SU798609A1 - Voltage digital meter - Google Patents

Description

(54) DIGITAL STRESS METER

one

The invention relates to a pulse technique and can be used in information-measuring systems, automated process control systems, in the creation of analog-digital converters.

A device for measuring the voltage of electronic signals, containing two parallel-connected amplifiers, a series-connected correlator, a subtractor and a recorder, a series-connected additional subtraction unit and a quadrant, the output of which is connected to one of the inputs of the main subtraction unit, and the inputs are correlating, is known. torus and an additional subtraction unit are connected to the outputs of the amplifiers ft.

A disadvantage of the known device is low accuracy due to residual voltage of analog elements.

The closest technical solution to the present invention is a digital follow-type voltage measuring instrument, containing a series-connected pulse-amplitude modulator of the measured voltage, a wideband amplifier, demodulator, low pass filter, comparator, And element, reversible counter and digital-analogue the converter, an additional element And, the input of which is connected. n - with the second output of the comparator, and the output - with the second -. the input of the reversible counter, a clock pulse generator, the output of which is connected to the second control inputs of the amplitude-4cm-pulse mode of the input voltage sensor and demodulator J2.

A disadvantage of this device is also low accuracy.

The purpose of the invention is to improve the measurement accuracy.

The goal is achieved by the fact that in a digital voltage meter containing a pulse amplitude modulator of the measured voltage, after successfully connected reversible cjer chik and digital-analogue converter And serially connected comparator and element And, the source of the reference voltage and clock generator the output of which is connected to the second control input of the amplitude-pulse modulator of the measured voltage are introduced the amplitude-pulse modulator of the reference voltage, the input of which is connected to the source of the reference voltage and the output is from BTopbiM. input of a digital-analog converter, a clock frequency amplifier whose input is connected to the output of an input-voltage modulator of the measured voltage, a high-pass filter whose input is connected to the output of the clock frequency amplifier, and an output to the comparator's input, an additional high-pass filter, input which soy is dinene with the output of a digital-to-analog converter, and the output is with the second input of the comparator, the element NOT, whose input is connected to the output of the element I, JK is the trig ger, the first and second inputs of which are connected to Respectively, with the outputs of the elements AND, NOT and the output of the clock pulse generator, and the direct and inverse outputs with the enabling inputs, respectively, for addition and subtraction of the reversible counter, the phase-shifting circuit, whose input is connected to the clock generator, and the output - with the second input of the element I, the second control input of the amplitude-pulse modulator of the reference voltage, and the third counting input of the reversible counter. The amplitude-pulse modulation of the measured and reference voltages, together with the specified logical processing, ensure the preservation of information about the amplitude values of the measured voltage and improves the accuracy of the digital-analog converter with changes in the characteristics of the electrical elements. FIG. I is a block diagram of a digital voltage meter; Fig. 2 are time diagrams explaining his work. The proposed device contains an amplitude-pulse modulator I of the measured voltage, a generator of 2 clock pulses, an amplifier 3 clock frequencies, a filter 4 of the upper frequencies, a comparator 5, a source 6 of the reference frequency and the amplitude modulated pulse voltage 7 , azo-shift, chain 8, digital-to-analog converter 9, reversible counter 10, additional pin C-high-frequency element I 12, element NOT 13 trigger 14. Measured voltage (fig. 2a; applied to the pulse-amplitude modulator of the measured voltage I and modulates c with a frequency of clock pulses (Fig. 26) coming from a clock pulse generator 2. A clock frequency amplifier 3 isolates and amplifies from the modulated input voltage (Fig. 2c) the first harmonic U) ((Fig. 2d), which comes in the high-pass filter 4 to the comparator 5. The reference voltage from the source 6 of the reference voltage is supplied to the amplitude-pulse modulator 7 of the reference voltage and is modulated by the clock pulses shifted by the phase-shifting circuit 8 and the quarter-cycle (fig.2d). From the output of the D / A converter 9, the modulated reference voltage (Fig. 2e), whose amplitude U corresponds to the code at the output of the reversible counter Yu, is fed through an additional high-pass filter 11 to the second input of the comparator 5. From the output signal (Fig. 2, ) Comparator 5, element 12, produces a gating method using pulses (Fig. 2h) corresponding to a sinusoidal voltage above. The HE element 13 performs their inversion (Fig. 2i). The T K -thrigger 14, in the presence of the indicated pulses (Fig. 2c), which corresponds to the condition Yz, outputs a reversing counter 10 on the trailing edge of the clock pulses (Fig. 2.6). permission for addition (Fig. 2, k), and in their absence, it corresponds to the condition Uic U to the signal of permission for subtraction (Fig.2l). At the same time, the output code of the reversible counter 1O varies along the falling edge of the clock pulses shifted by a quarter of the period (Fig. 2e). The operation of the reversible counter U in the mode of addition and subtraction is conventionally shown, respectively, in FIG. 2m and FIG. 2n. Such an embodiment of the device makes it possible to increase the accuracy of the analog-to-analog conversion in the trace mode with the departure of the characteristics of the elements of the digital voltage meter. Formula of Invention A digital voltage meter containing an amplitude-pulse module of the mountains of the measured voltage, a series-connected reversible counter and a analogue converter, a series-connected comparator and an element. And, a reference voltage source and a reteeparop clock pulses, the output of which connected to the second control input of the amplitude-pulse modulator of the measured voltage, characterized in that, c. In order to improve the accuracy of measurements, an amplitude-pulse modulator of the reference voltage was inputted into it, the input of which is connected to a source of reference voltage, $ output - with a second input of a digital-to-analog converter, an amplifier of the clock frequency, the input of which is connected to the output of an amplitude-pulse modulator measuring voltage, the high-pass filter, whose input is connected to the output of the clock frequency amplifier, and the output to the input of the comparator, an additional high-pass filter, whose input is connected to the digital output alogovogo converter, 25

