RU2146061C1 - Signal-strength meter - Google Patents

Abstract

FIELD: metering strength of pulse signals statically distributed in time. SUBSTANCE: meter has pulse generator, counter, register, digital-to-analog converter, integrator, and AND gates; counter outputs are connected to inputs of register whose outputs are connected to inputs of digital-to-analog converter. Introduced in addition are time-interval counter, shift control circuit, and shift parameter setting elements; complementing input of time-interval counter and first input of first AND gate are connected to pulse generator output; time-interval counter output is connected to inverting input of second AND gate whose first input functions as that of signal-strength meter, to second input of first AND gate whose output is connected to register synchronizing input and to first input of shift control circuit, and to second input of shift control circuit also connected to outputs of shift parameter setting elements. First output of shift control circuit is connected to R inputs of time-interval counter and counter whose complementary input is connected to output of second AND gate, and its second output is connected to control input of register. Output of digital-to-analog converter is connected to integrator whose output functions as analog output of device. EFFECT: improved accuracy of measuring low variations in signal strength on the background of high intermediate frequency of input pulses. 2 cl, 1 dwg

Description

 The invention relates to equipment for automation systems for scientific research in nuclear physics and related fields and can be used to measure the intensity of pulsed signals statistically distributed over time.

 Numerous examples of implementation of digital type intensimeters are known. Such devices usually consist of an event counter, a generator, a time counter and an arithmetic device that performs the operation of averaging the results over several measurement cycles / 1, 2 /. These devices are characterized by high measurement accuracy, good reliability and repeatability, but with continuous monitoring of intensity with a small measurement time cycle, visual perception of information becomes impossible, because the inertia of human vision does not allow us to distinguish between rapidly changing numbers on the indicator board. In addition, the digital indication of the measurement results, in contrast to scale instruments, has less clarity and convenience, while a single glance at the scale instrument allows one to obtain both quantitative and qualitative characteristics of the signal under study.

 A known intensimeter, which is based on the principle of charging a capacitor with a current proportional to the average frequency of the input pulses, and measuring the value of the accumulated charge / 3 /. Presentation of the results in this device is performed using a galvanometer, the scale of which is graded in the number of pulses per second. The intensimeter has acceptable accuracy and controls, manipulating which you can remove the constant component of the signal under study and observe only a variable that varies from measurement to measurement, part of the input signal. However, devices of this type are difficult to configure, their implementation is complicated by the need for careful selection of high-precision and thermostable capacitors and resistors.

 The closest in technical essence to the present invention is a pulse repetition rate to DC voltage converter / 4 /, consisting of a pulse generator, counter, register, digital-to-analog converter, control unit, initial setting unit, comparator, decoders, integrator and several elements This device allows not only a digital representation of the intensity measurement results, but also when connecting an appropriately calibrated galvanometer to the output of the digital-to-analog converter, allows you to observe the results on a scale-type indicator. However, as noted earlier, digital indication is inconvenient for the visual perception of information, and when observing the measurement results on a scale indicator of this intensimeter at a high average frequency of input pulses, it is difficult to notice small fluctuations in intensity, which is important when adjusting the equipment or the sample under study in an ionizing radiation beam .

 The claimed invention improves the accuracy of measuring small changes in intensity against a background of a high average frequency of input pulses.

 This is achieved due to the fact that in the intensimeter containing a pulse generator, counter, register and digital-to-analog converter, integrator and AND elements, the counter inputs are connected to the inputs of the register, the outputs of which are connected to the inputs of the digital-to-analog converter, a time counter, a shift control circuit, and bodies for setting the shift parameters, and the counting input C of the time counter and the first input of the first element And are connected to the output of the pulse generator, the output of the time counter is connected to the inverse input of the second of the And element, the first input of which is the input of the intensimeter, to the second input of the first And element, the output of which is connected to the synchronization input C of the register and to the first input of the shift control circuit, and to the second input of the shift control circuit, also connected to the outputs of the shift parameter setting organs , the first output of the shift control circuit is connected to the inputs R of the time counter and counter, the counter input C of which is connected to the output of the second element And, and its second output is connected to the control input of the register, in addition, the digital output The analog-to-analog converter is connected to an integrator, the output of which is the analog output of the device.

триггера и вход

счетчика сдвигов являются вторым входом схемы управления сдвигами, выходы счетчика сдвигов соединены с входами цифрового компаратора, другие входы которого подключены к выходам органов задания параметров сдвига, выход которого подключен к входу R триггера и является первым выходом схемы управления сдвигами, вторым выходом которой является выход триггера.The shift control circuit preferably consists of a trigger, a shift counter, a digital comparator, and an And element, the inputs C of the trigger and a shift counter connected to each other and to the first input of the And element and are the first input of the shift control circuit connected to each other by an input

trigger and input

the shift counter is the second input of the shift control circuit, the outputs of the shift counter are connected to the inputs of a digital comparator, the other inputs of which are connected to the outputs of the organs for setting the shift parameters, the output of which is connected to the input R of the trigger and is the first output of the shift control circuit, the second output of which is the trigger output .

