SU731578A1 - Stochastic voltmeter - Google Patents

Description

one

The invention relates to electrical measuring equipment and can be used to measure the average, among the most complex (average in modulus) values of voltages in a stochastic way.

A device is known that contains a sensor whose output is connected to the input of the measuring converter, the output of which is connected to the first input of the comparator, the second input to the synchronizer output, the third input to the output of the reference voltage generator, and the output to the first input of a two-channel counter, the second input which is connected to the input of the source of the clock (oior) frequency 1. This device is directly intended for measuring the average values of the voltage under study.

However, it has a constant resolution (sensitivity) on the level, and, therefore, the measurement of the values of nanoparticles, which varies in a wide diaamic range, is not advisable with its help.

The closest in technical solution to the proposal is a device containing a clock pulse generator, a voltage-probability converter, two counters, a dividing unit, a digital reading device, the input of which is connected to the output of the dividing unit, the first and second inputs of which are connected to the outputs of the first and the second counter, respectively, the input of the first counter is connected to the output of the voltage converter — the probability, the first input of which is the input of the device as a whole, and is connected to the input of the generator action pulses, the output of which is connected to the second input of the inverter and li-lipie - the probability and the input of the second counter 2. In this device, the voltage converter - the probability is made in the form of three separate blocks: a reference measurement device, an amplifier and a generator of uniformly distributed random variables, and clock generator is included in the generator unit of uniformly distributed random pulses.

20 The disadvantage of this device is the inconsistency of the relative measurement error of the instantaneous values of the input signal, which naturally leads to a decrease in the frequency of the average values of the input signal.

25 beeps.

The purpose of the invention is to improve the accuracy of the transformed and calculated mean and mean (mean) modulated voltage.

30 The goal is achieved by the fact that

into a device containing serially connected pins 5nvertor, frequency multiplier, test number counter, count number of counts, AND block whose outputs are the outputs of the device as a whole, and information inputs are connected to the outputs of the reversible counter, transducer - likelihood, the control input of which is connected to the output of the frequency multiplier, additionally introduced are a series of amplifiers, a series of comparators, a comparison block with zero, a switch, an encoder, an order code generation block, an order register, a decipher op, key, full-wave rectifier, the latter input is connected to the input of the imaging unit and the first input of the block compared to zero, the second input of which is connected to ground and the output through the key - to the control input of the reversible counter, the information inputs of which are connected to the outputs of the decimator, informational the input of the converter connected to the output - probability and control of the inputs - to the outputs of the register of the order whose inputs are connected to the outputs of the block of the formation of the code of the order, the outputs of the connected to the control inputs of the switch and to the outputs of the encoder, the control input of which is connected to the output of the test charge counter, and the information inputs to the outputs of switch rooms, the first inputs of which are combined and connected to the reference voltage source, the second inputs to the outputs of amplifiers, the inputs the latter are combined and connected to the output of the full-wave rectifier, and the outputs of the amplifiers are also connected to the information inputs of the switch, the output of which is connected to the information input of the converter - probability.

In the drawing a structural diagram of a stochastic voltmeter.

The device contains a full-wave rectifier 1, a comparison with zero circuit 2, a driver 3, a series of amplifiers 4, a switch 5, a frequency multiplier b, a series of comparison circuits 7, a test number counter 8, an encoder 9, a switch 10, an order code generator And, the register is of the order of 12, the counter of the number of counts is 13, the transducer is voltage - probability 14, the decoder 15, the reversible counter 16 and the block of elements I 17.

The input dynamic range of the voltmeter can be defined as the interval of change of the input magnitude, within which the measurement takes place with a relative value b, not exceeding the allowable bdop. From the definition of relative error for known devices (b)

1-, with greatness b limited

-n

above the size

. (,) max it /

k AiaKC ---, (i)

where and are the values for measuring the total value of Uti - the true value of the measured value;

DS / is the quantization step on ref. The analysis of expression (1) says that the fulfillment of the last condition can be ensured only by changing (decreasing) the value, i.e.

 If

(- /

The following can serve as a quantitative indicator of the moment of changing the value of the TO.

() ma, l

(2)

With hardware realnzatsin onncajfnogo algorithm is easier to use

(3)

... ,, -. Before .

 Un-f

In the general case, the B.chichina K depends on /

and

(four)

o-op- /

In the proposed device, the specified algorithm is implemented with a nominal set of agents with a transmission coefficient (d-e, Cmax), a set of identical comparators that compare Ux-Ki values with ЕО, the Ux comparison unit with a zero value, which determines the sign of the input signal.