and the output is with the second input the comparator (H) a, the element NOT, the input of which is connected to the output of the element I, JK is a trigger, the first, second and third inputs of which are connected, respectively, to the outputs of the elements AND, NOT and the output of the clock generator, and direct and inverse outputs with permitting inputs, respectively, for addition and subtraction of a reversible counter, a phase-shifting circuit, the input of which is connected to a clock pulse generator, and an output with a second input element of A, the second control input of amplitude-pulse 5 op modulator polar voltage and a third counting input of the reversible counter.

Sources of information taken into account in the examination

I. USSR Copyright Certificate No. 571759, class G 01 R 19/02, 04/02/74.

2 .. Shl ndin V.M. Digital measuring transducers and devices. M., Higher School, 1973, p. 2p7, 229.

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Claims (1)

Claim A digital voltage meter containing an amplitude-pulse mode 5 798609 measured voltage frog, a reversible counter and a digital-to-analog converter connected in series, a comparator and an I element connected in series, a reference voltage source and a clock generator, the output of which is connected to the second control input of the amplitude-pulse modulator the measured voltage, characterized by heme, which, in order to improve the accuracy of measurements, an amplitude-pulse reference voltage modulator is introduced into it voltage, the input of which is connected to the output of the digital-to-analog converter, the clock amplifier, the input of which is connected to the output of the amplitude-pulse modulator of the measured voltage, a high-pass filter, the input of which is connected to the output of the clock amplifier on the 20th and the output is with the input of the comparator, an additional high-pass filter, the input of which is connected to the output of the digital-analog converter, 25 and the output is with the second input of the comparator, the element is NOT, the input of which is connected is connected with the output of the And element, JK is the trigger, the first, second, and third inputs of which are connected 5, respectively, with the outputs of the And, NOT elements and the output of the clock generator, and the direct and inverse outputs are with enable inputs, respectively, for addition and to subtracting a reversible counter, a phase-shifting circuit, the 'input' of which is connected to a clock pulse generator, and the output with a second input of an And element, a second control input of an amplitude-pulse <5th voltage modulator and a third counting input of a reverse counter.