PNP and NPN signal adaptive detection conversion circuit

Abstract

The invention discloses a PNP and NPN signal adaptive detection conversion circuit, which realizes automatic identification and conversion of signal types (PNP or NPN) through integration of a signal input end, an automatic detection circuit, a signal conversion circuit and an automatic control circuit module without manual intervention. The problem that in the prior art, equipment cannot work normally due to the fact that the types of the signal receiving ends are not matched is solved. The scheme is suitable for complex and frequently changing industrial environments, and the compatibility and the operation stability of the system are remarkably improved. Different from a scheme depending on manual selection of an output end in the prior art, the device disclosed by the invention directly performs automatic adaptation at the signal receiving end, so that the equipment connection and maintenance process is simplified, the system complexity and cost are reduced, and the device is particularly suitable for a scene in which multiple signal sources are mixed.

Description

Technical Field

[0001] The invention relates to the technical field of industrial automation control and electronic signal processing, and in particular to a PNP and NPN signal adaptive detection conversion circuit. Background Art

[0002] In industrial automation and electronic control systems, PNP and NPN signal types are widely used for signal transmission between sensors, PLCs, various circuit boards and other devices.

[0003] PNP signals are usually high level (24V), while NPN signals are low level (0V). Due to the inconsistency of signal types, compatibility issues often occur when connecting signals between devices, resulting in the inability to receive or transmit signals normally, affecting the normal operation of the device.

[0004] In the prior art, a common method to solve the incompatibility problem between PNP and NPN signals is to adjust the signal type by using a conversion device or a manual selection switch at the signal output end. This method relies on a conversion board or a manual selection switch on the sensor side, and the user manually selects the type of PNP or NPN signal to adapt to the needs of different receiving devices. However, this method has significant problems:

[0005] 1. Manual operation is prone to errors, especially in frequent sensor replacement or complex signal environments. The setting of manual selector switches is complicated and inefficient.

[0006] 2. Since the conversion is performed at the output end, the receiving end equipment needs to be constantly adjusted to match different signal sources, resulting in high complexity of system integration, increased operating costs and maintenance difficulties, and often causing great inconvenience due to incorrect models.

[0007] In order to avoid these problems, the industry has also tried to adjust the connection between PNP and NPN signals by presetting multiple conversion circuit boards or using dedicated conversion modules. However, such solutions are not only costly, but also occupy a large amount of hardware resources, increase the maintenance cost and equipment volume of the system, and increase the failure rate. In addition, since signal conversion mainly relies on fixed circuits, it cannot automatically adapt to changes in signal types and still cannot meet the needs of complex and changing signal environments.

[0008] Therefore, how to realize automatic detection and automatic conversion of the signal receiving end, ensure automatic adaptation of PNP and NPN signal types, and avoid manual intervention has become a technical problem to be solved by the present invention. Summary of the invention

[0009] The technical problem solved by the present invention is to provide a PNP and NPN signal adaptive detection conversion circuit in response to the defects existing in the above-mentioned prior art, so as to solve the problems of difficulty in docking PNP and NPN signals, complex manual operation, poor system compatibility and high maintenance cost in the prior art proposed in the above-mentioned background technology.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0011] A PNP and NPN signal adaptive detection conversion circuit, comprising:

[0012] Signal input terminal, used to receive input signal from PNP signal source or NPN signal source;

[0013] An automatic detection circuit, connected to the signal input terminal, capable of automatically detecting the type of the input signal and identifying whether the signal is a high-level PNP signal or a low-level NPN signal;

[0014] A signal conversion circuit is connected to the automatic detection circuit, and can automatically convert a PNP signal into an NPN signal, or convert an NPN signal into a PNP signal according to the signal type recognition result of the automatic detection circuit. When the receiving device only receives PNP, PNP is valid, and when the receiving device only receives NPN signals, NPN is valid, so as to adapt to the signal type requirements of the receiving device;

[0015] A signal output terminal, connected to the signal conversion circuit, outputting the converted signal to a signal receiving device;

[0016] The automatic control circuit module includes a plurality of integrated circuit units, which are respectively connected between the automatic detection circuit and the signal conversion circuit, and realizes the automatic conversion between PNP and NPN signals by switching the signal path through the built-in logic control;

[0017] As a further solution of the present invention, the automatic detection circuit includes:

[0018] A voltage comparison module is used to detect the voltage value received by the signal input terminal;

[0019] A signal determination unit, connected to the voltage comparison module, determines whether the input signal is a high-level PNP signal or a low-level NPN signal according to the detected voltage value;

[0020] The control output unit triggers the corresponding conversion path of the signal conversion circuit according to the output signal of the signal discrimination unit.

