Dual anti-false-tripping circuit of intelligent molded case controller

Abstract

The utility model relates to a dual anti-false tripping circuit of an intelligent molded case controller, and relates to the field of circuit breaker equipment, the circuit comprises a first comparison circuit, a second comparison circuit and a magnetic flux tripping circuit; the first comparison circuit is connected with the second comparison circuit, and the second comparison circuit is electrically connected with the magnetic flux tripping circuit; the magnetic flux voltage is monitored through the first comparison circuit, and the second comparison circuit is combined with the output of the first comparison circuit and the voltage of the MCU, so that whether the magnetic flux tripping circuit needs to be controlled to turn on or turn off the magnetic flux transformer is reliably judged, misoperation caused by abnormal working voltage is prevented, and the circuit reliability is improved.

Description

Technical Field

[0001] The present application relates to the field of circuit breaker equipment, and in particular to a double anti-mistripping circuit of an intelligent molded case controller. Background Art

[0002] With the popularity of electronic molded case circuit breakers, because they use single-chip microcomputers as components for calculating and controlling tripping, the operation of single-chip microcomputers depends on the stability of the working power supply. However, due to the size and application scenario limitations of electronic molded case circuit breakers, as well as the use of new inductive power supply technology, the working power supply of electronic molded case circuit breakers can work normally without an additional external power supply. Since the principle of inductive power supply is to sense the current of the main circuit of the molded case circuit breaker through an iron core transformer and control the working voltage formed. Its energy is unstable and changes with the load. At the same time, the power consumption of the electronic controller is required to be as stable as possible without large fluctuations. However, in actual use, when the load current fluctuates near and below the threshold where the energy of the inductive power supply can meet the use of the electronic controller, the working power supply at this time is extremely unstable. It is very likely that the comparison power supply of the single-chip microcomputer is low and there will be a false trip, or the working voltage of the tripping circuit is insufficient, resulting in problems such as failure to trip. Utility Model Content

[0003] The present application provides a dual anti-misoperation tripping circuit of an intelligent plastic case controller, which monitors the flux voltage through a first comparison circuit, and the second comparison circuit combines the output of the first comparison circuit and the MCU voltage, so as to reliably judge whether it is necessary to control the flux tripping circuit to turn on or off the flux transformer, thereby preventing misoperation caused by abnormal working voltage and improving circuit reliability.

[0004] The present application provides a dual anti-mistake tripping circuit of an intelligent molded case controller, which adopts the following technical solution: the circuit includes a first comparison circuit, a second comparison circuit and a magnetic flux tripping circuit; the first comparison circuit is connected to the second comparison circuit, and the second comparison circuit is electrically connected to the magnetic flux tripping circuit;

[0005] The first comparison circuit is used to monitor whether the flux voltage of the flux working power supply reaches a preset flux working voltage, and output a first level signal to the second comparison circuit according to the flux voltage and the preset flux working voltage;

[0006] When the magnetic flux voltage is less than the preset magnetic flux working voltage, a first low level signal is output to the second comparison circuit; when the magnetic flux voltage is greater than the preset magnetic flux working voltage, a first high level signal is output to the second comparison circuit;

[0007] The second comparison circuit is used to monitor the MCU voltage of the MCU working power supply, and output a second level signal to the flux tripping circuit according to the first level signal and the MCU voltage;

[0008] The flux tripping circuit is used for controlling the flux tripping according to the second level signal after receiving the second level signal.

[0009] By adopting the above technical solution, the first comparison circuit monitors whether the flux voltage of the flux working power supply reaches the preset flux working voltage, and outputs the first level signal to the second comparison circuit according to the flux voltage and the preset flux working voltage. When the flux voltage is less than the preset flux working voltage, the first low level signal is output to the second comparison circuit; when the flux voltage is greater than the preset flux working voltage, the first high level signal is output to the second comparison circuit. This step can timely and accurately reflect the state of the flux voltage. Next, the second comparison circuit monitors the MCU voltage of the MCU working power supply, and outputs the second level signal to the flux tripping circuit according to the first level signal and the MCU voltage. In this way, the state of the flux voltage and the MCU voltage is comprehensively considered, and the working state of the system is more comprehensively evaluated. Finally, after the flux tripping circuit receives the second level signal, the flux tripping is controlled according to the second level signal. That is to say, only when the flux voltage and the MCU voltage are in a normal working state, the flux is allowed to be normally turned on and off; once any voltage is abnormal, the flux tripping will be controlled to prevent misoperation.

[0010] This application uses a two-stage cascade comparison circuit to monitor the flux voltage and MCU voltage respectively, and organically combines the states of the two to control the flux tripping circuit. This dual monitoring and dual judgment mechanism greatly improves the ability to detect abnormal working conditions, thereby effectively preventing problems such as false tripping or failure to trip due to voltage abnormalities, and ensuring the reliability and stability of the entire system.

