SU1597756A2 - Digital voltmeter - Google Patents

Abstract

The invention relates to electrical measuring equipment and can be used in process control and monitoring systems. The purpose of the invention is to extend the functionality by determining the mean and mean square values of a signal both for its period and for a given time interval - is achieved by the fact that the voltmeter containing input amplifier 1, analog-to-digital converter 2, period determining unit 3, driver 4 frequencies, control unit 5, pulse generator 6, multiplier 7, sample volume counter 8, accumulator adder 9, output register 10, synchronization unit 11 is entered. The positive effect of this voltmeter is the ability to monitor technological processes based on pulsed effects of carrier voltage. 3 hp f-ly, 3 ill.

Description

1

The invention relates to electrical measuring technology, can be used in systems for monitoring and control of technological processes, and is an improvement to the invention by the author. St. No. 1337791.

The purpose of the invention is to expand the functional capabilities by measuring the daily and current Q input signals both for each period of the carrier frequency and for a predetermined time interval.

On Aig .. 1 shows a 15 structured circuit; an IF voltmeter; in fig. 2 is a block diagram of the control unit; in fig. 3 is a block diagram of a volume counter, a sample.

A digital voltmeter contains a block 1 20 input amplifiers, the input of which is the first input of a digital voltmeter, an analog-to-digital converter: (A1SCH) 2, whose information input is connected to the output 25 of block 1 of input amplifiers, the second which is connected to the input of block 3 period detection, the first output of which is connected to the first input of the Fort-Schrovel frequency 4, output 0 of which is connected to the first input of the control unit 5, the second and third inputs of which are connected respectively (Gtvenno, to the second output of the period determination unit 3 and to the first output (Cycle stop). A1SC 2, the first output of control unit 5 is connected to the first control input (Start) ADC 2, pulse generator 6, the first and second outputs of which are connected to the second input of the frequency generator 4 and the fourth input of the control unit 5 , multiplier 7, sample size counter 8, first output and input

which are connected respectively d

to the fifth input and output of the control unit 5, the accumulation of the iron adder 9,

the information input of which is connected to the multiplier 7 output, the information output to the second information input A} C 2, and the first control input to the third code of the control block 5, the output register 10, whose information input is combined

, with information output A1SCH 2 and information input of intelligent switches 7, the first control input of the output

 the register is connected to the fourth output of the control unit 5, the second input

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0

five

the house of the counter 8 of the sample size by the n-second control input of the accumulating adder, the third control input of which is connected to the sixth; the output of the control unit 5, and the output information of the output .register

10 connected to the information output of a digital voltmeter, synchronization unit 11; ii, the first output of which is the second input of a digital voltmeter, the third input of which is combined with the third input of the output register Yu and the second input of the unit

11 synchronization, the third input and the first and second outputs of which are connected respectively to the second output

and the third and fourth inputs of the sample size counter 8, the third output of which is connected to the first control input of the multiplier 7, and the fifth input to the second control inputs of A1 Щ 2 and the multiplier .7, to the second output of the control block 5.

The control unit 5 comprises a trigger 12, the first input of which is the second input of the control unit 5, the second input is connected to the output of the trigger 13, the first input of the And 14 element and the third output of the control unit 5, and the output to the first inputs of the And 15 element and the trigger 16 , the second input of which is connected to the first inputs of the flip-flops 13 and 17 and the output of the counters. 18, the first, third and fourth inputs of the control unit are connected respectively to the third input of the trigger 16, the input of the single selector 19 and the second input of the trigger 13, the output of the trigger 16 is combined with the first input of the element 20, the second input of which is connected to the fifth input of the block 3 control and the second input element And 14, the output of which is connected to the input of the counter 18 and the first input of the element OR 21, the second input of which is connected to the second inputs of the element 15 and the trigger 17, the fourth input of the trigger 16 output, odnovrybrator 19 and the fourth output of the block5 of the control, the first, second, fifth and sixth outputs of the control unit are connected respectively to the outputs of the element AND 20, the trigger 17, the elements 15 AND and 21 OR.

The sample volume counter 8 comprises a counter 22, the input of which is the first, the input of the counter 8, the counter 23 of the first input of which is connected to

the second input of the counter 8 ,. the element OR 24, the first and second inputs and the output of which are connected respectively to the third and fourth inputs, and the first output of the counter 8, the second output of which is connected to the output

the counter 22 and the second input of the counter 23, the output of which is connected to the first input of the switch 25, the second Q; the output and output of which are connected to

nHTbiM input and the third output counter counts 8.

 RnoK 11 synchronization contains 15 | Element And 26, the first input of which is the first input of the synchronization unit 11, the delay element 27, the input of which is combined with the second input of the synchronization unit 11 and the first 20 input of the ICS) CHA Oi | EE or 28, the second input of which is connected to the output of the delay element 27, and the output to the first input of the AND 29 element, the second input of which is connected to the first input of the AND element 26 whose second input is connected to the third input of the synchronization unit, the third and fourth outputs of which are connected to exits

respectively, elements 26 and 29. The TT and LV voltmeter works in the following way.

