TTL level nanosecond pulse pair generation circuit

Abstract

The invention discloses a TTL (transistor-transistor logic) level nanosecond pulse pair generating circuit, which belongs to the field of optical fiber sensing systems and comprises a TTL level square wave generator, a first nanosecond pulse generator, a second nanosecond pulse generator, a time delay circuit, a pulse signal router and a frequency divider, the TTL level square wave generator is connected with the time delay circuit and the frequency divider; the frequency divider is connected with the pulse signal router; the time delay circuit is simultaneously connected with the first nanosecond pulse generator and the second nanosecond pulse generator; the first nanosecond pulse generator is connected with the pulse signal router; the second nanosecond pulse generator is connected with the pulse signal router; the pulse signal router outputs two groups of pulse signals. According to the invention, two relatively wide laser pulse pairs with a certain width difference can be used for respectively detecting, and then the detected signals of the two laser pulse pairs are compared, so that narrow pulse detection is realized under the condition of maintaining a relatively high signal-to-noise ratio of the photoelectric detector, and the photoelectric detector is simple, convenient and beneficial to popularization.

Description

Technical Field

[0001] The present invention relates to the field of fiber optic sensing systems, and specifically to a TTL-level nanosecond pulse pair generation circuit. Background Art

[0002] The fiber optic sensing system is an important symbol to measure a country's informatization level. The fiber optic sensing system has been widely used in military, national defense, aerospace, industrial and mining enterprises, energy and environmental protection, industrial control, medicine and health, metrology and testing, construction, household appliances and other fields, and has a broad market. The fiber optic has a wide working frequency band and a large dynamic range, is suitable for remote measurement and control, and is an excellent low-loss transmission line; under certain conditions, the fiber optic is particularly easy to accept the loading of the measured quantity or field, and is an excellent sensitive element; the fiber optic itself is not charged, has a small volume, a light mass, is easy to bend, has good anti-electromagnetic interference and anti-radiation performance, and is particularly suitable for use in harsh environments such as flammable, explosive, severely restricted space and strong electromagnetic interference.

[0003] In a distributed fiber optic sensing system, it is necessary to modulate continuous laser into pulsed laser with a width of nanosecond level and inject it into the sensing fiber. A narrow pulse width has a high spatial resolution, but has a low signal-to-noise ratio. When the used pulse is narrow to a certain width, the photodetector loses its function and what is detected will be a mass of noise. For this reason, researchers have invented the pulse pair detection method: using two relatively wide laser pulses with a certain width difference to detect respectively, and then comparing the signals detected by the two. Under the condition of maintaining a high signal-to-noise ratio of the photodetector, narrow pulse detection is realized. Therefore, a circuit is needed to implement the above functions. Summary of the Invention

[0004] Regarding the above problems existing in the prior art, the purpose of the present invention is to provide a TTL-level nanosecond pulse pair generation circuit to solve the problems put forward in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A TTL-level nanosecond pulse pair generation circuit includes a TTL-level square wave generator, a first nanosecond pulse generator, a second nanosecond pulse generator, a delay circuit, a pulse signal router and a frequency divider. The output end of the TTL-level square wave generator is connected to one end of the delay circuit and one end of the frequency divider at the same time;

[0007] The other end of the frequency divider is connected to the control port 3 of the pulse signal router;

[0008] The other end of the delay circuit is connected to the input end of the first nanosecond pulse generator and the input end of the second nanosecond pulse generator at the same time;

[0009] The output terminal of the first nanosecond pulse generator is connected to the input port 1 of the pulse signal router;

[0010] The output terminal of the second nanosecond pulse generator is connected to the input port 2 of the pulse signal router;

[0011] The signal output port 4 of the pulse signal router outputs two groups of pulse signals.

[0012] As a further solution of the present invention: the TTL square wave generator is used to generate a TTL square wave pulse with adjustable frequency.

[0013] As a further solution of the present invention: the TTL square wave generator is internally provided with a frequency setting module, and the frequency setting module is used to adjust the frequency of the TTL square wave pulse.

[0014] As a further solution of the present invention: the frequency divider is used to divide the square wave pulse generated by the square wave generator.

[0015] As a further solution of the present invention: the frequency divider is internally provided with a frequency division setting module, and the frequency division setting module is used to adjust the frequency division setting.

