RU1781639C - Digital meter of duration of single electrical pulses - Google Patents

Description

the output of the pulse shaper, the outputs of the first and second elements OR are connected respectively to the installation input and the reset input of the trigger, the direct and inverse outputs of which are connected respectively to the first inputs of the first and second elements AND, the second inputs of which are connected respectively to the outputs of the comparison device and inverter and the outputs - with the first second inputs of the third OR element, the input of the analysis unit is connected to the input of the sampling and storage device, the information input of which is connected to the first input subtracting amplifier and is the third input of the analysis unit, the second input of the analysis unit is connected to the input of the pulse former, the output of which is connected to the first input of the third AND element, the second input of which is connected to the output of the third OR element, and the output is the output of the analysis unit, the fourth input of the analysis unit is connected by the second input of the subtracting amplifier, the outputs of the attenuator and the driver of the voltage module are connected respectively to the input of the reference voltage and the information input of the comparison device, the output to It is connected to the inverter input.

In FIG. 1 is a structural diagram of a digital meter: FIG. 2 - block diagram of the analysis unit; in FIG. 3 illustrates the principle of dividing the pulse repetition period from the sawtooth generators into zones.

The digital duration meter comprises a sterte pulse former 1, a stop pulse former 2, a standard pulse former 3, elements 4-6 OR, respectively, from first to third, first and second sawtooth voltage generators 7 and 8, first and second zero-elements 9 and 10, the comparator 11, the first to third pulse shapers 12-14, respectively, an AND element 15, a pulse counter 16, an analysis unit 17 and a fourth OR element 18. The output 19 of block 2. The output 20 of block 3, the output 21 of block 7, the output 22 of block 8, the output 23 of block 13, the output 24 of block 14, the output 25 of block 12 are connected respectively to the inputs of the analysis block one through seven.

The analysis block 17 (Fig. 2) contains elements 26-28 OR from the first to the third, respectively, a trigger 29, a sampling and storage device 30, an attenuator 31, a subtracting amplifier 32, a voltage modulator 33, a comparison device 34, an inverter 35 shaper 36 pulses,

Elements 37-39 And from the first to the third, respectively.

The meter works as follows.

Shapers 1 and 2 of start and stop pulses generate short pulses corresponding to the beginning and end of the measured pulse at a given voltage level. The start pulse through the OR element 4 is fed to the first input of the sawtooth voltage generator (SPS) 7, which is started and generates a linearly increasing voltage. After the stop pulse arrives through the OR element 6 to the second input of the generator 7, it switches to the formation of a linearly falling voltage. When it reaches zero, the zero-organ 9 is activated and the pulse from the driver 12 through element 4 again starts the GPN 7 to form a linearly increasing voltage. For GPN 8, the role of the start pulse is played by the stop pulse, and the role of the stop pulse by the pulse from the output of the shaper 12. The steepness of the linearly but increasing and linearly falling voltages of the generators 7 and 8 is the same, therefore, sequences are formed at their outputs triangular pulses, shifted relative to each other by half the repetition period, which in turn is equal to twice the duration of the measured pulse. These sequences are fed to the inputs of the comparator 11, which is triggered when these values are equal. Thus, at the outputs of the shapers 12, 13, and 14, pulse trains are formed which at the output of the OR element 5 form a train of pulses with a repetition period equal to half the duration of the measured pulse.

This sequence and a pulse of standard duration from the output of the driver 3, triggered at the moment of arrival of the measured pulse, are fed to the inputs of the element And 15. During a pulse of standard duration, the pulses from the element 5 pass through the element And 15 and are counted by the counter 16 pulses. The measured duration is determined from the expression: T D / N, where T is the duration of the measured pulse, N is the number of pulses recorded by the counter 16, D is the duration of the standard pulse.

The period of succession of the triangular pulses from the generators 7 and 8 is divided (Fig. 3) into 8 zones of equal duration, and the zones with odd numbers begin from the moment of the formation of one of the pulses at the output of the OR element 5, and

even-numbered zones end with the arrival of the next pulse of this sequence. A specific feature of the meter operation is the addition of an additional pulse to the total number of pulses of the counter 16 in the case when the moment of termination of a pulse of standard duration falls into one of the even zones. For odd zones, an additional pulse is not generated.

In order to reliably determine the zone number (even or odd) in which the phase of the signals is located with the GPU analysis unit 17 (Fig. 2), the following factors are analyzed; which of the blocks worked last - 7, 8 or 11; the ratio of the difference between the instantaneous voltage values from the generators 7 and 8 and the maximum voltage (Fig. 2 of the generator 7). Zones one through eight correspond to the following values of the indicated parameters:

Moreover, | AUl (Unm - UrriH2 I, Umax / 2 is half the maximum value of the voltage of the generator 7.

