse frequency device for square-root extraction contains a source 1 of the signal to be converted, integrators 2 and 3, algebra and black adder 4 threshold element: 5, shaper of impulses, keys 7 and 8, dividers 9 and 10, on the other hand, operational amplifiers 11 . and 12, an adder, capacitors 13 and 14, and scale resistors 15 and 16. A pulse frequency device for extracting a square-root operates as follows. When the voltage signal at the output of the source .1 is transformed, the output signals and the output signals of the first 2 and second 3 integrators change in accordance with the equations: and - Ks and q; about . V - glm lS KiЦ: at-i4kgK, 01t, p about dKyo k / j and ka are the transmission coefficients of the first and second integrators, respectively. The output voltage of the algebraic adder 4 is V-i44J. . where k and k are the transmission coefficients of the first 9 and second 10 voltage dividers, respectively. When the output voltage of the comparison element 4 reaches the switching voltage of the threshold element 5, the latter switches. The result is the launch of the imager b. reset pulses, the closure of the first 7 and second. 8 keys, bypassing the capacitors 13 and 14 of the integrators, the return of the latter to the original source. The process is then repeated periodically. The moment of switching the threshold element 5 is determined from the ratio 4 i.H, 4. de t is the time from the beginning of the process and from the moment of switching to the moment of switching the threshold element. It is found by solving the last quadratic equation t - - J + / ni2ir5or ×, and Kj- K |

Since t-, O, then with QC - P

  TO%

The period of the output pulses is equal to the sum of the integration time t ,. and time tp

 rivv-lfWf - ,,. ip

The frequency of the output pulses is equal to

R

"FS:

If you choose

V-44;% - r

l

WMiik

that

  about

those. the frequency of the output pulses is strictly proportional to the square root of the input signal.

The technical and economic effect of the invention is to increase the device’s precision.

Claims (1)

FREQUENCY-PULSE DEVICE FOR EXTRACTING A SQUARE ROOT; containing a threshold element, the output of which, which is the output of the device, is connected to the input of the pulse shaper, the source of the converted signal *, the first and second integrators, each of which contains an operational amplifier, in the feedback circuit of which a capacitor and a key are connected in parallel, the output of the operating the amplifier is the output of the integrator, and the input of the operational amplifier through a large-scale resistor is connected to the input of the integrator, and the output of the pulse shaper is connected to the control the key inputs of the first and second integrators, which is related to the fact that, in order to increase its accuracy, two voltage dividers and an algebraic adder are introduced into it, and the first summing input of the algebraic adder is connected to the output of the second integrator, and the output of the algebraic adder is connected to the input of the threshold element, the inputs of the first and second integrators through the first and second voltage dividers are connected respectively to the second summing and subtracting inputs of the algebraic adder. az) _§_and ap. 10340 50