[0011] Optionally, the first comparison circuit is further configured to output the first level signal as a first low level signal when the magnetic flux voltage is less than the preset magnetic flux working voltage;

[0012] When the flux voltage is greater than the preset flux operating voltage, the output first level signal is a first high level signal.

[0013] By adopting the above technical solution, the first comparison circuit is also used to output a first low level signal when the flux voltage is less than the preset flux working voltage; and output a first high level signal when the flux voltage is greater than the preset flux working voltage.

[0014] This design enables the first comparison circuit to not only detect whether the magnetic flux voltage reaches the preset working voltage, but also output different level signals according to the level of the magnetic flux voltage. This dual-state output design has the following benefits and technical effects:

[0015] First, by presetting a threshold value of the flux working voltage, the first comparison circuit can clearly divide the flux voltage into two conditions: normal state and abnormal state. When the flux voltage is lower than the threshold, a low-level signal is output, indicating that the flux voltage is in an abnormally low voltage state; conversely, a high-level signal is output, indicating that the flux voltage is in a normal working state. This dual-state output is simple and intuitive, providing a clear basis for subsequent judgment. Secondly, the high and low levels of the first level signal itself have judgment significance and can be directly used for the control of subsequent circuits. For example, the second comparison circuit can directly make further judgments and controls based on the state of the first level signal in combination with the MCU voltage, without the need for additional logical judgments, thereby simplifying the circuit design and improving efficiency. Thirdly, the dual-state output design of the first comparison circuit is conducive to improving the accuracy and reliability of the comparison judgment. By converting the analog flux voltage into digital high and low level signals, the errors that may exist in the analog quantity comparison can be effectively avoided, thereby ensuring the accuracy of the output results and laying the foundation for the normal operation of the entire anti-mistake tripping circuit. In short, this dual-state output design of the first comparison circuit not only simplifies the circuit structure, but also improves the accuracy and reliability of the comparison judgment, provides a strong guarantee for the normal operation of the entire anti-false tripping circuit, and is an effective technical solution.

[0016] Optionally, the second comparison circuit is further configured to output the second level signal as a second high level signal when the MCU voltage is greater than a preset MCU operating voltage and the first level signal is a first high level signal;

[0017] When the MCU voltage is greater than the preset MCU operating voltage and the first level signal is a first low level signal, the output second level signal is a second low level signal.

[0018] By adopting the above technical solution, the second comparison circuit is also used to output a second high-level signal when the MCU voltage is greater than the preset MCU operating voltage and the first level signal number is a first high-level signal number; when the MCU voltage is greater than the preset MCU operating voltage and the first level signal number is a first low-level signal number, the second low-level signal number is output. This design enables the second comparison circuit to not only monitor the MCU operating voltage, but also comprehensively judge the working state of the entire system based on the first level signal (reflecting the flux voltage state) output by the first comparison circuit, thereby outputting a reasonable second level signal to control the subsequent flux tripping action.

[0019] By presetting the operating voltage thresholds of the MCU and the flux, the second comparison circuit can accurately determine whether the MCU voltage and the flux voltage are in normal working state. According to the combination of the MCU voltage and the first level signal, the second comparison circuit can comprehensively divide the system into four different working states: the MCU voltage is normal and the flux voltage is normal, the MCU voltage is normal but the flux voltage is abnormal, the MCU voltage is abnormal but the flux voltage is normal, and the MCU voltage is abnormal and the flux voltage is abnormal. Corresponding to these four states, the second comparison circuit outputs a high level or a low level second level signal respectively, which reflects the actual working condition of the system in detail and comprehensively.

[0020] Finally, after the flux trip circuit receives the second level signal, the flux is allowed to conduct normally only when the MCU and the flux voltage are in normal state (corresponding to the second high level signal); once any voltage is abnormal (corresponding to the second low level signal), the flux will be controlled to trip, thereby effectively preventing misoperation. Through this comprehensive judgment design of the second comparison circuit, combined with the output of the first comparison circuit and the detection of the MCU voltage, the working state of the entire system is comprehensively evaluated, and different second level signals are output accordingly, providing a reliable basis for the correct control of the subsequent flux trip circuit.

[0021] Optionally, the circuit further includes an LDO circuit;

[0022] The LDO circuit is electrically connected to the second comparison circuit;

[0023] The LDO circuit is used to step down the system power supply to a preset reference voltage.

[0024] By adopting the above technical solution, the introduction of the LDO circuit provides a stable working voltage basis for the entire anti-false tripping circuit, especially for the key second comparison circuit, the LDO circuit can ensure its working reliability to the greatest extent.

[0025] Optionally, the first comparison circuit includes a comparator U3B, a resistor R2, a resistor R4 and a diode D1;

[0026] One end of the resistor R2 is connected to the flux working power supply, the other end of the resistor R2 is connected to the fifth pin of the comparator U3B, one end of the resistor R4 is connected to the fifth pin of the comparator U3B, the other end of the resistor R4 is grounded, the sixth pin of the comparator U3B is connected to the reference power supply, the seventh pin of the comparator U3B is connected to the cathode of the diode D1; the anode of the diode D1 is connected to the second comparison circuit.