In the proposed device, the normalization of the operatives is performed and the use of pushers with a transfer coefficient multiple to the base of the number system is normalized. The latter means that the mantissa of the individual will always be no less than l / q and, accordingly, the relative stability will be insignificant. Thus, using the floating point com- plete representation of the information format (order of the mantissa) allows to increase the accuracy (methodical and actual) of the converted input values. But such a form of information representation is supposed to be used in a complex arithmetical process that would allow for a time-consuming, leveled-out operation of the norms before su.mmmiropy (subtraction). In the proposed device, this difficulty is overcome by introducing a dust generator, which, depending on the code value, connects the voltage converter to the output — the probability is the corresponding input of the reversible counter, which H3 changes the weight of the elementary increment of the result.

The operation of the device in the mode of measuring the mean modulo is as follows.

In the initial state, all counters 8, 13, 16 and the register of the order 12 are set to zero. Key 5 is open. When a device Ux is applied to the input device, the shaper 3 generates certain signals at the moments when Ux passes through a zero value, highlighting the iriode of the signal under study. The signals from shaper 3 are fed to frequency multiplier 6, which produces V clock pulses, the frequency of which is determined by the non-period Ux. At the same time, the input signal is fed to the input of block 2 compared to zero, which forms the signal corresponding to the instantaneous value of the input signal , as well as to the input of the two-full rectifier 1, which realizes the function 1 (x) (x), i.e. a signal equal to the absolute value of the input signal is generated at the output of the output 1.

Thus, a signal of the same sign (only positive or only negative) is sent to the inputs of usnptel 4, the transmission coefficients of which are multiples of the base of the number system. The amplifiers are distributed in terms of augmentation of the coefficients of the neredachp Kj from / (, i; ai to / Slgax. Comparators 7 compare the values of Ux-Kj with the reference voltage

lmax

about

(с1 - o1; svaniya system schpq

slit, further for unambiguity believe that (7 2). At the same time, at the outputs of some of the Comparators 7, and the inputs of which Ux-Kj, Eu, a zero level signal is generated, and the rest of the signal is single (i.e., 00 ... 011 ... 1). The granulation (transition pz zero to one) of output signals uniquely determines the required transmission coefficient Ki. Thus, with the arrival of the first clock pulse, the encoder 9 (on the analysis of the output sigals of the comiators 7) determines the necessary transmission coefficient Kij, the magnitude of which is determined by the condition of the normalized one. In this case, by means of the switch 10, a voltage equal to the product UxKij is connected to the input of the voltage converter. The magnitude of the gain of the selected amplifier is converted to the Nordic code;, :: MjiiODtiino: about 311 Chac: 6v; using the I block. The generated code is entered into the register in the order of 12. Starting from the second to the nth clock cycle, the driver 14 forms the probability code of the U-xi Kij well, which is available to the information input of the airframe 15. The latter is in priority from The code of the code also allows the current "s. of pulses to the corresponding input

reversible counter 16. Previously, the register codes of the order of 12 and the number of bits of counter 16, to which random signals are received, coincide. After the end of the nth clock cycle ((.g-1) is the number of tests required to achieve a given statistical accuracy), the generated position code L / xi appears in the counter 16. The last nz of each series but imulses overflows with the count of the number of tests 8. The spontaneous output in the counter of the number of counts 13 n sends the encoder 9 to the input of the encoder 9 to analyze the output sigals of the comparators 7. With this signal, the encoder selects (when passing through) a new compiler with the required factor. for the next instantaneous value of Lxi + t. Then, the code of the choice of the non-random coefficient (1 -} - 1) -th input value is entered into the register and the code, and the probability code of the mantissa is formed in the next n cycles.

.vi + l Ki + lj.

On the basis of the last of this series of pulses, the partial summation of Uxi-rUxi + i- is completed. Then, the device operated similarly to the t-th non-performing counter 8 (t is the number of samples in the specified interval L / x). the counterrun of counter 8 and the counter-completion of counter-13 occurs. This overflow signal is fed to the equalizing input of the AND / I circuit, and the output of which is generated (transmitted from counter 16) by the input signal | t7 | cp. The mode of measurement of the average Ucp differs from that described above only in that the key 5 closes the value: the output of the block 2 versus zero - the control input of the reversing counter 16, which transmits information about the sign Uxi- Signals that are not available to the control input of the counter 16 There are some of his works - complex or subtraction. Thus, after the expiration of .V cycles () from counter 16, the code of the algebraic sum (taking into account the sign) of the instantaneous values of the input value U is read.

The normalization operation, i.e. dividing the obtained result by L, is absent, since N is chosen under the condition of L.

In this case, a rigidly fixed position in the output code determines the value of the measured parameters.

Thus, the introduction of additional b. Yukov n functional links allows you to increase the accuracy of the measurement, and the required values of million, in 3aBncHN OCTH from the required requirements, to increase the speed or extend the diaamic range of the input of the input signals of higher computational accuracy. All this expands the range of tasks solved by similar devices.

Claims (2)

1. Thumphart. Use of probabilistic principles in new measuring devices. Electronics, July 15, 1975, p. 33-34. 2.Ornatsky P.P. Automatic Measurements and Devices Kiev, “Higher Scales, 1973, p. 534 (prototype).