[0016] As a further solution of the present invention: the delay circuit is used to perform a specific delay on the pulse signal generated by the TTL square wave generator to ensure the stable working state of the pulse signal router.

[0017] As a further solution of the present invention: the delay circuit is internally provided with a delay setting module, and the delay setting module is used to set and adjust the delay time.

[0018] As a further solution of the present invention: the first nanosecond pulse generator and the second nanosecond pulse generator are used to generate two TTL pulse signals with adjustable pulse widths.

[0019] As a further solution of the present invention: both the first nanosecond pulse generator and the second nanosecond pulse generator are internally provided with a pulse width setting module, and the pulse width setting module is used to adjust the pulse width setting.

[0020] As a further solution of the present invention: the signal output port 4 of the pulse signal router outputs two groups of pulse signals that are alternately output with equal numbers and consistent intervals.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The present invention can use two relatively wide laser pulse pairs with a certain width difference for separate detection, and then compare the signals detected by the two. Under the condition of maintaining a high signal-to-noise ratio of the photodetector, narrow pulse detection is achieved, which is simple and convenient and conducive to popularization. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. 1 is a schematic block diagram of a TTL - level nanosecond pulse pair generation circuit disclosed in an embodiment.

[0024] Figure 2 FIG. 2 is a schematic diagram of pulses in a TTL - level nanosecond pulse pair generation circuit disclosed in an embodiment.

[0025] In the figures, the reference numerals are: 1. TTL - level square - wave generator; 2. First nanosecond pulse generator; 3. Second nanosecond pulse generator; 4. Delay circuit; 5. Pulse signal router; 6. Frequency divider. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "connected", and "connected" should be understood in a broad sense; for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0028] Please refer to Figure 1-2 , a TTL - level nanosecond pulse pair generation circuit, including a TTL - level square - wave generator 1, a first nanosecond pulse generator 2, a second nanosecond pulse generator 3, a delay circuit 4, a pulse signal router 5, and a frequency divider 6. The output end of the TTL - level square - wave generator 1 is simultaneously connected to one end of the delay circuit 4 and one end of the frequency divider 6;

[0029] The other end of the frequency divider 6 is connected to the control port 3 of the pulse signal router 5;

[0030] The other end of the delay circuit 4 is simultaneously connected to the input end of the first nanosecond pulse generator 2 and the input end of the second nanosecond pulse generator 3;

[0031] The output end of the first nanosecond pulse generator 2 is connected to the input port 1 of the pulse signal router 5;

[0032] The output terminal of the second nanosecond pulse generator 3 is connected to the input port 2 of the pulse signal router 5;

[0033] The signal output port 4 of the pulse signal router 5 outputs two sets of pulse signals;

[0034] The TTL level square wave generator 1 is used to generate TTL square wave pulses with adjustable frequency. There is a frequency setting module inside the TTL level square wave generator 1, and the frequency setting module is used to adjust the frequency of the TTL square wave pulses.

[0035] TTL levels provide a standardized voltage level that enables signals to be transmitted reliably between different circuits and components. Due to the high noise tolerance of TTL levels, it can resist power supply fluctuations and external interference to a certain extent, helping to maintain signal integrity and keep the signal clear even during long-distance transmission or in a noisy environment. This standardized level ensures that signals do not generate errors due to voltage fluctuations during transmission. Due to the standardization of TTL levels, digital circuits produced by different manufacturers can be compatible. This means that circuits using TTL levels can be easily connected to other circuits using the same level standard without additional level conversion circuits. The high noise tolerance of TTL levels helps to maintain signal integrity and keep the signal clear even during long-distance transmission or in a noisy environment. In addition, due to the standardization of TTL levels, circuit designers can more easily design and implement digital circuits, relying on the characteristics of TTL levels to predict the behavior of the circuit, thus simplifying the design process.