[0027] By adopting the above technical solution, by reasonably selecting circuit elements such as resistors, comparators, diodes, and making appropriate connection arrangements, the specific circuit design of the first comparison circuit can efficiently complete the monitoring and digital output of the magnetic flux voltage, providing a reliable basis for the normal operation of the subsequent circuit.

[0028] Optionally, the second comparison circuit includes a second comparison comparator U3A, a resistor R10 and a resistor R11;

[0029] The third pin of the second comparator U3A is connected to the first comparison circuit, the second pin of the second comparator U3A is connected to the LDO circuit, and the first pin of the second comparator U3A is connected to the flux tripping circuit.

[0030] By adopting the above technical solution, the design of accurately outputting the second level signal according to the combination of the two inputs can reflect the real working state of the system to the maximum extent. After receiving different second level signals, the flux tripping circuit can accurately perform the corresponding flux tripping control action, thereby effectively preventing the occurrence of misoperation.

[0031] Optionally, the flux tripping circuit includes an NMOS tube Q1A, a resistor R6, a resistor R7, a diode D2 and a flux converter;

[0032] One end of the resistor R6 is connected to the second comparison circuit, the other end of the resistor R6 is connected to the second pin of the NMOS tube Q1A, one end of the resistor R7 is connected to the first pin of the NMOS tube Q1A, and the other end of the resistor R7 is grounded; the first pin of the NMOS tube Q1A is grounded, the eighth pin of the NMOS tube Q1A is connected to the negative pole G of the coil of the magnetic flux converter, and the seventh pin of the NMOS tube Q1A is connected to the negative pole G of the coil of the magnetic flux converter; the positive pole Y of the coil of the magnetic flux converter is connected to the magnetic flux working power supply; the negative pole of the diode D2 is connected to the positive pole Y of the coil of the magnetic flux converter, and the positive pole of the diode D2 is connected to the negative pole G of the coil of the magnetic flux converter.

[0033] By adopting the above technical solution, first, one end of the resistor R6 is connected to the second comparison circuit, and can directly receive the second level signal. When the second level signal is high, the NMOS tube Q1A is correctly driven to turn on; when it is low, the NMOS tube Q1A is turned off.

[0034] Secondly, the drain of NMOS tube Q1A is connected to the negative pole G of the flux transformer coil, and the source is grounded, forming a switch circuit. When the NMOS tube is turned on, the negative pole G of the coil is grounded, forming a path powered by the flux working power supply, passing through the positive pole Y of the coil and the negative pole G of the coil, and the transformer coil can work normally.

[0035] On the contrary, when the NMOS tube is turned off, the negative pole G of the coil is suspended, the path is interrupted, and the transformer cannot work normally. This realizes the on and off control of the flux transformer by using the NMOS tube.

[0036] Again, the introduction of diode D2 is to prevent the danger of overvoltage after the transformer is disconnected. When the transformer is disconnected, the positive and negative poles of the transformer will generate high voltage. At this time, diode D2 can be turned on and put the high voltage to the ground line, playing an overvoltage protection role.

[0037] Finally, the function of resistor R7 is current limiting protection. When the NMOS tube is turned on, R7 can limit the excessive current flowing through to prevent damage to the NMOS tube.

[0038] In summary, the structural design of the flux tripping circuit fully considers the safety and reliability of the circuit. It can not only accurately execute the control instructions of the second comparison circuit, but also has overvoltage and overcurrent protection measures, ensuring that the flux transformer can be normally and safely turned on and off under any working conditions.

[0039] Optionally, the LDO circuit includes a linear voltage regulator U4, a resistor R8 and a resistor R9;

[0040] The first pin of the linear voltage regulator U4 is connected to the system power supply, the second pin of the linear voltage regulator U4 is grounded, and the fifth pin of the linear voltage regulator U4 is connected to the second comparison circuit; one end of the resistor R8 is connected to the first pin of the linear voltage regulator U4, and the other end of the resistor R8 is connected to the third pin of the linear voltage regulator U4; one end of the resistor R9 is connected to the third pin of the linear voltage regulator U4, and the other end of the resistor R9 is grounded.

[0041] By adopting the above technical solution, the linear voltage regulator U4 is the core component of the LDO circuit, which has the function of accurately adjusting the input voltage to the required output voltage. By connecting to the system power supply, even if the system power supply fluctuates, the regulator U4 can adjust it to a fixed reference voltage output.

[0042] Secondly, resistors R8 and R9 form a feedback voltage divider network, which is connected to the third pin of the regulator U4. Through this feedback network, the regulator can detect the actual output voltage and automatically adjust the internal working mode to keep the output voltage accurately at the set value of the required reference voltage.