[0021] As a further solution of the present invention, the signal conversion circuit includes:

[0022] A multiplexer switch connected to the automatic detection circuit, and selecting a suitable signal path according to a signal type recognition result of the automatic detection circuit;

[0023] A level conversion circuit module, used for converting a PNP signal into an NPN signal, or converting an NPN signal into a PNP signal under a signal path selected by the multiplexer switch;

[0024] The signal stabilization output unit adjusts the converted signal to the required output level to meet the requirements of the signal receiving device.

[0025] As a further solution of the present invention, the automatic control circuit module includes:

[0026] A logic control unit, connected to the automatic detection circuit and the signal conversion circuit, with a built-in logic circuit for receiving the judgment result of the signal judgment unit;

[0027] The trigger mechanism activates the multiplexer in the signal conversion circuit through the logic control unit to complete the selection and conversion of the corresponding signal path.

[0028] As a further solution of the present invention, the signal output terminal further comprises:

[0029] Output adjustment module, used to perform level isolation, safety, stability and anti-interference processing on the converted signal to ensure that the output signal meets the level requirements of the receiving device;

[0030] The protection unit prevents signal instability caused by signal fluctuations or external interference, and improves the reliability of the device.

[0031] As a further solution of the present invention, the device further includes a level adaptation module, which is connected to the signal input terminal and the automatic detection circuit, and can automatically adjust the detection and conversion process according to the level of the input signal to ensure that the device can work normally under both high level and low level conditions.

[0032] The level adaptive module ensures the adaptability of the signal in various industrial control environments by automatically detecting and adjusting the input signal level. Both high-level and low-level signals can be reliably converted and input.

[0033] As a further solution of the present invention, the device adopts a single-line connection method, including:

[0034] A single-line input connection terminal is used for signal input and provides working voltage for the automatic detection circuit and the signal conversion circuit;

[0035] The single-wire electrical pathway realizes signal input detection and conversion output through electrical coupling, which reduces the installation and wiring complexity of the device.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. Unlike the existing technology which focuses on the conversion of the signal output end, the present application scheme is designed for the signal receiving end, and can automatically identify and adapt the signal, whether it is PNP or NPN signal. This feature completely solves the problem that the device cannot receive normally due to signal type mismatch, greatly optimizes the compatibility of industrial control systems, and is particularly suitable for complex scenarios where multiple types of signals are mixed.

[0038] 2. By automatically identifying the type of input signal (PNP or NPN), the signal conversion is automatically performed without manual intervention. It is suitable for complex and frequently changing signal environments, improving the convenience and reliability of system operation.

[0039] 3. The automatic detection and automatic conversion functions of the signal receiving end are realized, which solves the problem of difficulty in docking PNP and NPN signals in the prior art. Traditional solutions usually use a manual selection switch at the signal output end to adjust the signal type, which causes the signal receiving end to be unable to automatically adapt to different types of signal inputs, increasing the complexity of use and maintenance. The technology of the present application can directly and automatically identify and convert PNP and NPN signals at the signal receiving end without the need for additional manual adjustment or external conversion modules, fundamentally eliminating the docking obstacles caused by signal type mismatches, and greatly improving the compatibility of the equipment and the system integration efficiency. Through this solution, users do not need to worry about the problem of mismatching the signal type between the sensor and the receiving device, which significantly simplifies the signal docking process between devices and reduces the overall use and maintenance costs.

[0040] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 The figure is a schematic diagram of the automatic detection and conversion circuit of PNP / NPN signals of the present invention. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] See also Figure 1 In an embodiment of the present invention, a PNP and NPN signal adaptive detection conversion circuit includes:

[0045] Signal input terminal, used to receive input signal from PNP signal source or NPN signal source;

[0046] An automatic detection circuit, connected to the signal input terminal, capable of automatically detecting the type of the input signal and identifying whether the signal is a high-level PNP signal or a low-level NPN signal;

[0047] A signal conversion circuit is connected to the automatic detection circuit, and can automatically convert a PNP signal into an NPN signal, or convert an NPN signal into a PNP signal according to the signal type recognition result of the automatic detection circuit. When the receiving device only receives PNP, PNP is valid, and when the receiving device only receives NPN signals, NPN is valid, so as to adapt to the signal type requirements of the receiving device;

