SU475732A1 - Pulse amplitude demodulator - Google Patents

Description

one

The invention relates to the field of automation and telemechanics.

Amplitude-pulse demodulators are known, containing differentiating RC circuits, diodes and low-pass filters. In the known device, the charge / C-chain time constant is assumed to be sufficiently small to fully charge the capacitor during the pulse time, and the discharge time constant is chosen to ensure that the demodulation error is as low as possible.

To reduce amplitude errors, increase the measurement frequency of the monitored parameter (pulse frequency). But, each measurement of a parameter and transmission of its value over a distance consumes a certain amount of energy, therefore, switching to an increased measurement frequency requires a large expenditure of energy of the power source.

The aim of the invention is to improve the accuracy of the demodulation of the amplitude-pulse signals at a lower modulation frequency.

This goal is achieved in that the device input is connected to the input of the first cyclic switch and the input of the driver, the output of which is connected to the control input of the first four cyclic switches.

the input of the fifth cyclic switch and its control input through the delay circuit, as well as with the starting inputs of the generators; Each of the outputs of the first CPC switch is connected via the corresponding parallel-connected capacitors and switches to the device ground bus, the first output of this switch is also connected to the third inputs of the second and fourth cyclic switches and the second input of the third cyclic switch, the second output to the first inputs of the second and the fourth cyclic switches and the third input of the second cyclic switch, the third output - with the second inputs of the second and fourth cyclic switches and with the first input of the third cyclic switch, the outputs of the second and third cyclic switches are connected to the inputs of the comparison circuit, the output of which is connected to the inputs of the generators, the outputs of which are connected to the inputs of the summing unit, the third input of which is connected to the output of the fourth cyclic switch, and the output forms the output of the device The first output of the fifth cyclic switch is connected to the control input of the second key, the second output is the third key, and the third output is the first key.

lia fig. 1 shows a diagram of an amplitude-pulse demodulator; FIG. 2-plots for operation of the device.

The proposed amplitude-pulse demodulator contains cyclic switches 1--5; shaper 6; delay circuit 7, keys 8-10, comparison circuit 11, linearly increasing generator 12 and linear voltage generator 13, summing unit 14, capacitors 15-17, input 18 and output, device 19 and ground strip 20.

Positions i, II, III denote the order in which cyclic switching occurs at the input (output) of switches 1-5.

The operation of the amilite-pulse demodulator is carried out as follows.

In the initial position, when the input signal is absent, cyclic switches 1-5 are in state 1, Key 8-10 is closed, capacitors 15-17 are discharged, and therefore the output of summing unit 14 is parsed. When appearing at the input 18 of a non-periodic pulse signal modulated in amplitude but on the leading edge of the cervic emulsion, the driver 6 outputs a short positive pulse arriving at the control inputs of the switches 1-4 and working and (through the delay circuit 10) at the control inputs of the switch 5 and to the triggering inputs of geirativators 12 and 13. The passage through switch 5, the pulse opens the key 9, which is triggered by the duration of the pulse, short-circuits the co-detector 16, thereby preparing it to memorize the amylase magnitude output signal, and then returns to its original state. Switch 5 is switched to state P by acting and its control input by the same pulse, but delayed by time t. The delay must be greater than the duration of the emulsion emitted by the driver 6. The emuls from the output of the driver affecting the control inputs 2- 4, translates them into state II. At the same time, the voltage from the co-detector 17 (equal to the moment of the jump) is fed to the input of the summing unit 14. The positive value from the former does not change the state of switch 1. Condenser 15 through switch 1 in state 1 is charged to the amplitude value of the first input momentum. The voltage from the co-detector 15 through the switch 3 in state II is fed to the comparison circuit 11. Here, through the switch 2 in state II, the voltage is supplied from the capacitor 17. In the output of the comparison circuit, the voltage difference t / is-Un is separated. The difference signal of these voltages is applied to the control inputs of the generators 12 and 13. The sign (polarity) of this signal makes the selection of the generator to be started; The magnitude of the signal determines the steepness of the rise of the signal. The generator start-up is also produced by the impeller from shaper 6,

formed on the leading edge of the first input pulse: The coupling from the generator 12 or 13 is fed to the input of the summing unit 14, where it is added to the ionizer coming from the output of the switch 4. At the end of the first input pulse, the driver generates a negative pulse affecting the control input is switch 1, and the last hierarch goes to state II. When the input 18 of the second pulse is received, the shaper 6 generates a pulse coming through the switch 5, which is in the P state, and the control input of the key 10 on the front edge.

5 Using this key, the coiderizer 17 is produced and prepared for memorizing the amplitude of the next (third) pulse. The same impulse from the imaging unit 6 acts on the control inputs of the switches 2,

0 3, 4, translated them into state III. At the same time, through switch 4 to summing unit 14, voltage is supplied from capacitor 15. Through switches 2, 3 to comparison circuit I1, iodine is transmitted from capacitors 16 and 15. The output signal of comparison circuit t / jg-f / ig is fed to control the inputs of the generators 12 and 13. These generators are also triggered by a pulse from the former 6. The output generator of the generator 12 is 13 and the input of the summing unit 14 is idle. At the end of the input pulse, the former 6 generates a sigal to the hierarchy.

5 switch 1 to state III. When the input on input 18 of the third imiuls is used, the circuit will work in a similar way.

Thus, the difference of amplitudes is always distinguished at the output of the circuit AND of the comparison.

0 outputs of the last two pulses. By

the greatness and sign of this difference is triggered

one of the generators 12 or 13, voltage

 from whose output iaaaaaa sum

block 14, where it is added to the amplitude of the previous 5 and the last pulse. The modulated signal envelope after demodulation is a broken line (see FIG. 2).

Subject and discoveries

for an immodul demodulator containing five cyclic switches, three co-sensors, three keys, linearly returning and linearly generating generators

A shaper, a comparison circuit, a delay circuit and a summing unit, characterized in that, in order to increase the demodulation accuracy, the device input is connected to the input of the first cyclic switch and the driver input, the output of which is connected to the control input of the first four cyclic switches, the input of the fifth cyclic switch and its control input through a delay circuit,

as well as triggering inputs of generators; Each of the outputs of the first cyclic switch is connected via corresponding capacitors and switches connected in parallel to the device ground bus, the first output of this switch is also connected to the third inputs of the second and fourth cyclic switches n to the second input of the third cyclic switch, the second output to the first inputs of the second and the fourth cyclic switches and the third input of the second cyclic switch, the third output with the second inputs of the second and fourth cyclic switches and with the first input of the tricyor-cyclic switch, the outputs of the second n of the third cyclic switches are connected to the inputs of the comparison circuit, the output of which is connected to the inputs of the generators, the outputs of which are connected to the inputs of the summing unit, the third input of which is connected to the output of the fourth cyclic switch, and the output forms the output device, the first output of the fifth cyclic switch is connected to the control input of the second key, the second output is the third key, and the third output is the first key.

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