SU423095A1 - DIGITAL MEASURING CENTER RECTANGULAR VIDEO IMPULSES - Google Patents

Description

one

This invention relates to radio measurements.

The device can be used in pulse radar when determining the coordinates of targets, in special television when determining the coordinates of objects, and in other areas of radio electronics.

Digital gages of the center of rectangular video pulses are known, including a delay line, a counting pulse generator, an AND circuit, a pulse shift register, reversible counters, a comparison circuit.

The known meter has a maximum measurement error of the center of the video pulse, which is different for the period of the following counting pulses, since it is not known in advance how many counting pulses will fit into the duration of the video pulse studied.

The purpose of the invention is to improve the accuracy of measuring the center of the body of the video pulse and reducing the number of elements.

The proposed digital meter is characterized in that it includes three triggers, a second and a third AND circuit, and a cumulative counter. In this case, the first input of one of the triggers is connected to the “I” circuit, the second input is connected to the output of the cumulative counter and the first input of the second trigger, and the output to another “I” circuit, which in turn is input

connected to the input of the first circuit "And and the output of the third trigger, and the output to the input of the counter, the output of the first circuit" And, as well as to the input of the reversible counter for addition: the second trigger input is connected to the comparison circuit and the output to the second circuit “And, which is connected by the output to the input of the reversible counter for subtraction, and the input to the output of the generator of counting pulses and the input of the third trigger.

FIG. 1 shows a structural diagram of the meter; in fig. 2 - time diagrams. The meter consists of a counting generator

pulses 1, coincidence circuits "And 2-4, triggers 5-7, accumulative counter 8, reversible counter 9 and comparison circuit 10.

The principle of measuring the center of a rectangular video pulse, explained by temporary

The diagrams of FIG. 2 is as follows. A rectangular video impulse whose center is to be determined (Fig. 2a) is fed to an AND 2 circuit. This is also where the pulses come from trigger 5, which halves the frequency of the counting pulses generator 1 (Fig. 2). An AND 2 circuitry performs time quantization of a rectangular video pulse (FIG. 26). The quantized video impulse comes from here to a cumulative counter 8 and a reversible counter 9 (Fig. 2c). At the end of the video impulse, its falling edge overturns trigger 6, stopping the flow of pulses on the reversible counter input 9. Counting counters 8 continue to receive counting pulses (Fig. 2d).

When the cumulative counter 8 overflows, an output of an impulse is formed at its output, which overturns the control triggers 6 and 7, opening access to the downstream counter's subtracting input to 9 counting pulses following the double frequency (Fig. Id, and closing the counting pulses to access the accumulative counter eight.

After time from the center of the video impulse, the reversible counter 9 is nullified, and a standard impulse is formed at the output of the comparison circuit 10 (Fig. 2e, k), corresponding to the center of the video impulse. The same impulse brings the counters and triggers to zero, driving the circuit to its initial state.

L1 Hz, corresponding to the center of the video pulse under investigation (Fig. 2a), is determined from

/ c G - Gz,

where (Fig. 2g) and (Fig. 2 / s) are the moments of the issuance of standard pulses by the comparison circuit 10;

  T32 (Fig. 2g, k) is the constant delay time of a standard pulse from circuit 10 relative to the center of the video pulse being studied.

From the timing charts of FIG. 2 that the time of issuance of a standard pulse by the circuit 10 always corresponds to the true center of the video pulse under investigation, minus the delay time Tc required by the meter for information processing.

Reading a video pulse recorded in a reversible counter of the number of quantized pulses with counting pulses followed by a double frequency improves the accuracy of measuring the center of the video pulse and eliminates the error associated with the parity of the number of quantized pulses in the video pulse.

The proposed meter contains a smaller number of elements due to the use of a cumulative counter instead of the shift register in times, where n is

t + logs n

the duration of a video pulse, expressed by the number of a pulse of time quantization; t is the number of control cells.

P ip e dme t. Invention

A digital meter for the center of rectangular video pulses, containing the first AND circuit, to the output of which is connected via

reversible counter comparing circuit, and a counting pulse generator, characterized in that, in order to improve the measurement accuracy and reduce the number of elements, three triggers are introduced into it, the second and third circuits

"And and cumulative counter, and the inputs of the first trigger are connected to the input of the first circuit" And to the output of the cumulative counter, and the output - with one of the inputs of the second circuit "And, the second input of which is connected to

the output of the second trigger and the input of the first circuit "And the output of the second circuit" And connected to the input of the cumulative counter and the output of the first circuit "And, one input of the third circuit" And connected to the generator output

counting pulses and to the input of the second trigger, the second input to the output of the third trigger, and the output to the subtracting input of the reversible counter, while the inputs of the third trigger are connected to the output of the cumulative counter and to the input of the comparison circuit.

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FIG. one