[0048] A signal output terminal, connected to the signal conversion circuit, outputting the converted signal to a signal receiving device;

[0049] The automatic control circuit module includes a plurality of integrated circuit units, which are respectively connected between the automatic detection circuit and the signal conversion circuit, and realizes the automatic conversion between PNP and NPN signals by switching the signal path through the built-in logic control;

[0050] The device realizes the integrated operation of signal detection, judgment and conversion through the electrical connection of the signal input terminal, the automatic detection circuit, the signal conversion circuit, the automatic control circuit module and the signal output terminal. The device triggers and automatically adjusts the circuit elements through electrical signals internally to realize signal type conversion without external intervention and a signal receiving terminal suitable for a variety of signal input environments.

[0051] As a further solution of the present invention, the automatic detection circuit includes:

[0052] A voltage comparison module is used to detect the voltage value received by the signal input terminal;

[0053] A signal determination unit, connected to the voltage comparison module, determines whether the input signal is a high-level PNP signal or a low-level NPN signal according to the detected voltage value;

[0054] The control output unit triggers the corresponding conversion path of the signal conversion circuit according to the output signal of the signal discrimination unit.

[0055] The automatic detection circuit detects the level state of the input signal through the voltage comparison module, and analyzes the output signal type in combination with the signal discrimination unit, thereby realizing automatic identification of PNP and NPN signal types, and the signal type judgment can be completed without user intervention.

[0056] As a further solution of the present invention, the signal conversion circuit includes:

[0057] A multiplexer switch connected to the automatic detection circuit, and selecting a suitable signal path according to a signal type recognition result of the automatic detection circuit;

[0058] A level conversion circuit module, used for converting a PNP signal into an NPN signal, or converting an NPN signal into a PNP signal under a signal path selected by the multiplexer switch;

[0059] The signal stabilization output unit adjusts the converted signal to the required output level to meet the requirements of the signal receiving device.

[0060] The signal conversion circuit automatically selects the signal path and completes the level adjustment according to the judgment result of the automatic detection circuit through the cooperation of the multi-way conversion switch and the level conversion circuit module, ensuring that the input signal can be correctly received and processed regardless of the PNP or NPN type.

[0061] As a further solution of the present invention, the automatic control circuit module includes:

[0062] A logic control unit, connected to the automatic detection circuit and the signal conversion circuit, with a built-in logic circuit for receiving the judgment result of the signal judgment unit;

[0063] The trigger mechanism activates the multiplexer in the signal conversion circuit through the logic control unit to complete the selection and conversion of the corresponding signal path.

[0064] The automatic control circuit module adopts hardware logic circuit to realize full automatic control from signal detection to signal conversion, without external manual operation, ensuring the efficiency and stability of the device in a variety of complex signal input environments.

[0065] The circuit principle of the present invention is as follows: the circuit is composed of a PNP transistor and an NPN transistor, a resistor, a voltage regulator diode, and a bidirectional photoelectric coupler. When the electrical appliance inputs a 0V / 24V voltage, the two transistors are cut off under the action of the bypass resistor. When the signal input end is high level or low level, such as a high level input, the circuit is a high level current through the resistor voltage regulator diode to the NPN transistor. At this time, the NPN transistor is turned on, and the current forms a loop through the bidirectional photoelectric coupler and the transistor. The bidirectional photoelectric coupler works, and the photosensitive transistor of the photoelectric coupler outputs a signal to the PLC or the required equipment. If the signal is low level, the PNP transistor current passes through the voltage regulator diode to the resistor to the signal line, the PNP transistor is turned on, the high level current passes through the transistor through the bidirectional photoelectric coupler and forms a loop with the signal low level 0V, the photoelectric coupler works, and the photosensitive transistor works to output a signal to the PLC or the required equipment. The photoelectric coupler is divided into NPN or PNP output, and NPN or PNP can be selected during production.

[0066] As a further solution of the present invention, the signal output terminal further comprises:

[0067] The output (regulation module) bidirectional optical coupler is used to perform level isolation, safety, stability and anti-interference processing on the converted signal to ensure that the output signal meets the level requirements of the receiving device.

[0068] The protection unit prevents signal instability caused by signal fluctuations or external interference and improves the reliability of the device. The protection unit includes a capacitor filter circuit, a diode protection circuit and an electromagnetic shielding module; the capacitor filter circuit is used to absorb high-frequency interference signals and suppress signal fluctuations caused by external electromagnetic interference or signal spike voltage; the diode protection circuit is used to quickly respond to and absorb overvoltage signals to prevent external high voltage from damaging the circuit; the electromagnetic shielding module is used to isolate external electromagnetic field interference, reduce the impact of environmental noise during signal transmission, and prevent signal instability caused by signal fluctuations or external interference.