 The introduction of a time counter, a shear control scheme, and organs for setting the shear parameters with the corresponding relationships allows us to transform the measurement results in such a way that we can eliminate the unchanging, constant part and stretch the remainder of the monitored pulse input signal to the entire indicator scale, thereby increasing the accuracy of small measurements changes in intensity against the background of a high average frequency of input pulses.

регистра 8, счетный вход C которого соединен с выходом элемента И 3, а выходы подключены ко входам цифроаналогового преобразователя 9, выход которого подключен к интегратору 10, чей выход является аналоговым выходом устройства.The drawing shows a functional diagram of the proposed device. The intensimeter contains a pulse generator 1, the output of which is connected to the input C of the time counter 2 and to the first input of the element And 3. The output of the time counter 2 is connected to the second input of the element And 3, the inverse input of the element And 4, the first input of which is the input of the intensimeter, and with the shift control circuit 5. The output of the And 3 element is also connected to the shift control circuit 5, to which, in addition, the outputs of the shift parameter setting organs 6 are connected. The first output of the shift control circuit 5 is connected to the inputs R of the time counter 2 and the counter 7, input C is connected to the output of AND gate 4. The second output shifts the control circuit 5 is connected to the control input

register 8, the counting input C of which is connected to the output of the AND 3 element, and the outputs are connected to the inputs of the digital-analog converter 9, the output of which is connected to the integrator 10, whose output is the analog output of the device.

 The integrator 10 can be implemented, for example, as a capacitor, one output of which is connected to the output of the digital-to-analog converter 9, and the other output is grounded.

счетчика сдвигов 12. Выходы счетчика сдвигов 12 соединены со входами цифрового компаратора 13, другие входы которого подключены к выходам органов задания параметров сдвига 6. Выход цифрового компаратора 13 соединен со вторым входом элемента И 14, выход которого соединен с входом R триггера 11 и является первым выходом 17 схемы управления сдвигами 5, вторым выходом 18 которой является выход триггера 11.The shift control circuit 5 preferably consists of a trigger 11, a shift counter 12, a digital comparator 13, and an element 14. In this case, the counting inputs C of the trigger 11 and the shift counter 12, as well as the first input of the element And 14, are interconnected and connected to the first input 15 of the shift control circuit 5, the second input of which 16 is connected to the input D of the trigger 11 and the input

shift counter 12. The outputs of the shift counter 12 are connected to the inputs of the digital comparator 13, the other inputs of which are connected to the outputs of the organs for setting the shift parameters 6. The output of the digital comparator 13 is connected to the second input of the element And 14, the output of which is connected to the input R of the trigger 11 and is the first the output 17 of the shift control circuit 5, the second output of which 18 is the output of the trigger 11.

 The intensimeter can have both digital and analog representation of the measurement results. If it is necessary to have a digital representation of the results, a code 19 register is entered, the data inputs of which are connected to the outputs of the counter 7, and input C is connected to the second output of the shift control circuit 5. The outputs of the code 19 register are the digital outputs of the device and can be connected to a digital indicator. A scale indicator 20, for example a galvanometer, the scale of which is graduated in pulses per unit time, can be connected to the analog output of the intensimeter. The bodies for setting the parameters of the shift 6 can be performed, for example, in the form of a switch, the binary code of the number of shifts is removed from the output of which, or in the form of a program-controlled register.

 The intensimeter works as follows.

регистра 8, этот сигнал разрешает прием информации со счетчика 7. Запись информации происходит с получением на входе C регистра 8 первого импульса, поступающего с выхода элемента И 3. Этот же импульс, поступая через вход 15 на схему управления сдвигами 5, вызывает установку в состояние логической "1" триггера 11, что приводит к переводу регистра 8 в режим сдвига ранее записанной информации. На цифровом компараторе 13 выполняется сравнение кодов, поступающих с органов задания параметров сдвига 6 и счетчика сдвигов 12, выполняющего подсчет числа сдвигов. Синхронизация сдвигов информации осуществляется импульсами, поступающими с выхода элемента И 3 на тактовый вход C регистра 8. Сдвиг выполняется в сторону старших разрядов. Младшие по значению разряды передвигаются на позиции более старших разрядов; выдвигающиеся из регистра старшие разряды слова данных теряются. Освобождающиеся позиции младших разрядов заполняются нулями. Придание младшим разрядам слова данных большего веса и отбрасывание старших разрядов эквивалентно растяжке шкалы индикатора и исключению постоянной составляющей исследуемого сигнала. Результирующее слово с выходов регистра 8 поступает на входы цифроаналогового преобразователя 9, где преобразуется в токовый сигнал. Ток с выхода цифроаналогового преобразователя 9 через интегратор 10 подается на шкальный индикатор 20, шкала которого отградуирована в числе импульсов в единицу времени.A time counter 2, based on the clock signals received from the pulse generator 1, counts a predetermined time interval, after which a logical “1” signal is generated at its output, which goes to elements 3 and 4, as well as to input 16 of the shift control circuit 5. Thus, the further arrival of pulses from the input of the device through the And 4 element to the counting input C of the counter 7 is blocked and the passage of pulses from the pulse generator 1 to the input 15 of the shift control circuit 5 through the And 3 element is allowed. In the initial state, at the output 18 shift control circuit 5 there is a logical "0". Entering the control input

