SU660218A1 - Pulse stretcher - Google Patents

Description

the input pulse is bounded above the maximum value of the oscillation period of the shock excitation generator.

The purpose of the invention is to expand the range of durations of input pulses.

The goal is achieved by the fact that the pulse expander on the trigger device with two stable states has a start input and a return to the initial state, which also contains a pulse driver, two shock excitation generators tunable in frequency, a mixer, a low-pass filter , a zero-organ, with the shaper outputs connected to the inputs of shock excitation generators, the outputs of which are connected to the zero-organ input through a mixer and a low-pass filter, an And element, a reversible counter, is introduced, a decoder and an additional null organ, the input of which is connected to the output of one of the shock excitation generators, and the output to one of the inputs of the element I, the second input of which is connected to the input of the device.

The output of the element I is connected to summed by the input of a reversible counter, the setup input to the initial state of which is connected to one of the outputs of the pulse former, the subtracting input is connected to the output of the main zero-body, and the output of the reversible counter is connected to the return inputs the starting state of the trigger device and shock excitation generators.

FIG. 1 shows a pulse expander circuit; in fig. 2, a, and FIG. 3, a – W — timing diagrams that explain his work.

The pulse expander consists of the following elements: pulse shaper 1, which generates a pulse at the output 2 with a leading edge corresponding to the leading edge of the input pulse, and at output 3 a pulse with a leading edge corresponding to the falling edge of the input pulse; oscillators 4 and 5 of shock excitation tuned in frequency; mixer 6 oscillations of generators 4 and 5; trigger device 7, which forms the output signal; a low-pass filter 8 separating from the output of the mixer 6 oscillations of the difference frequency; a null organ 9 that emits a short pulse when the input voltage goes through zero from positive to negative values; a null organ 10 generating a short pulse when the input voltage goes from zero to negative values from positive values; element 11; a reversible counter 12, which is brought to the zero state by a pulse from output 2 of generator 1, input 13 of it is summing, and input 14 is subtractive; position decoder 15 -1 -1 reversible counter 12.

The device works as follows.

The input pulse with a duration of -Gvc (see Fig. 2, a) arriving at the input of the imager 1 is converted into two pulses, the beginning of one of which corresponds to the leading edge of the input pulse, and the beginning of the other to the trailing edge. Impulse, the beginning of which corresponds to the front

the front of the input pulse, starts the generator 4 of the shock excitation (see Fig. 2.6), and the pulse, the beginning of which corresponds to the trailing edge of the input pulse, the generator 5 (see Fig. 2, b) and the trigger device

7. The oscillations of the generators 5 and 4 with the frequencies coi and "2, respectively, create a beat voltage at the output of the mixer 6, from which the low-frequency filter extracts the voltage of the difference frequency by the low-pass filter 8

(Op - oscillations of the species.

and C. (w t-tUj -) - -COS (u))

(see Fig. 2, d). Differential voltage across zero voltage (with copi -

- co2 - 1 positive values

the negatives are fixed by the null organ 9, generating a short trigger pulse. The oscillations of the shock excitation generator 4 arrive at the input of the null organ 10, which separates a short pulse when the voltage goes from negative to positive values, i.e.

after the period T. If the duration of the input pulse is less than the period T, then the output pulse from the zero-organ 10 will not pass through the AND 11 element that is closed by that time to the summing input 13 of the reversing counter 12, which is reset to the initial state “O by the pulse from output 2 shaper 1. In this case, at TEXT, the output pulse 14 of the reversible counter 12 enters the subtracting input 14 of the reversible counter 12, which corresponds to the first zero crossing of the differential frequency voltage, and brings it to the -1 state. In this case, the decoder 15 outputs a short pulse returning the trigger device 7 to its initial state (and forming the falling front of the output pulse of the device), as well as generators 4 and 5. The duration of your output pulse is equal to the time interval between

impulse from the output 3 of shaper 1 and impulse from the exit of the null organ 9. Since

- 1 g - - OFF OF G VZS1

2Yur

The duration of the output pulse

Claims (2)

where / C is the expansion coefficient. By varying the oscillation frequency of the generators 4 and 5, it is possible to vary the magnitude of the expansion coefficient 65 over a wide range. If the duration of the input signal exceeds the oscillation period of the generator 4 T: BS.T (see Fig. 3c, b), the pulses from the output of the null organ 10 pass through the element 11 11 opened by the input pulse to the summing input 13 of the reversing counter 12 which fixes the number of integer periods T laid in the duration of TEC. Now the formation of the trailing edge of the output pulse is delayed by a proportional number of periods of the difference frequency, i.e., until the pulses from the output of the null organ 9 bring the reversing counter 12 to the position -1 (see Fig. 3, g-f ). As a result, the duration of the output pulse of the ri Tvx again appears to be proportional to the duration of the input signal of Tvyh Xth. The introduction of additional elements into the device ensures the versatility of the use of the proposed device, expands the range of durations of the converted pulses over a wide range and, therefore, the field of application of the device. DETAILED DESCRIPTION OF THE INVENTION A pulse expander on a triggering device with two stable states, having a start input and a return to the initial state, also comprising a pulse shaper, two shock excitation generators tunable in frequency, a mixer, a low-pass filter and a zero-organ, the shaper outputs are connected to the inputs of shock excitation generators, the outputs of which are connected to the null organ through the mixer and the low-pass filter, so that, in order to extend the range of the input pulses, elements I, a reversible counter, a decoder and an additional null organ, are inputted, the input of which is connected to the output of one of the shock excitation generators, and the output is connected to one of the inputs of the AND element, the second input of which is connected to the input of the device, and the output of the element I is connected to the summing input of the reversible counter, the setup input of which is in its initial state is connected to one of the outputs of the pulse former, the subtractive input is connected to the output of the main zero-body, and the output of the reversible through decoder counter connected to the inputs of return to the initial state of the trigger and the hammer drive generators. Sources of information taken into account in the examination 1. USSR author's certificate number 423236, cl. N OZK 5./04, 1972. 2. USSR Author's Certificate No. 341152, N OZK 5/04, 1970. entrance