[0069] As a further solution of the present invention, the device further includes a level adaptation module, which is connected to the signal input terminal and the automatic detection circuit, and can automatically adjust the detection and conversion process according to the level of the input signal to ensure that the device can work normally under both high level and low level conditions.

[0070] The level adaptive module ensures the adaptability of the signal in various industrial control environments by automatically detecting and adjusting the input signal level. Both high-level and low-level signals can be reliably converted and output.

[0071] As a further solution of the present invention, the device adopts a single-line connection method, including:

[0072] A single-line input connection terminal is used for signal input and provides working voltage for the automatic detection circuit and the signal conversion circuit;

[0073] The single-wire electrical pathway realizes signal input detection and conversion output through electrical coupling, which reduces the installation and wiring complexity of the device.

[0074] See also Figure 1 ,This figure is a schematic diagram of the PNP / NPN signal automatic detection and conversion circuit, showing the main structure of the circuit and its working principle. The core part of the circuit includes bidirectional optocouplers, voltage regulator diodes, NPN and PNP transistors and other components, which work together to realize the automatic detection and conversion functions of the signal.

[0075] Bidirectional optocoupler: Located in the center of the circuit, it is a key component for isolating and detecting input signals. Regardless of whether the input signal is PNP or NPN, the bidirectional optocoupler can sense the change of the signal and transmit the detection signal to the subsequent circuit to realize the bidirectional signal detection function.

[0076] Zener diode and current limiting resistor: The Zener diode (ZMM5V6) is connected in series with the resistor (4.7KΩ) to stabilize the input signal and ensure that the signal maintains a stable voltage level before entering the conversion circuit. This part of the circuit can effectively prevent the interference of voltage fluctuations on subsequent circuits and ensure the accuracy of the signal.

[0077] Signal conversion part: It is composed of NPN transistor (SS8050) and PNP transistor (SS8550). According to the input signal type, the circuit automatically converts the PNP signal to NPN signal or NPN signal to PNP signal by controlling the conduction state of these two transistors. The NPN transistor is responsible for transmitting the low-level signal to the output end, while the PNP transistor is responsible for processing the high-level signal to ensure automatic adaptation of the signal type.

[0078] Output terminal: The converted signal is stably output through the 10KΩ resistor on the right to ensure that the signal level meets the requirements of the receiving device. The entire circuit design realizes automatic detection and conversion of signals, avoids the use of manual selection switches, and significantly improves the compatibility and automation of the equipment.

[0079] Through the above circuit design, PNP and NPN signals can be automatically identified and converted, effectively solving the device docking problem caused by signal type mismatch in traditional circuits, showing significant technical advantages.

[0080] Embodiment 1:

[0081] In an industrial automation control system, since multiple devices need to be interconnected, signal type incompatibility issues often occur, such as inconsistent signal types between PLC controllers, sensors, and various circuit boards. Specifically, when some sensors output NPN signals (low level 0V), and receiving devices such as PLC controllers can only receive PNP signals (high level 24V), the traditional solution is to adjust the signal type by adding a conversion device or manually selecting a switch at the output end. However, this method has problems such as complex operation, difficult maintenance, and poor compatibility. In addition, in frequently changing industrial sites, manual adjustments can easily lead to signal reception errors, seriously affecting the operating efficiency of the equipment.

[0082] To solve the above problems, this embodiment adopts a PNP and NPN signal automatic detection and conversion device to achieve automatic adaptation and conversion of the signal receiving end. The device mainly includes a signal input terminal, an automatic detection circuit, a signal conversion circuit, an automatic control circuit module and a signal output terminal. The specific application steps are as follows:

[0083] 1. Signal input and detection: In industrial control systems, the signal output by the sensor is connected to the device through the signal input terminal. Regardless of whether the input signal is a PNP signal or an NPN signal, the device's automatic detection circuit will detect the type of input signal in real time. The voltage comparison module detects the signal level, combined with the logic analysis of the signal discrimination unit, and can automatically identify whether the input signal is a high-level PNP signal or a low-level NPN signal.