[0036] The frequency divider 6 is used to divide the square wave pulses generated by the square wave generator 1 to achieve absolutely equal numbers of two sets of pulses. There is a frequency division setting module inside the frequency divider 6, and the frequency division setting module is used to adjust the frequency division setting. A pulse frequency divider can divide an input high-frequency signal into multiple low-frequency signals according to a certain ratio to meet the signal requirements of different circuits. Through the frequency division function, a pulse frequency divider can divide the input signal into output signals with different frequency ranges, enabling each frequency band of the signal to be processed specifically. In a frequency synthesizer, a pulse frequency divider can combine multiple frequency signals to achieve multi-band signal transmission or reception. A pulse frequency divider achieves the purpose of frequency division by connecting flip-flops in series or in parallel, resulting in a specific delay effect on the signal. Specific implementation methods include accumulator frequency dividers, divide-by-two frequency dividers, frequency multipliers, and prescalers, etc.

[0037] The delay circuit 4 is used to perform a specific delay on the pulse signal generated by the TTL square wave generator 1, so as to ensure that after the working state of the pulse signal router is stable, the pulse signals generated by the first nanosecond pulse generator 2 and the second nanosecond pulse generator 3 appear at the input end of the pulse signal router 5, and the pulse signal router 5 performs pulse signal selection. The delay circuit 4 is internally provided with a delay setting module, and the delay setting module is used to set and adjust the delay time.

[0038] A circuit that can delay a pulse signal by a certain time. There are many ways to delay a pulse signal. In addition to being implemented with electronic circuits, cables, artificial transmission lines, ultrasonic delay lines, and charge-coupled devices can also be used to delay pulse signals. Delay circuits can reduce the malfunction of circuits when the load changes or the ambient temperature fluctuates. Especially in protection circuits, delay circuits can ensure that the circuit is not immediately cut off when the current surges or fluctuates, thereby reducing the situation of repeated cutting off, and improving the stability and reliability of the circuit. By precisely controlling the delay time, delay circuits can ensure the synchronous and stable transmission of signals, avoid signal jitter and noise, and thus improve the overall performance of the circuit. In an automated control system, delay circuits can implement timing and triggering functions and reduce the occurrence of misoperations. In many practical applications, delay circuits often do not actually delay the input pulse signal itself, but only generate another new pulse signal after a required period of time as the delayed output pulse.

[0039] The first nanosecond pulse generator 2 and the second nanosecond pulse generator 3 are used to generate two TTL pulse signals with adjustable pulse widths. There is a pulse width setting module in both the first nanosecond pulse generator 2 and the second nanosecond pulse generator 3. The pulse width setting module is used to adjust and set the pulse width and outputs to the two input ports of the pulse signal router 5, namely input port 1 and input port 2. The nanosecond pulse generator can generate various pulse signals from low frequency to high frequency and from low voltage to high voltage by adjusting circuit parameters. These pulse signals can be used to test key performance such as the transient response, frequency response, and voltage tolerance of electronic devices. The nanosecond pulse generator can precisely control the width and amplitude of the pulse to meet different test requirements. By adjusting these parameters, various complex pulse signals such as spike pulses, square wave pulses, and slow ramp waves can be simulated to test the response ability of electronic devices to different pulse signals. The pulse signal generator is usually equipped with a filter to remove clutter and noise in the circuit, improving the purity and reliability of the pulse signal. This is crucial for electronic devices that require high-precision testing. The nanosecond pulse generator can drive external devices such as electronic components and mechanical components by outputting pulse signals. This makes the pulse signal generator have broad application prospects in fields such as industrial automation and robot control. The pulse signal generator can perform various measurements and tests by outputting pulse signals, such as measuring circuit parameters and performance. At the same time, it can also be used as a reference signal source and timing source to provide an accurate time reference for fields such as radar, communication, measurement, and control.

[0040] The pulse signal router 5 is used to select the input signal and alternately output an equal number of pulse signals with consistent intervals from the signal output port 4. The pulse signal router can identify network addresses and select the best path for data transmission. It dynamically updates through the internal routing table to guide communication to select the best path, ensuring efficient data transmission and avoiding network congestion. The router can achieve load balancing, transmitting data packets to multiple networks, improving network performance and reliability. It can reasonably allocate bandwidth according to data requirements to ensure that high-demand applications such as games and video conferencing are given priority.