register 8, this signal allows the reception of information from the counter 7. The information is recorded by receiving at the input C of register 8 the first pulse coming from the output of element 3. The same pulse, coming through input 15 to the shift control circuit 5, causes the setting to logical "1" of the trigger 11, which leads to the transfer of register 8 in the shift mode of previously recorded information. On a digital comparator 13, a comparison is made of the codes coming from the organs for setting the parameters of the shift 6 and the counter of the shifts 12, which counts the number of shifts. Synchronization of information shifts is carried out by pulses coming from the output of the And 3 element to the clock input C of register 8. The shift is performed towards the higher bits. The least significant digits move to the positions of higher digits; leading high bits of the data word are lost from the register. The vacant low-order positions are filled with zeros. Giving the least significant bits of a word more data and discarding the higher digits is equivalent to stretching the indicator scale and eliminating the constant component of the signal under study. The resulting word from the outputs of the register 8 is fed to the inputs of the digital-to-analog converter 9, where it is converted into a current signal. The current from the output of the digital-analog converter 9 through the integrator 10 is supplied to a scale indicator 20, the scale of which is graded in the number of pulses per unit time.

 Clock pulses synchronizing the shift of the data word in register 8, coming through input 15 to the counting input C of the shift counter 12, are counted by this counter. When the specified number of shifts of the data word is completed, a logical “1” signal arises at the input of the AND element 14, which, when inputted to the input R of the trigger 11 of the shift control circuit 5, causes this trigger to be reset to the logical “0” state and, from the output 17 the shift control circuit 5 to the inputs R of the time counter 2 and counter 7 will cause the cleaning of both counters, thereby preparing the device for the next measurement cycle. In this case, register 8 is transferred to the data download (recording) mode, the passage of pulses through the And 3 element is prohibited, the passage of pulses from the intensimeter input through the And 4 element to the counting input C of counter 7 is allowed, the shift counter 12 is reset to zero in the shift control circuit. The device starts a new measurement cycle. Information is recorded in the code register 19 at the time the shift occurs at the output 18 of the shift control circuit 5 from the logical “0” state to the logical “1” state. The data at the outputs of the code register 19 remains unchanged until the end of the next measurement cycle. They exactly repeat the state of the outputs of the counter 7, do not undergo any transformations or shifts, carry complete information about the results of the completion of the measurement cycle and can be used, for example, for automated control of the process under study.

In the process of measuring the intensity, you can control the total intensity of the input pulses (in this case, no shifts of the data word on register 8 are performed) or if you want to "stretch" the indicator scale to 2, 4, 8,. . ., 2 ⁿ times by setting the corresponding shift parameters (shift by 1, 2, 3, ..., n digits, respectively). In this case, it becomes possible, with the exception of the constant, unchanging component of the signal, to observe on the indicator only the intensity of the input pulses varying from cycle to cycle. Since the part of the signal remaining after the exclusion of the constant component is “stretched” to the entire indicator scale, it becomes possible to more accurately measure small fluctuations in intensity against the background of the high frequency of the pulse signal under study.

References
1. A.P. Tsitovich. Nuclear Electronics. - M. Energoatomizdat, 1984, p. 176.

 2. A.S. USSR N 1778716, G 01 T 1/16, 1992

 3. Catalog of the company ORTEC, 1976, p. 141, Ratemeter 449.

 4. A.S. USSR N 1250977, G 01 R 23/09, 1976

Claims (2)

 1. An intensimeter comprising a pulse generator, a counter, a register, a digital-to-analog converter, an integrator, and AND elements, and the outputs of the counter are connected to the inputs of a register, the outputs of which are connected to the inputs of a digital-to-analog converter, characterized in that a time counter, a shift control circuit, and bodies for setting the shift parameters, and the counting input C of the time counter and the first input of the first element And are connected to the output of the pulse generator, the output of the time counter is connected to the inverse input of the second element And, the first input of which is the input of the intensimeter, to the second input of the first element And, the output of which is connected to the synchronization input C of the register and the first input of the shift control circuit, and to the second input of the shift control circuit, also connected to the outputs of the organs for setting the shift parameters, the first output of the shift control circuit is connected to the inputs R of the time counter and counter, the counting input from which is connected to the output of the second element And, and its second output is connected to the control input of the register, in addition, the digital output The analog-to-analog converter is connected to an integrator, the output of which is the analog output of the device.  2. The intensimeter according to claim 1, characterized in that the shift control circuit comprises a trigger, a shift counter, a digital comparator, and the I element, the inputs C of the trigger and the shift counter connected to each other and to the first input of the And element and are the first input of the shift control circuit interconnected input D of the trigger and input R of the shift counter are the second input of the shift control circuit, the outputs of the shift counter are connected to the inputs of the digital comparator, the other inputs of which are connected to the outputs of the organs for setting the shift parameters , the output of the digital comparator is connected to the second input of the element And, the output of which is connected to the input R of the trigger and is the first output of the shift control circuit, the second output of which is the output of the trigger.