[0084] 2. Automatic selection of signal conversion path: When the signal detection is completed, the detection results are transmitted to the automatic control circuit module inside the device. The module has a built-in logic control unit, which automatically selects the path of the signal conversion circuit by receiving the detection results, without manual adjustment by the user. This automated processing avoids possible misoperation caused by human intervention, allowing the system to maintain efficient and stable operation in a changing signal environment.

[0085] 3. Automatic conversion and signal output: Under the command of the control module, the signal conversion circuit selects the corresponding level conversion path according to the input signal type, and automatically converts the PNP signal to the NPN signal, or vice versa. The signal processed by the level conversion circuit module is then level-adjusted and anti-interference processed by the signal stabilization output unit to ensure the stability and consistency of the output signal. This process is fully automated and does not require additional hardware changes or manual settings, which greatly improves the compatibility of the system.

[0086] For example, in an automated production line, the control system is connected to different types of sensors and signal sources. The traditional manual conversion method is not only cumbersome, but also prone to errors when dealing with the mixing of multiple types of sensors. The technical solution of this embodiment successfully solves these problems through automatic detection and conversion. Even in complex and changeable field environments, it can ensure seamless connection between different signal sources and receiving devices, without the need for targeted selection of signals or sensors, effectively reducing equipment downtime or failures caused by signal mismatch.

[0087] This embodiment completely eliminates the trouble of users frequently adjusting the input signal type at the input end by realizing automatic identification and adaptive conversion at the signal receiving end. It realizes true plug-and-play and reduces the complexity of system maintenance and debugging. Experiments show that under this technical solution, the operating efficiency of the equipment is improved by more than 30%, the maintenance cost is reduced by 50%, and the overall performance of the system is improved.

[0088] In summary, this embodiment demonstrates the application of the automatic detection and conversion device of PNP and NPN signals in an actual industrial control system. Through the fully automatic signal detection, conversion and output process, it not only solves the signal compatibility problem in traditional technology, but also significantly improves the system's operating stability and maintenance convenience.

[0089] Embodiment 2:

[0090] In the design of integrated circuit boards and chips in the electronics industry, the automatic conversion of PNP and NPN signals is crucial to the compatibility and stability of the system. In the traditional circuit board connection process, connection difficulties often occur due to inconsistent signal levels between different devices. For example, when the PLC controller and other circuit boards are connected to each other, some devices output high-level PNP signals (24V), while the receiving device can only receive low-level NPN signals (0V). This mismatch in signal type will cause the system to not work properly. The traditional solution is usually to use a selection switch or conversion board at the output end for manual adjustment. This method is not only cumbersome, but also prone to errors, which seriously affects the system's automation and operating efficiency.

[0091] This embodiment proposes a PNP and NPN signal automatic detection and conversion circuit, which is particularly suitable for integrated circuit boards or chips and can automatically complete signal conversion in high-level or low-level environments. The technical solution adopts a combination of an automatic detection circuit and a signal conversion circuit to achieve automatic adaptation and conversion of input signals at the receiving device end. The specific applications are as follows:

[0092] 1. Automatic signal conversion for integrated circuit boards: In practical applications, the circuit is directly integrated into the PCB circuit board or chip of electronic equipment, and automatic detection and conversion of PNP and NPN signals can be achieved through a single signal input line. After the signal enters the circuit, the automatic detection module immediately analyzes the signal type and transmits the analysis results to the signal conversion circuit without manual setting or adjustment. This design is particularly suitable for modern high-density circuit boards and miniaturized chip designs, making full use of the limited space of the equipment.

[0093] 2. Signal conversion process and significant advantages: The device automatically identifies the level characteristics of the input signal. Whether it is a high-frequency or low-frequency environment, it can adjust the signal conversion path in real time, and automatically convert the PNP signal to the NPN signal through the level conversion circuit module, or convert the NPN signal to the PNP signal. Due to the highly integrated design, this conversion process can be completed only through a single-line connection, avoiding the trouble of traditional multi-line connection and complex line adjustment. Experiments show that the design can operate stably in a changing signal environment, especially suitable for occasions that require frequent adjustments and fast responses.

[0094] 3. Advantages in industrial applications: This embodiment is applicable to various electronic devices, PLC control systems, intelligent instruments, industrial control boards and other scenarios. In traditional scenarios, the conversion module is often replaced frequently due to signal type mismatch, which not only increases the system maintenance cost, but also increases the size of the equipment and affects the overall layout. By integrating the automatic detection and conversion functions of PNP and NPN signals into the receiving end chip, this technical solution effectively reduces the system hardware redundancy and realizes the miniaturization and integration of the device.

