SU1459456A1 - Device for selecting signals of changing amplitude with time - Google Patents

Abstract

The invention relates to nuclear spectrometry, and can be used in measurement technology. The purpose of the invention is to increase the reliability of the selection of signals of varying amplitude according to the rise time. To achieve this goal, the proposed device introduces high-speed analog-to-digital converter and digital selection schemes, which allow to obtain a time resolution for determining the rise time of the input signal, independent of the rise time and equal to the minimum sampling period of the analog-digital converter. A device for selecting signals of varying amplitude in the rise time contains amplitude discriminator 1, driver 2 with a following threshold, high-speed analog-to-digital converter 3, single-oscillator 4, generator 5 clock pulses, two data registers 6 and 7, counter 8, transmission circuit 9 , the first element of comparison of codes 10, the second counter 11, the second element of comparison of codes 12, shaper of output signals 13. 1 Il. with S (L

Description

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The invention relates to nuclear spectrometry and can be used for identifying types of ionizing radiation and subsequent selection of the main radiation from the accompanying background according to their distinctive features - different signal rise times.

The input signal is fed to the inputs of amplitude discriminator 1, a driver 2 with a servo threshold, and an analog-digital converter 3. The aim of the invention is to increase whether the amplitude of the input signal exceeds the selectivity of the selection signal of the amplitude discriminant amplifiers varying amplitudes time of their rise.

. The drawing shows the block diagram of the device for selection

1, then the control input of the imaging unit 2 with the following threshold receives a signal permitting the operation of the imaging device 2. Otherwise, the device is blocked at the input, thereby protected from noise signals from the detectors and from loading the input stages of the device with signals from the ammunition signals varying amplitudes with respect to rise time.

The device contains amplitude

discriminator 1, the input of which is owed by a 20 pitch below the trigger threshold, is amplified by the input of the device connected to. of the discriminator 1. By dropping the input of the former 2 with the following threshold and the input of the high-speed

the output signal of the amplitude discriminator 1 starts the one-oscillator 4, the output signal of which stops the outputs of the counters 8, 11 to the zero state.

analog-to-digital converter 3, and the output of the amplitude discriminator 1 is connected to the control input of the imaging unit 2 with the following threshold and the input of the one-oscillator 4. The output to the driver 2 with the following threshold is connected to the starting input of the generator 5 clock pulses, the output of which is connected to the clock inputs of the analog -digital converter 3, the first data register 6 and the second data register 7, as well as to the inputs of the first counter 8 and the transmission circuit 9. The outputs of both data registers 6, 7 are connected respectively to the first and second groups of inputs of the first element of the comparison of codes 10, the output of which is connected to the second input of the passband 9. The output of the passband is connected to the input of the second of this and the preceding result of the analog-digital conversion. At the moment of time when the input signal increment between adjacent clocks of analog-to-digital preVX MRX

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Go counter 11 ,. the output of which is connected to the stop input of the generator 5 45 does not exceed the quantum-clock step. The vanilla reset inputs (set to O) of the first counter h (U 8 and the second counter 11 are connected to the one-shot 4 output. The outputs of the first counter 8 are connected to the first group of inputs of the second comparison element of the codes 12, the second group of inputs of which is the time selection control input increase

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where n is the number of binary bits of the analog-to-digital conversion of bodies 3,

The previous conversion result code, recorded in the second data register 7, coincides with the current conversion code 55 entered in the first data register 6. In this case, the output voltage of the first comparison unit 10 creates a logical difference in the output voltage that permits.

device input signals. The output of the second element of comparison of the codes 12 is connected to the input of the driver of the input signals 13, the output of which is the output of the device.

The device for selecting b signals of varying amplitude over the rise time works as follows.

The input signal is fed to the inputs of the amplitude discriminator 1, the former 2 with the following threshold and the analog-digital converter 3. If the amplitude of the input signal exceeds the threshold amplitude discriminator

whether the input signal amplitude exceeds the amplitude discriminative threshold

1, then the control input of the imager 2 with the following threshold receives a signal permitting the operation of the imager 2. Otherwise, the device is blocked at the input, thereby protected from noise signals of the detectors and from loading the input stages of the device with signals from the amperage below the trigger threshold. a bad discriminator 1. Delta

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the output signal of the amplitude discriminator 1 starts the one-oscillator 4, the output signal of which stops the outputs of the counters 8, 11 to the zero state.