[0043] Thirdly, the output of the LDO circuit is directly connected to the reference voltage terminal of the second comparison circuit, which can provide a clean and stable operating voltage for the second comparison circuit. It is with the support of this regulated power supply that the second comparison circuit can accurately judge the state of the MCU voltage and the flux voltage under any circumstances, thereby correctly outputting the second level signal for controlling the flux tripping.

[0044] Finally, the LDO circuit adopts a linear regulation working mode, which has good anti-ripple capability and low noise characteristics. The output reference voltage is pure and smooth, providing a high-quality working environment for the second comparison circuit, avoiding errors introduced by voltage fluctuations or strays, and further improving the reliability of the entire anti-false tripping circuit.

[0045] In summary, the present application includes at least one of the following beneficial technical effects:

[0046] This application uses a two-stage cascade comparison circuit to monitor the flux voltage and MCU voltage respectively, and organically combines the states of the two to control the flux tripping circuit. This dual monitoring and dual judgment mechanism greatly improves the ability to detect abnormal working conditions, thereby effectively preventing problems such as false tripping or failure to trip due to voltage abnormalities, and ensuring the reliability and stability of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a structural schematic diagram of a double anti-mistake tripping circuit of an intelligent plastic case controller provided in an embodiment of the present application;

[0048] Figure 2 It is a circuit diagram of a double anti-mistake tripping circuit of an intelligent plastic case controller provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0050] The utility model discloses a double anti-mistake tripping circuit of an intelligent plastic shell controller to solve the problem that the bus voltage is not processed in time when the voltage in the existing photovoltaic area fluctuates greatly.

[0051] See also Figure 1 , a schematic diagram of the structure of a dual anti-mistake tripping circuit of an intelligent plastic case controller disclosed in an embodiment of the utility model, the circuit of the present application comprises a first comparison circuit, a second comparison circuit and a magnetic flux tripping circuit; the first comparison circuit is connected to the second comparison circuit, and the second comparison circuit is electrically connected to the magnetic flux tripping circuit;

[0052] The first comparison circuit is used to monitor whether the flux voltage of the flux working power supply reaches a preset flux working voltage, and output a first level signal to the second comparison circuit according to the flux voltage and the preset flux working voltage;

[0053] When the magnetic flux voltage is less than the preset magnetic flux working voltage, a first low level signal is output to the second comparison circuit; when the magnetic flux voltage is greater than the preset magnetic flux working voltage, a first high level signal is output to the second comparison circuit;

[0054] The second comparison circuit is used to monitor the MCU voltage of the MCU working power supply, and output a second level signal to the flux tripping circuit according to the first level signal and the MCU voltage;

[0055] The flux tripping circuit is used for controlling the flux tripping according to the second level signal after receiving the second level signal.

[0056] The first comparison circuit is also used for outputting the first level signal as a first low level signal when the magnetic flux voltage is less than the preset magnetic flux working voltage;

[0057] When the flux voltage is greater than the preset flux operating voltage, the output first level signal is a first high level signal.

[0058] In another achievable implementation, the circuit further includes an LDO circuit;

[0059] The LDO circuit is electrically connected to the second comparison circuit;

[0060] The LDO circuit is used to step down the system power supply to a preset reference voltage.

[0061] In one embodiment, the second comparison circuit is further configured to output the second level signal as a second high level signal when the MCU voltage is greater than a preset MCU operating voltage and the first level signal is a first high level signal;

[0062] When the MCU voltage is greater than the preset MCU operating voltage and the first level signal is a first low level signal, the output second level signal is a second low level signal.

[0063] Specifically, when the MCU voltage is greater than the preset MCU operating voltage and the first level signal number is a first high level signal number, the second comparison circuit outputs a second high level signal; when the MCU voltage is greater than the preset MCU operating voltage and the first level signal number is a first low level signal number, the second comparison circuit outputs a second low level signal.

[0064] This design can realize the comprehensive judgment of the two key parameters of MCU voltage and flux voltage, and output the corresponding control signal. Specifically, the second comparison circuit contains a second comparator U3A. By inputting the MCU voltage and the reference level of the preset MCU working voltage into the two ports of the comparator, it can be judged whether the MCU voltage is in a normal working state. At the same time, the first comparison circuit has judged the state of the flux voltage and reflected the result through the first level signal, which is also input to the second comparator U3A.

[0065] Therefore, the input end of the second comparator U3A integrates the state information of the MCU voltage and the flux voltage. By judging the level combination of these two inputs, the second comparator U3A can output the corresponding second level signal. When the MCU voltage is normal and the flux voltage is normal, a high-level second high-level signal is output; when the MCU voltage is normal but the flux voltage is abnormal or the MCU voltage is abnormal, a low-level second low-level signal is output.