Block 17 determines the zone in which the voltage of the ГПН 7 is located at the moment of the end of a pulse of standard duration and depending on its number (even and odd) determines the need to add a pulse to counter 16. The analysis block works as follows:

The voltage from output 21 of GPN 7 is supplied to the information input of device 30 for retrieval and storage. At the moment of arrival of the stop pulse from output 19 of unit 2, the instantaneous (maximum) voltage value from generator 7 is stored in device 30. The voltage Umax from the output of device 30 divided by the attenuator 31 twice. The inputs of the subtracting amplifier 32 receive signals from generators 7 and 8. At the output of block 32, a voltage equal to the instantaneous difference of the input voltages is generated, and fed to the input of the former of voltage module 33, the output of which is the signal I D UI, Signals from the outputs blocks 31 and 33 are supplied respectively to the input of the reference voltage and the information input of the comparison device 34. at the output of which a single signal is generated at I AU / Umax / 2 and zero at AU Umax / 2, inverted at block 35.

When the driver 12 or 13 is triggered, the trigger 29 through the AND 25 or 23 elements and the OR element 26 is set to one state, and the signal from the former 14 through the OR element 27 is set to zero, determining the last triggered block-9, 10 or 11.

The signals from the outputs of blocks 29, 34 and 35 are supplied to the elements And 37 and 38. At the output of the And 37 element, a single signal is generated when the signal from the GPS 7 is in the second or sixth zones, and a single signal is generated from the output of the element 38 when the signal from the GPS 7 located in the fourth or eighth zones (Fig. 3). Thus, at the output of the OR element 28, a single signal is formed when the signal from the GPS 7 is in even zones.

At the end of a pulse of standard duration, a shaper 36 is triggered along its trailing edge and generates a polling pulse for the And 39 element, the output of which generates a signal when the signal from the generator 7 is in the even zone at this moment. This signal through the OR element 18 is added to the counter 16, and also sets the trigger 29 to its original state, after which the device is ready to process the next measured pulse.

The initial state of the meter nodes: blocks 16, 29 are in the zero state, the signal level from the generators 7 and 8 is also zero,

Since there is no signal from the generator 8 during the first triangular pulse from the generator 7, the comparator 11 is activated during the first triangular pulse, which requires the meter 16 to be installed in the state with the contents to ensure constant accuracy across the entire measurement range before starting the measurement. equal to one.

Thus, the error of the claimed device is maximally equal to one eighth of the period of the triangular pulse from the generator 7, which is two times lower than the absolute error of the main invention; the accuracy of this invention is two times higher, with the same speed of the device.

Claims (1)

1. A digital meter of single electric pulse durations comprising a start-pulse shaper, a stop-pulse shaper, a standard-duration pulse shaper, three OR elements, two sawtooth voltage generators, an And element, a counter, a first zero-organ and a first pulse shaper connected in series connected in series to a comparator and a third pulse shaper, connected to a second zero-organ and a second pulse shaper, the inputs of the shapers a start pulse, a table pulse and a pulse of standard duration are connected to the input of the meter, and the outputs are connected respectively to the first inputs of the first and third elements OR and the first input of the element AND, the output of the first OR element is connected to the first inputs of the sawtooth voltage generators and the second element OR, output of the third element OR - to the second inputs of the sawtooth voltage generators and the second OR element, the third input of which is connected to the output of the second pulse shaper, and the output -with the second input of the element And, the output of the first sawtooth generator is connected to the input of the first zero-organ and the first input of the comparator, the output of the second sawtooth voltage generator to the input of the second zero-organ and the second input of the comparator, the outputs of the first and second pulse shapers are connected respectively to the second inputs of the first and third elements OR, characterized in that, in order to improve the accuracy of measurements at the same speed, an analysis unit and a fourth OR element are introduced into it, and the outputs of the stop-pulse and standard-duration pulse shapers, sawtooth generators, shaper her pulses are connected to the corresponding inputs of the analysis unit, the first and second inputs of the fourth OR element are connected respectively to the outputs of the AND element and the analysis unit, the output of the fourth OR element is connected to the counting input of the pulse counter. 2, Meter pop 1, characterized in that the analysis unit contains three elements OR, three elements AND, trigger, after- seperately connected sampling and storage device and attenuator, serially connected subtracting amplifier and voltage module driver, comparison device, inverter and pulse generator, the first and second inputs of the first OR element being the seventh and fifth inputs of the analysis unit, the first and the second inputs of the second OR element are connected respectively to the sixth input of the analysis unit and the output of the pulse shaper, the outputs of the first and second elements of the OR are connected respectively to the installation trigger input and reset input, the direct and inverse outputs of which are connected respectively to the first inputs of the first and second AND elements, the second inputs of which are connected respectively to the outputs of the comparison device and the inverter, and the outputs are connected to the first and second inputs of the third OR element, the first input the analysis unit is connected to the control input of the sampling and storage device, the information input of which is connected to the first input of the subtracting amplifier and is the third input of the analysis unit, the second input of the analysis unit is connected to a pulse former, the output of which is connected to the first input of the third AND element, the second input of which is connected to the output of the third OR element, and the output is the output of the analysis unit, the fourth input of the analysis unit is connected to the second input of the subtracting amplifier, the outputs of the attenuator and the voltage driver connected respectively to the input of the reference voltage and the information input of the comparison device, the output of which is connected to the input of the inverter gz Yash.8 / / W 7 / / / H / / /