.

Before starting work

selection of the measured parameter of the signal (mean square or mean square 30

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ratios voltage value) by putting into operation a specific memory area in the constant memory of multiplier 7, a preliminary voltmeter does not require a preliminary initial setting, because at the end of the measured signal period, after the next measurement result is issued condition. The measured voltage is fed to the input of the input amplifier of the unit 1, in which the voltage is brought to a certain level, required for the operation of A1Sh 2, depending on the selected measurement range. The period determining unit 3 serves to convert the input periodic signal of a complex form of the carrier frequency into a pulse train of the same period. Shaper A frequency produces pulses with a frequency equal to

55

N

t

,

Q

5 0 5

0

five

0

five

five

where N is the sample size, i.e. the number of samples of the instantaneous values of the measured voltage for one period;

T is the period of the measured voltage. The operation of the format 4 frequency is clocked by a high-frequency signal from the generator 6 pulses. The signals from the outputs of the period determination unit 3, the frequency former 4, and the pulse generator 6 are starting signals for the control unit 5.

Initially, a sub-accumulation amount is performed. At the beginning of the next period of the input voltage, the signal from the output of the period determining unit 3 sets the first trigger 12, the signal from the output of which permits the installation of trigger 16. The nearest time pulse from the output of the frequency generator 4 triggers the trigger 16, the signal from the output of which allows the generator pulse output 6 pulses through the second element I 20 to the input of the start of the ADC 2. A bi-rien value of the measured voltage is sampled. At the end of the sampling, the termination signal A1SCh 2 ps-one-shot one-shot 19 drops the triggers 16 and 17.

In addition, the signal from the output of the single-vibrator 19 is fed to the counter 8. volume - sampling and through the element OR 21 - on a pump; 1 a 1 adder 9 as a signal to accumulate a new value of the next sample. The supply of clock pulses through AND 20 ceases. Since the first trigger 12 remains in the set state, when the frequency of the next pulse in the ADC 2 appears from the output of the shaper 4, the next sampling of the instantaneous value occurs, the drop adder 9 adds the next count to the previous sum, and the counter 8 of the sample size changes its state is 1. After the N-ro sampling cycle, the counter 22 is updated by changing the state of the counter 23 to 1, the overflow signal of which enters the input of the And element 26.

Processing of measurement results begins. The number N is chosen for the convenience of information processing as a multiple of base 2 in integer10.

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71597756

degree. If the voltage value is selected for each period of the carrier frequency, the Modulation signal at the second input of the digital voltmeter is not set, and the logic level in the static state at the third input of the digital voltmeter is indifferent. In this case, the overflow signal of the counter 22 through the element 26 AND and the element 24 OR sets the trigger 13, the signal from the output, which resets the trigger 12 and allows the passage of pulses through the element And 14. The signal from the output of the trigger 13 converts the shift register accumulating adder 9 in the shift mode , and each pulse at the output of the first element OR 21 shifts its contents-to the right 20 by one bit. The number of shifts is equal to the exponent of the number N. Thus, the averaging operation of the content of accumulating adder 9 It is via shear. The number of shifts is controlled by a counter 18, which, at the end of a series of shifts, flushes trigger 13 and raises triggers 16 and 17.

After the averaging operation is performed, the signal from the output of the trigger 17 transfers the ADC 2 to receive signals from accumulating adder 9, the switch 25 to receiving the number from the counter 23. As with the Unmodified Modulation signal, the contents of the counter 23 after the sum accumulation subcycle is equal to 1, then the input of the accumulating adder-9 receives the inverse value of the numbers from the output of the multiplier 7. When a zero sum is received, the accumulating adder 9 generates a transfer signal that stops the operation of A1 SCH 2. At the same time, the end of sampling signal Erez odnovib- operators. 19 resets the triggers 1b and 17 and, through element I 15, resets the third counter 23, the shift register of accumulating adder 9, and records the measurement result from its output to the output register 10. This completes the cycle of the voltmeter, waiting for the next pulse from the period determination unit 3.

YU

40

45

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55

 P

 KSHM is set to Modulation signal - then there is no transition to the sub-cycle of calculating results-Measurements when

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0 35

YU

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eight

overflow of counter 22, and the execution of the summation accumulation subcycle occurs similarly to the previously described one, with the difference that counter 23 accumulates a number of periods of the carrier frequency more than one. Go to the subcycle. the calculation of measurement results is performed by changing the levels at the second input of the synchronization unit 11 (Measurement signal). In this case, with the help of delay element 27 and edement 28, EXCLUSIVE OR form — a pulse, which, through element 24 OR, causes control unit 5 to perform a sub-cycle for calculating measurement results. The number of shifts is the same as in the described case. The signal at the third input of the output register 10 can indicate either the location of the final result (for example, by separately representing the values of the voltage of the phases of the pulse and the pause of modulated oscillations), or allowing the reception of information in some phase.