[0066] This dual judgment design logic can reflect the real working state of the entire circuit system to the greatest extent. Since both the magnetic flux and the MCU voltage are key factors for the normal operation of the system, the magnetic flux should be allowed to remain on only when both are at normal levels; once an abnormality occurs at either end, the magnetic flux should be cut off immediately to prevent misoperation.

[0067] After the subsequent flux tripping circuit receives the second level signal output by the second comparison circuit, when it receives the second high level signal, it keeps the flux on; when it receives the second low level signal, it immediately controls the NMOS tube Q1A to be turned off, cutting off the power supply path of the flux transformer, thereby achieving safe and reliable flux tripping.

[0068] In short, this dual judgment function design of the second comparison circuit accurately detects the state combination of MCU voltage and flux voltage, and outputs a second level signal reflecting the actual working state of the system, which ensures the correct operation of the entire anti-false tripping circuit.

[0069] In one embodiment, the second comparison circuit is further configured to output the second level signal as a second high level signal when the MCU voltage is greater than a preset MCU operating voltage and the first level signal is a first high level signal;

[0070] When the MCU voltage is greater than the preset MCU operating voltage and the first level signal is a first low level signal, the output second level signal is a second low level signal.

[0071] Specifically, the second comparison circuit is designed to achieve a comprehensive judgment of the two key parameters of the MCU voltage and the flux voltage, and output a corresponding second level signal according to the judgment result, thereby providing a reliable control basis for the correct operation of the subsequent flux tripping circuit.

[0072] Specifically, the second comparator U3A inside the second comparison circuit, on the one hand, can determine whether the MCU voltage is in a normal working state by inputting the MCU voltage and the preset MCU working voltage reference value into its two ports; on the other hand, the first comparison circuit has determined the state of the flux voltage and reflected it through the first level signal, which serves as the other input terminal of the second comparator U3A. Therefore, the second comparator U3A combines the two key state information of the MCU voltage and the flux voltage.

[0073] Subsequently, the second comparator U3A judges the level combination of the two input terminals. When the MCU voltage is greater than the preset MCU operating voltage, and the first level signal number is the first high level signal number, it means that the MCU voltage is normal and the magnetic flux voltage is normal, and the second comparator U3A outputs a second high level signal; when the MCU voltage is greater than the preset MCU operating voltage, but the first level signal number is the first low level signal number, it means that although the MCU voltage is normal, the magnetic flux voltage is abnormal, and the second comparator U3A outputs a second low level signal; if the MCU voltage is lower than the operating voltage, regardless of the state of the magnetic flux voltage, the second comparator U3A outputs a second low level signal. The reason for designing this dual judgment logic is that both the magnetic flux and the MCU voltage are key factors for the normal operation of the system. Only when both are at normal levels can the entire system be considered safe and the magnetic flux should be allowed to continue to be turned on; once an abnormality occurs at any end, the magnetic flux should be cut off immediately to prevent accidental misoperation due to maintaining the passage.

[0074] Therefore, after the subsequent flux tripping circuit receives the second level signal output by the second comparison circuit, when it receives the second high level signal, it controls the flux to remain on; when it receives the second low level signal, it immediately controls the NMOS tube Q1A to be turned off, cutting off the power supply path of the flux transformer, thereby achieving safe and reliable flux tripping.

[0075] Through the dual judgment design of the second comparison circuit, the actual working status of the entire circuit system can be reflected to the maximum extent, and it can be accurately judged when the magnetic flux should be allowed to continue to conduct and when the magnetic flux should be cut off immediately, thereby fundamentally avoiding the occurrence of misoperation and ensuring the efficient and stable operation of the entire anti-mistripping circuit, with significant technical effects.

[0076] See also Figure 2 , the first comparison circuit includes a comparator U3B, a resistor R2, a resistor R4 and a diode D1;

[0077] One end of the resistor R2 is connected to the flux working power supply, the other end of the resistor R2 is connected to the fifth pin of the comparator U3B, one end of the resistor R4 is connected to the fifth pin of the comparator U3B, the other end of the resistor R4 is grounded, the sixth pin of the comparator U3B is connected to the reference power supply, the seventh pin of the comparator U3B is connected to the cathode of the diode D1; the anode of the diode D1 is connected to the second comparison circuit.

[0078] Specifically, the first comparison circuit includes a comparator U3B, a resistor R2, a resistor R4 and a diode D1, and its specific structure is connected as follows:

[0079] One end of resistor R2 is connected to the flux working power supply, and the other end is connected to the fifth pin of comparator U3B; one end of resistor R4 is also connected to the fifth pin of comparator U3B, and the other end is grounded. The sixth pin of comparator U3B is connected to the reference power supply, and the seventh pin is connected to the cathode of diode D1. The anode of diode D1 is connected to the second comparison circuit. The purpose of this circuit structure design is to realize the detection and digital output of the flux working voltage, thereby reflecting the working state of the flux voltage. Specifically:

