SU1322161A2 - Device for determining extrema of electric signal - Google Patents

Abstract

The invention relates to measuring and computing technology and can be used in measuring information systems for analyzing random electrical signals. The purpose of the invention is to expand the field of application by providing work with an alternating signal of arbitrary shape. The device contains an analog-to-digital converter, a storage register, a register of extreme values, two. Elements TOGETHER OR, an arithmetic unit, a selector, a display unit, an OR element. Extremes are recorded when the sign of the difference between two adjacent samples of the input signal is changed. Extreme value is remembered. The introduction of two elements EXCLUSIVE OR ensures the correct fixation of the signs of the increment values when the signal passes through a zero level. 1 il. o (l

Description

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The invention relates to measuring and computing technology, can be used in measuring and information systems for analyzing random electrical signals 5 and is an improvement of the device according to the author. St. No. 1273816.

The purpose of the invention is to expand the scope of application by providing work with an alternating signal 10 of arbitrary shape.

The drawing shows a diagram of the proposed device.

The device contains an analog-to-digital converter (ADC) 1, which stores the register 2, the register 3 of extreme values, the first 4 and the second 5 elements EXCLUSIVE RSHI, the arithmetic unit 6, the selector 7, the display unit 8 and the element OR 9. The selector 7 20 contains elements 10 and 11, D-flip-flop 12, pulse shaper 13 and element OR 14. Block 8 contains a D-flip-flop 15 and pulse shapers 16 and 17.

The device works as follows.

The electrical signal under study is fed to the analog input of the A / D converter 1 and is converted into a digital code at the times specified by control pulses (at the Start input). Simultaneously with the appearance at the information output of A / D converter 1 of the input signal at its clock output 35 The short pulse is the End of Measurement (CI).

The first QI pulse is passed by the shaper 13 (the next ones are blocked by it) at the output and through the element OR 14 it acts on the control input of the storage register 2, as a result of which the value of the output code of the ADC 1 is entered into this register.

This refers to the first conversion cycle 45 of the A / D converter 1.

In the subsequent conversion cycles, the input of information to the storage register 2 and the register 3 of extreme values is performed as follows.

The arithmetic unit 6 operates as a subtractor at those moments of the belt where there is no zero-to-zero transition accompanied by a change in the polarity of the input signal. At the time of the zero crossing in order to determine the quantization step of the input

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signal, and accordingly, the resolution in the determination of extrema, the arithmetic unit 6 with the help of the element EXCLUSIVE R1 and 4 goes into the summation mode of the input signals.

By the cut of the CI pulses, the selector 7 analyzes the code set at the information output of the arithmetic unit 6. Pre-arithmetic unit 6 subtracts or adds (when going through zero) the code coming from the ADC outputs 1 with the code set on the information outputs of the storage register 2. As a result, in the subtraction mode, the difference modulus is set at the information output of the arithmetic unit 6, and in the addition mode (at zero crossing), the sum odules predschuschego the stored value and the current value of the electric signal. The code is analyzed by the selector 7, which is the control node implementing the adaptive sampling of the coded values of the input signal. The impulse at the outputs of D-flip-flop 12 and the element OR 14 is cut only when the simplification code at the output of the arithmetic unit 6 exceeds a predetermined threshold value that exceeds the interference level. The threshold element is the element AND 10, to the inputs of which several lower bits of the block 6 are connected. The pulse from the output of the element OR 14 updates the information in the storage register 2.

The operating mode of the arithmetic unit 6 is set using the EXCLUSIVE SHZh 4 element. If the signal does not change sign, then the output of the EXCLUSIVE IL 4 element is set to a low logic level and the arithmetic unit 6 operates in the subtraction mode. In the case of a zero-crossing signal at the output of the EXCLUSIVE OR 4 element, a high logic level signal is established and the arithmetic unit 6 performs the operation of splicing the current coded value of the signal with the previous one. This ensures that sampling is unchanged near zero.

The formation of the extremum moments is carried out with the help of the second ele. 3132

EXCLUSIVE OR 5 and display unit 8 when changing the sign of the difference between the current and previous coded values of the signal under investigation.

The change in the sign of the difference is monitored by the EXCLUSIVE OR 5 element by two signals: the sign signal from the ADC 1 output and the sign signal from the output of the arithmetic unit 6. Therefore, the device with the additionally entered elements EXCLUSIVE OR 4 and 5 provides registration of extremes, if the signal fluctuates relatively zero.

Impulses max. and Min. at the outputs of the formers 16 and 17 are formed on a slice of the signal KI for one clock at the moments of time determined by the selector 7. These pulses through the element OR 9 are fed to the control input of the register 3 of extreme values, ensuring reception of the extreme coded value of the output signal of the ADC 1 .

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Claims (1)

Image formula A device for determining the extremes of an electrical signal according to the ed. St. No. 1273816, characterized in that, in order to expand the scope of application by providing work with an arbitrary sign of the alternating signal, the first and second elements EXCLUSIVE 1-SHI are entered into it, while the sign output of the analog-digital converter is connected to the first inputs of the elements EXCLUSIVE OR and with the sign input of the memory register, the sign output of which is connected to the second input of the first element EXCLUSIVE OR, the output of which is connected to the control input of the sign of the second term of the arithmetic unit, sign vy output of which is coupled to a second input of the second exclusive OR element whose output is connected to the data input of D-flip-flop indication unit. Compiled by 1. Osipov Editor I.Nikolaychuk Tehred A.Kravchuk Proofreader-I.Muska . J U- - Ш1- жц-. J - - -. --... .-. - Order 2857/39 Circulation 730 Subscription BNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4