Thus, the proposed digital voltmeter allows measuring not only for each period of the carrier frequency, but also for specified time intervals of the modulation period. The resulting integral characteristics give a good idea of the parameters of technological processes based on impulse effects on the object.

Claims (4)

1. Digital voltmeter auth.St. No. 1337791, characterized in that, in order to expand its functionality, a synchronization unit is additionally inserted in it, the first and second inputs of the synchronization unit being respectively the second and third inputs of the digital voltmeter, the second input of the synchronization unit is connected to the third input output register, the second input of the sample size counter is connected to the fourth output of the control unit and to the second control input of the accumulator D of its adder, the third control unit which input is connected to the sixth output of the unit Regents, sec second and third sample-volume counter outputs are respectively connected to the third multiplier and unit vhoda.m synchronization, the first and second outputs of which are connected respectively to the third and fourth inputs of the sample volume counter, the fifth input of which is connected to the second output of the control unit., 2. A voltmeter according to claim 1, wherein the synchronization unit contains a delay element, an EXCLUSIVE OR element, the first and second elements AND, the first inputs of the first and second elements AND being combined and connected to the first input of the synchronizer unit, the second inputs are connected respectively to the third input of the synchronization unit and the output of the SPARK1-TSEEE element, and the outputs, respectively, to the first ten 15 whose input is connected to the output of the third element AND and the third input of the OR element, the third input of the second flip-flop is the first input of the block. A control, a one-shot input is connected to the third input of the control unit, and the output is connected to the second inputs of the first element AND, the third three and the OR element, the fourth input of the second trigger and the fifth output of the control unit, the output of the second trigger is connected to the first input of the second element I, the second input of which is combined with the second input of the third element I and the fourth input of the control unit, the second input of the fourth trigger is connected to the fifth input of the control unit, first, second. and the second outputs of the synchronization unit, 20 fourth and sixth outputs of which the second input of which is combined with the inputs of the delay element and the first input of the EXCLUSIVE OR element, the second input of which is connected to the output of the delay element. 3. A voltmeter according to claim 1, wherein the control unit contains first, second, third, and fourth triggers, one-oscillator, nepBbtfi, second and third elements AND, element OR, and a counter, the first input of the first the trigger is the second input of the control unit, the third output of which is connected to the output of the fourth trigger, the first input of the third element And the second input of the first trigger, the output of which is connected to the first inputs of the first element And the second trigger, the first inputs of the third and fourth, as well as the second input second trig e .rov connected to the output of the counter. connected respectively to the output of the second element And, the third trigger, the first element And and the element OR. 25 4. A voltmeter according to claim 1, of which there is a problem that the sample volume counter contains the first and second counters and the OR element, the first input of the sub30 unit is connected to the input of the first counter, the second input to the first input of the second counter, the third and fourth inputs, respectively, to the first and second inputs of the S1I element, the output of which is connected to the first output b 35 ka, the second output of which is connected with. the output of the first counter and HHD ohm, the second counter, output which is connected to the first input, d of the switch, the second input of which is connected to the fifth input of the block, and the output to the third output of the block. five the input of which is connected to the output of the third element AND and the third input of the OR element, the third input of the second trigger is the first input of the control unit, the input of the one-vibrator is connected to the third input of the control unit, and the output is connected to the second inputs of the first element AND of the third trigger and the OR element, the fourth input of the second trigger and the fifth output of the control unit, the output of the second trigger is connected to the first input of the second element AND, the second input of which is combined with the second input of the third element AND and the fourth input of the control unit The second input of the fourth flip-flop is connected to the fifth input of the control unit, first, second. 20 fourth and sixth outs of which connected respectively to the outputs of the second element And the third trigger, the first element And the element OR. 25 4. The voltmeter according to claim 1, of the first and second, is that the sample volume counter contains a switch, the first and second counters and the OR element, the first input of the unit 30 being connected to the input of the first counter, the second input to the first input of the second counter, the third and fourth inputs, respectively, to the first and second inputs of the element SH1I, the output of which is connected to the first output of the block, the second output of which is connected with. the output of the first counter and HHD ohm, the second counter, output which is connected to the first input, d of the switch, the second input of which is connected to the fifth input of the block, and the output to the third output of the block. Ot5l.5 Fg / g.2 B Measurement GSH: Editor N. Yatsola Compiled by E.Zverev Tehred M. Didyk Order 3050 Circulation 560 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 25 one 29 G / fl3i / .J Proofreader M.Sharoshi Subscription