[0080] First, resistors R2 and R4 form a piezoresistive voltage divider network, which divides the voltage from the flux working power supply and inputs it to the positive end of the comparator U3B. Since the level of the flux working voltage reflects the actual state of the flux voltage, the simulated flux voltage signal can be converted into a corresponding voltage divider value through the voltage divider network. Secondly, the reverse end of the comparator U3B is connected to a preset reference voltage. The comparator compares the voltage divider value input at the positive end with the reference voltage, and outputs a high level when the voltage divider value is higher than the reference voltage, and outputs a low level otherwise. This digital high and low level output achieves the purpose of converting the simulated flux voltage signal into a digital signal. Again, the output end of the comparator U3B is connected to the second comparison circuit through a diode D1. The diode D1 plays the role of unidirectional conduction and isolation and anti-feedback, ensuring that the signal is reliably transmitted to the second comparison circuit. Finally, by reasonably setting the voltage divider ratio of resistors R2 and R4 and the selection of the reference voltage, the output high and low levels of the comparator U3B can accurately correspond to the normal or abnormal state of the flux voltage.

[0081] It should be noted that TRIP_PWR is the flux working power supply, VCC2 is the system power supply, and TRIP_REF is the reference power supply.

[0082] See also Figure 2 , the second comparison circuit includes a second comparator U3A, a resistor R10 and a resistor R11;

[0083] The third pin of the second comparator U3A is connected to the first comparison circuit, the second pin of the second comparator U3A is connected to the LDO circuit, and the first pin of the second comparator U3A is connected to the flux tripping circuit.

[0084] Specifically, the second comparison circuit includes a second comparator U3A, resistors R10 and R11, and the connection method thereof is as follows: the third pin of the second comparator U3A is connected to the first comparison circuit, the second pin is connected to the LDO circuit, and the first pin is connected to the flux tripping circuit.

[0085] The purpose of this structural layout is to judge the overall working state of the system by combining the two inputs of the first comparison circuit and the MCU tripping signal through the second comparator U3A, and output a corresponding control signal according to the judgment result, so as to achieve precise control of the flux tripping circuit.

[0086] Specifically, the third pin of the second comparator U3A receives the output signal from the first comparison circuit, which reflects whether the flux working power supply TRIP_PWR is in a normal state. When the TRIP_PWR voltage is normal, the first comparison circuit outputs a high level; when the voltage is abnormal, it outputs a low level. At the same time, the other input end of the second comparator U3A receives the trip signal TRIP_JUDGE generated by the MCU after judging the input current. When TRIP_JUDGE is high, it means that the MCU has issued a flux trip command; when it is low, it means that no trip command has been issued.

[0087] Therefore, the second comparator U3A integrates two key information: the flux working power supply status and the MCU tripping command. Through internal comparison and judgment, when the TRIP_PWR voltage is normal and the MCU issues a tripping command, the second comparator U3A outputs a high-level signal; otherwise, once the TRIP_PWR voltage is abnormal or the MCU does not issue a tripping command, it outputs a low-level signal.

[0088] The high and low level output signals are directly transmitted to the flux tripping circuit through the first pin of the second comparator U3A. When a high level signal is received, the flux tripping circuit controls the MOS tube Q1A to conduct to ensure the normal operation of the flux; when a low level signal is received, the MOS tube Q1A is immediately turned off, the power supply circuit of the flux is cut off, and the flux tripping action is performed.

[0089] On the other hand, the second pin of the second comparator U3A is connected to the LDO circuit U4, and a stable reference voltage TRIP_REF can be obtained from the LDO circuit to provide an accurate comparison reference level for the second comparator U3A, thereby ensuring the accuracy of the comparison judgment.

[0090] See also Figure 2 , the flux tripping circuit includes an NMOS tube Q1A, a resistor R6, a resistor R7, a diode D2 and a flux converter;

[0091] One end of the resistor R6 is connected to the second comparison circuit, the other end of the resistor R6 is connected to the second pin of the NMOS tube Q1A, one end of the resistor R7 is connected to the first pin of the NMOS tube Q1A, and the other end of the resistor R7 is grounded; the first pin of the NMOS tube Q1A is grounded, the eighth pin of the NMOS tube Q1A is connected to the negative pole G of the coil of the magnetic flux converter, and the seventh pin of the NMOS tube Q1A is connected to the negative pole G of the coil of the magnetic flux converter; the positive pole Y of the coil of the magnetic flux converter is connected to the magnetic flux working power supply; the negative pole of the diode D2 is connected to the positive pole Y of the coil of the magnetic flux converter, and the positive pole of the diode D2 is connected to the negative pole G of the coil of the magnetic flux converter.