[0041] The square wave generated by the adjustable frequency square wave generator 1 controls the repetition frequency of pulse pair generation and is divided into two paths: One path passes through the delay (with a delay of 30 ns to 60 ns) circuit 4 and is further divided into two paths. One of these paths simultaneously goes to two nanosecond pulse generators with adjustable pulse widths, namely the first nanosecond pulse generator 2 and the second nanosecond pulse generator 3, and two pulses with different pulse widths are generated simultaneously. For example, one pulse width is 10 ns and the other is 11 ns. These two pulses go to the two input terminals of the pulse signal router 8, namely the input port 1 and the input port 2. The other path goes to the control port 3 of the pulse signal router 5 after passing through the frequency divider 6. The high and low levels of the control signal respectively correspond to the output of the two pulse signals, thereby achieving an equal number of output pulses for the two pulses.

[0042] For example: The square wave generator generates a square wave of 10 kHz. When octal frequency division is adopted, the width changes every four pulses. The role of the delay circuit is to ensure that the nanosecond pulses are generated after the routing of the pulse router is stably established, so as to ensure the integrity of the pulse signal. This circuit uses TTL level. The TTL level provides a standardized voltage level, enabling signals to be reliably transmitted between different circuits and components. Since the TTL level has a relatively high noise tolerance, it can resist power supply fluctuations and external interference to a certain extent, which helps to maintain the integrity of the signal.

[0043] The present invention can use two relatively wide laser pulse pairs with a certain width difference for separate detection, and then compare the signals detected by the two. Under the condition of maintaining a relatively high signal-to-noise ratio of the photodetector, narrow pulse detection can be achieved, which is simple and convenient and conducive to popularization.

[0044] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0045] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A TTL level nanosecond pulse pair generating circuit, characterized in that: It comprises a TTL level square wave generator (1), a first nanosecond pulse generator (2), a second nanosecond pulse generator (3), a delay circuit (4), a pulse signal router (5) and a frequency divider (6), wherein the output end of the TTL level square wave generator (1) is simultaneously connected to one end of the delay circuit (4) and one end of the frequency divider (6); The other end of the frequency divider (6) is connected to the control port 3 of the pulse signal router (5); The other end of the delay circuit (4) is simultaneously connected to the input end of the first nanosecond pulse generator (2) and the input end of the second nanosecond pulse generator (3); The output end of the first nanosecond pulse generator (2) is connected to the input port 1 of the pulse signal router (5); The output end of the second nanosecond pulse generator (3) is connected to the input port 2 of the pulse signal router (5); The signal output port 4 of the pulse signal router (5) outputs two groups of pulse signals.

2. A TTL level nanosecond pulse pair generating circuit according to claim 1, characterized in that: The TTL level square wave generator (1) is used to generate TTL square wave pulses with adjustable frequency.

3. A TTL level nanosecond pulse pair generating circuit according to claim 2, characterized in that: The TTL level square wave generator (1) is internally provided with a frequency setting module, and the frequency setting module is used to adjust the frequency of the TTL square wave pulse.

4. A TTL level nanosecond pulse pair generating circuit according to claim 3, characterized in that: The frequency divider (6) is used to divide the frequency of the square wave pulse generated by the square wave generator (1).

5. A TTL level nanosecond pulse pair generating circuit according to claim 4, characterized in that: The frequency divider (6) is provided with a frequency division setting module, and the frequency division setting module is used to adjust the frequency division setting.

6. A TTL level nanosecond pulse pair generating circuit according to claim 5, characterized in that: The delay circuit (4) is internally provided with a delay setting module, and the delay setting module is used to set and adjust the delay time.

7. A TTL level nanosecond pulse pair generating circuit according to claim 6, characterized in that: The delay circuit (4) is internally provided with a delay setting module, and the delay setting module is used to set and adjust the delay time.

8. A TTL level nanosecond pulse pair generating circuit according to claim 7, characterized in that: The first nanosecond pulse generator (2) and the second nanosecond pulse generator (3) are used to generate two TTL pulse signals with adjustable pulse widths.

9. A TTL level nanosecond pulse pair generating circuit according to claim 8, characterized in that: The first nanosecond pulse generator (2) and the second nanosecond pulse generator (3) are both provided with a pulse width setting module, and the pulse width setting module is used to set and adjust the pulse width.

10. A TTL level nanosecond pulse pair generating circuit according to claim 9, characterized in that: The signal output port 4 of the pulse signal router (5) outputs two groups of pulse signals which are pulse signals of equal number and consistent intervals output alternately.

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