The output signal of the running driver 2 with the following threshold is triggered by a generator of 5 clock pulses, the output signals of which are controlling the amplitude into converting the amplitude into a code by an analog-to-digital converter 3. With each clock pulse the code of the input amplitude

35, the signal is transferred to the first data register 6, and its previous state is transferred to the second data register 7. At the inputs of the first element of the comparison of codes 10, information is simultaneously received

40 this and the previous result of analog-digital conversion. At the time when the input signal increment between adjacent clocks of the analog-digital converter does not exceed the quantization step h (U

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45 educator will not exceed the quantization step h (U

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where n is the number of binary bits of the analog-to-digital conversion of bodies 3,

The previous conversion result code, recorded in the second data register 7, coincides with the current conversion code 55 entered in the first data register 6. In this case, the output voltage of the first comparison unit 10 creates a logical difference in the output voltage that permits.

5 clock pulse generator signals passing from the input of the transmission circuit 9 to its output and respectively to the input of the second counter 11. Counter 11. counts the number of pulses from the transmission circuit 9 to a certain number K, after which its output forms a signal stopping the clock pulse generator 5 .

The first counter 8 since the start of the 5 clock pulse generator with the signal from driver 2 with the following threshold and until it was stopped by the output signal of the second counter 11 counted the number of clock pulses in this time interval proportional to the rise time tn of the input signal. If N is the number of clock pulses recorded by the first counter 8, then n NT, where T is the period of the signals of the clock generator 5 and, accordingly, the sampling period of the analog-to-digital converter 3. If the number N represented at the output of counter 8 is binary

Claims (1)

The invention The device for selecting a variable amplitude signal with a rise time, containing an amplitude discriminator, the input of which is in the input of the device is connected to the input of the former with the next horn, and the output signal generator, the output of which is the output of the device characterized in that, in order to increase the reliability of the selection of signals of varying amplitude in the rise time, a high-speed analog-to-digital converter is inputted into it, whose input is connected with the device input, and the nojjr outputs are connected to the first data register, the outputs of which are connected to the inputs of the second data register and the first group of inputs of the first code element, the second group of inputs of which are connected to the outputs of the second data register, and the output of the first code comparison element connected to the input of the passband, the second the code that matches or exceeds the set-, 30 input of which is connected to the input in advance, in digital terms, the rise time of the input signal I (the two numbers are compared in binary code by the second comparison element 12), then the output of the second comparison element is code 12 12. The logical difference of the output voltage that triggers the output signal of the signals is 13. Ta -, in a CIM manner, signals with a rise time equal to or greater than T "given at the input of the selection control (second group of inputs of the second comparison element 12 codes) are accompanied by further amplitude analysis of logic With a single signal from the output of this device, allowing a multichannel amplitude analyzer to operate in a coincidence mode when registering, for example, the amplitude spectrum of the probes, to signals only with t f / TC. The specified number K 5-10 reflects the multiplicity of repetitions of code combinations at the input of the first comparison element 10 kb s and serves as the first counter and clocked inputs of the analog-digital converter and both data registers are connected to the output of the clock generator 35 pulses, the start input of which is connected to the output of the forwarder with the next threshold, the control input of which is connected to the output of the amplitude discriminator connected by its 40 is output to the input of a single vibrator, the output of which is connected to the reset inputs of the first counter and the second counter, which is connected by its input to the output of the transmission circuit and 45 by the output to the stop input of the clock generator, and the outputs of the first counter are connected to the first group of inputs of the second code time element, the second group of inputs 50 of which is the input of the selection control of input signals, by the rise time, and the output of the second code comparison element is connected to the input of the output signal generator 55 Nalov. ten 59456 criterion of achievement by the input signal of the amplitude value. Claims A device for selecting signals of varying amplitude with respect to the rise time, comprising an amplitude discriminator whose input is an input of a device connected to a driver input with a following threshold, and an output driver, whose output is a device output, characterized by the fact that In order to increase the reliability of the selection of signals of varying amplitude with respect to the rise time, a high-speed analog-to-digital converter has been introduced into it, the input of which is is connected to the input of the device, and the outputs of the nojjr are connected to the first data register, the outputs of which are connected to the inputs of the second data register and the first group of inputs of the first code comparison element, the second group of inputs of which are connected to the outputs of the second data register, and the output of the first code comparison element is connected to the input of the transmission circuit, the second 15 20 25 Whose 30 input is connected to the input the first counter and the clocked inputs of the analog-digital converter and both data registers are connected to the output of the clock generator pulses, the start input of which is connected to the output of the forma- tor with the following threshold, the control input of which is connected to the output of the amplitude discriminator connected by its an output from the one-shot input, the output of which is connected to the reset inputs of the first counter and the second counter, which is connected by its input to the output of the pass-through circuit and the output to the stop input of the generator, clock pulses, and the outputs of the first counter are connected to the first group of inputs of the second element of comparison, codes, the second group of inputs which is the input of the selection of input signals, by the rise time, and the output of the second code comparison element is connected to the input of the output signals generator.