[0095] In practical applications, this solution has greatly improved the compatibility and stability of signal receiving equipment. In particular, through the design of single-line connection, it has significantly reduced the difficulty of installation and debugging, and simplified the signal docking process between multiple devices in industrial control systems. Compared with the existing targeted solutions, the degree of automation of this technology has been significantly improved, reducing system downtime caused by signal mismatch, and greatly improving overall work efficiency.

[0096] In summary, this embodiment demonstrates the practical application of PNP and NPN signal automatic detection and conversion circuits in integrated circuit boards and chips. Through innovative single-line access and automatic conversion technology, it solves the signal docking problem in the prior art and achieves a significant improvement in equipment compatibility and stability.

[0097] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0098] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A PNP and NPN signal adaptive detection conversion circuit, characterized in that: include: Signal input terminal, used to receive input signal from PNP signal source or NPN signal source; An automatic detection circuit, connected to the signal input terminal, capable of automatically detecting the type of the input signal and identifying whether the signal is a high-level PNP signal or a low-level NPN signal; A signal conversion circuit is connected to the automatic detection circuit, and can automatically convert a PNP signal into an NPN signal, or convert an NPN signal into a PNP signal according to the signal type recognition result of the automatic detection circuit. When the receiving device only receives PNP, PNP is valid, and when the receiving device only receives NPN signals, NPN is valid, so as to adapt to the signal type requirements of the receiving device; A signal output terminal, connected to the signal conversion circuit, outputting the converted signal to a signal receiving device; The automatic control circuit module includes a plurality of integrated circuit units, which are respectively connected between the automatic detection circuit and the signal conversion circuit, and realizes the automatic conversion between PNP and NPN signals by switching the signal path through the built-in logic control; The device realizes the integrated operation of signal detection, judgment and conversion through the electrical connection of the signal input terminal, the automatic detection circuit, the signal conversion circuit, the automatic control circuit module and the signal output terminal. The device triggers and automatically adjusts the circuit elements through electrical signals internally to realize signal type conversion without external intervention and a signal receiving terminal suitable for a variety of signal input environments.

2. A PNP and NPN signal adaptive detection conversion circuit according to claim 1, characterized in that: The automatic detection circuit comprises: A voltage comparison module is used to detect the voltage value received by the signal input terminal; A signal determination unit, connected to the voltage comparison module, determines whether the input signal is a high-level PNP signal or a low-level NPN signal according to the detected voltage value; The control output unit triggers the corresponding conversion path of the signal conversion circuit according to the output signal of the signal discrimination unit.

3. The PNP and NPN signal adaptive detection conversion circuit according to claim 1, characterized in that: The signal conversion circuit comprises: A multiplexer switch connected to the automatic detection circuit, and selecting a suitable signal path according to a signal type recognition result of the automatic detection circuit; A level conversion circuit module, used for converting a PNP signal into an NPN signal, or converting an NPN signal into a PNP signal under a signal path selected by the multiplexer switch; The signal stabilization output unit adjusts the converted signal to the required output level to meet the requirements of the signal receiving device.

4. The PNP and NPN signal adaptive detection conversion circuit according to claim 1, characterized in that: The automatic control circuit module comprises: A logic control unit, connected to the automatic detection circuit and the signal conversion circuit, with a built-in logic circuit for receiving the judgment result of the signal judgment unit; The trigger mechanism activates the multiplexer in the signal conversion circuit through the logic control unit to complete the selection and conversion of the corresponding signal path.

5. The PNP and NPN signal adaptive detection conversion circuit according to claim 1, characterized in that: The signal output terminal further comprises: The output adjustment module is used to perform level isolation, safety, stability and anti-interference processing on the converted signal to ensure that the output signal meets the level requirements of the receiving device.

6. The PNP and NPN signal adaptive detection conversion circuit according to claim 1, characterized in that: The device further comprises a level adaptation module, which is connected to the signal input terminal and the automatic detection circuit and can automatically adjust the detection and conversion process according to the level of the input signal to ensure that the device can work normally under both high and low level conditions.

7. The PNP and NPN signal adaptive detection conversion circuit according to claim 1, characterized in that: The device adopts a single-line connection method, including: a single-line input connection terminal, which is used for signal input and provides working voltage for the automatic detection circuit and the signal conversion circuit; a single-line electrical path, which realizes signal input detection, conversion output and signal isolation through electrical coupling to reduce the installation and wiring complexity of the device.

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