[0092] Specifically, the flux tripping circuit includes an NMOS tube Q1A, resistors R6, R7, a diode D2 and a flux transformer, which are connected as follows: one end of the resistor R6 is connected to the second comparison circuit, and the other end is connected to the second pin of the NMOS tube Q1A; one end of the resistor R7 is connected to the first pin of the NMOS tube Q1A, and the other end is grounded; the third pin of the NMOS tube Q1A is grounded, and the eighth pin and the seventh pin are both connected to the negative pole G of the coil of the flux transformer; the positive pole Y of the coil of the flux transformer is connected to the flux working power supply TRIP_PWR; the cathode of the diode D2 is connected to the positive pole Y of the transformer coil, and the anode is connected to the negative pole G of the coil.

[0093] The purpose of this circuit structure layout is to accurately control the on or off state of the NMOS tube Q1A according to the output signal of the second comparison circuit, so as to cut off or restore the power supply circuit of the flux transformer, and then control the opening or conduction of the flux.

[0094] Specifically, the output signal of the second comparison circuit is transmitted to the second pin, i.e., the gate, of the NMOS transistor Q1A through the resistor R6. When the second comparison circuit outputs a high level, the NMOS transistor Q1A is correctly driven to turn on; otherwise, when the output is a low level, the NMOS transistor Q1A is turned off.

[0095] The drain of NMOS tube Q1A is connected to the negative pole G of the flux transformer coil, and the source is grounded, forming a power supply circuit for the flux transformer. When NMOS tube Q1A is turned on, the negative pole G of the coil is grounded, thus forming a path from the flux working power supply TRIP_PWR through the positive pole Y of the coil and the negative pole G of the coil. At this time, the transformer coil can work normally and the flux remains in the conducting state. Conversely, when NMOS tube Q1A is turned off, the negative pole G of the coil is suspended, the path is interrupted, the transformer cannot work normally, and the flux is forced to trip and shut down.

[0096] At the same time, the introduction of diode D2 is to prevent the danger of overvoltage after the flux transformer is disconnected. When the transformer is disconnected, the positive and negative poles of the coil will generate a very high back electromotive force voltage. At this time, diode D2 can be turned on and put the high voltage to the ground line, playing an overvoltage protection role and avoiding damage to circuit components.

[0097] In addition, the function of resistor R7 is current limiting protection. When the NMOS tube Q1A is turned on, R7 can limit the excessive current flowing through to prevent damage to the NMOS tube.

[0098] Through this design, the flux tripping circuit can accurately execute the control instructions of the second comparison circuit. When a high-level signal is received, the flux is kept normally on; when a low-level signal is received, the power supply circuit of the flux is immediately cut off, and the flux tripping is forced to be executed to avoid misoperation. While ensuring the reliability of the flux operation, the entire circuit also has overvoltage and overcurrent protection measures.

[0099] See also Figure 2 , in an achievable implementation, the LDO circuit includes a linear voltage regulator U4, a resistor R8 and a resistor R9;

[0100] The first pin of the linear voltage regulator U4 is connected to the system power supply, the second pin of the linear voltage regulator U4 is grounded, and the fifth pin of the linear voltage regulator U4 is connected to the second comparison circuit; one end of the resistor R8 is connected to the first pin of the linear voltage regulator U4, and the other end of the resistor R8 is connected to the third pin of the linear voltage regulator U4; one end of the resistor R9 is connected to the third pin of the linear voltage regulator U4, and the other end of the resistor R9 is grounded.

[0101] Specifically, the LDO circuit includes a linear voltage regulator U4, a resistor R8 and a resistor R9, which are connected as follows: a first pin of the linear voltage regulator U4 is connected to a system power supply VCC2, a second pin is grounded, and a fifth pin is connected to a second comparison circuit; one end of the resistor R8 is connected to the first pin of the regulator U4, and the other end is connected to the third pin; one end of the resistor R9 is connected to the third pin of the regulator U4, and the other end is grounded.

[0102] The purpose of designing this LDO circuit is to convert the unstable system power supply VCC2 into a stable DC reference voltage TRIP_REF and output it to the second comparison circuit, so as to provide a reliable operating voltage for the second comparison circuit and ensure its normal operation.

[0103] Specifically, the linear voltage regulator U4 is the core component of the LDO circuit, which has the function of accurately adjusting the input voltage to the required output voltage. By connecting the system power supply VCC2 to the first pin of the regulator U4, even if VCC2 fluctuates, the regulator U4 can adjust it to a fixed reference voltage TRIP_REF output.

[0104] Resistors R8 and R9 form a feedback voltage divider network connected to the third pin of regulator U4. Through this feedback network, the regulator can detect the actual output voltage and automatically adjust the internal operating mode to keep the output voltage accurately at the set value of the required TRIP_REF level.

[0105] The output end of the LDO circuit is directly connected to the second comparison circuit through the fifth pin of the regulator U4, which can provide a clean and stable reference voltage TRIP_REF for the second comparison circuit. It is with the support of this regulated power supply that the second comparison circuit can accurately compare the MCU trip signal TRIP_JUDGE and the output signal of the first comparison circuit under any circumstances, and correctly output the signal for controlling the magnetic flux trip.

[0106] In addition, the LDO circuit adopts a linear regulation working mode, has good anti-ripple capability and low noise characteristics, and the output TRIP_REF voltage is pure and smooth, providing a high-quality working environment for the second comparison circuit, avoiding errors introduced by voltage fluctuations or strays, and further improving the reliability and accuracy of the entire anti-false tripping circuit.

[0107] It should be noted that TRIP_REF is derived from VCC2 after being stepped down by U4's LDO. R8 and R9 are a voltage divider network used to control U4 to start or stop working.

[0108] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A double anti-mistake tripping circuit of an intelligent plastic case controller, characterized in that: The circuit includes a first comparison circuit, a second comparison circuit and a magnetic flux tripping circuit; the first comparison circuit is connected to the second comparison circuit, and the second comparison circuit is electrically connected to the magnetic flux tripping circuit; The first comparison circuit is used to monitor whether the flux voltage of the flux working power supply reaches a preset flux working voltage, and output a first level signal to the second comparison circuit according to the flux voltage and the preset flux working voltage; When the magnetic flux voltage is less than the preset magnetic flux working voltage, a first low level signal is output to the second comparison circuit; when the magnetic flux voltage is greater than the preset magnetic flux working voltage, a first high level signal is output to the second comparison circuit; The second comparison circuit is used to monitor the MCU voltage of the MCU working power supply, and output a second level signal to the flux tripping circuit according to the first level signal and the MCU voltage; The flux tripping circuit is used for controlling the flux tripping according to the second level signal after receiving the second level signal.

2. The circuit according to claim 1, characterized in that The first comparison circuit is also used for outputting the first level signal as a first low level signal when the magnetic flux voltage is less than the preset magnetic flux working voltage; When the flux voltage is greater than the preset flux operating voltage, the output first level signal is a first high level signal.

3. The circuit according to claim 1, characterized in that The second comparison circuit is further configured to output the second level signal as a second high level signal when the MCU voltage is greater than a preset MCU operating voltage and the first level signal is a first high level signal; When the MCU voltage is greater than the preset MCU operating voltage and the first level signal is a first low level signal, the output second level signal is a second low level signal.

4. The circuit according to claim 1, characterized in that the circuit further comprises an LDO circuit; The LDO circuit is electrically connected to the second comparison circuit; The LDO circuit is used to step down the system power supply to a preset reference voltage.

5. The circuit according to claim 1, characterized in that The first comparison circuit includes a comparator U3B, a resistor R2, a resistor R4 and a diode D1; One end of the resistor R2 is connected to the flux working power supply, the other end of the resistor R2 is connected to the fifth pin of the comparator U3B, one end of the resistor R4 is connected to the fifth pin of the comparator U3B, the other end of the resistor R4 is grounded, the sixth pin of the comparator U3B is connected to the reference power supply, the seventh pin of the comparator U3B is connected to the cathode of the diode D1; the anode of the diode D1 is connected to the second comparison circuit.

6. The circuit according to claim 4, characterized in that The second comparison circuit includes a second comparison comparator U3A, a resistor R10 and a resistor R11; The third pin of the second comparator U3A is connected to the first comparison circuit, the second pin of the second comparator U3A is connected to the LDO circuit, and the first pin of the second comparator U3A is connected to the flux tripping circuit.

7. The circuit according to claim 1, characterized in that The magnetic flux tripping circuit includes an NMOS tube Q1A, a resistor R6, a resistor R7, a diode D2 and a magnetic flux converter; One end of the resistor R6 is connected to the second comparison circuit, the other end of the resistor R6 is connected to the second pin of the NMOS tube Q1A, one end of the resistor R7 is connected to the first pin of the NMOS tube Q1A, and the other end of the resistor R7 is grounded; the first pin of the NMOS tube Q1A is grounded, the eighth pin of the NMOS tube Q1A is connected to the negative pole G of the coil of the magnetic flux converter, and the seventh pin of the NMOS tube Q1A is connected to the negative pole G of the coil of the magnetic flux converter; the positive pole Y of the coil of the magnetic flux converter is connected to the magnetic flux working power supply; the negative pole of the diode D2 is connected to the positive pole Y of the coil of the magnetic flux converter, and the positive pole of the diode D2 is connected to the negative pole G of the coil of the magnetic flux converter.

8. The circuit according to claim 4, characterized in that The LDO circuit includes a linear voltage regulator U4, a resistor R8 and a resistor R9; The first pin of the linear voltage regulator U4 is connected to the system power supply, the second pin of the linear voltage regulator U4 is grounded, and the fifth pin of the linear voltage regulator U4 is connected to the second comparison circuit; one end of the resistor R8 is connected to the first pin of the linear voltage regulator U4, and the other end of the resistor R8 is connected to the third pin of the linear voltage regulator U4; one end of the resistor R9 is connected to the third pin of the linear voltage regulator U4, and the other end of the resistor R9 is grounded.

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