Multifunctional direct-current electronic circuit breaker without mechanical contact

Abstract

The invention discloses a multifunctional direct current electronic circuit breaker without a mechanical contact, which belongs to the technical field of circuit breakers, and comprises an MCU (Microprogrammed Control Unit) main control circuit, an intelligent switch module circuit, a dial switch input circuit and a key input circuit, meanwhile, channel current, voltage and self temperature value are detected; the dial switch input circuit is used for integrating channel protection current and preventing false triggering; the key input circuit is used for opening, closing or resetting a corresponding channel through a mechanical button; and the MCU main control circuit is used for opening and closing a channel according to a protection current value set by the dial switch and a switch instruction input by the key, and judging the collected current and voltage values, so that overcurrent protection and overvoltage and undervoltage protection are realized, and temperature segmentation compensation is performed according to a temperature value. The circuit breaker has no mechanical contact, and has the functions of short-circuit protection, overcurrent protection and overvoltage and undervoltage protection.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and more particularly to a multifunctional direct current electronic circuit breaker without mechanical contacts. Background Art

[0002] As a key protection device in the power system, circuit breakers are widely used in residential, commercial and industrial fields, mainly to prevent circuit overload, short circuit and other electrical faults from damaging the power system or electrical equipment. Its basic working principle is to monitor the current change through the internal current sensing device (such as thermal bending piece and electromagnetic release), and automatically cut off the circuit when abnormal current is detected, so as to protect the circuit and its connected equipment from damage.

[0003] However, traditional circuit breakers have several significant defects in practical applications. First, the method of relying on thermal bending sheets as the trigger source of overcurrent protection leads to the problem of poor sensitivity of overcurrent protection, and the performance of the same type of products varies greatly. Secondly, when setting the overcurrent protection, it is difficult to achieve precise control by mechanically adjusting the spring force, which often leads to inaccurate setting of the protection current, which in turn causes the risk of equipment damage. In addition, traditional circuit breakers lack built-in auxiliary signal output points. If their operating status is to be included in the monitoring system, additional sensor elements need to be added, which increases the complexity and cost of the system. More importantly, due to the mechanical contact design, these circuit breakers are prone to sparks during operation, especially when used in flammable and explosive environments, there are major safety hazards; at the same time, mechanical contacts are easily oxidized in high current and humid environments, reducing the conductivity and efficiency. Finally, traditional circuit breakers do not have the function of preventing misoperation, which may bring additional safety risks due to mis-powering. These problems highlight the need for new efficient and safe circuit breaker technologies.

[0004] Therefore, how to provide a DC electronic circuit breaker without mechanical contacts to solve at least one of the above problems. Summary of the invention

[0005] In view of this, the present invention provides a multifunctional DC electronic circuit breaker without mechanical contacts, which has short circuit protection, overcurrent protection, overvoltage and undervoltage protection functions, and is designed with auxiliary control channels, anti-false triggering and other functions.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A multifunctional DC electronic circuit breaker without mechanical contacts, comprising: an MCU main control circuit, an intelligent switch module circuit, a dip switch input circuit and a key input circuit, wherein the intelligent switch module circuit, the dip switch input circuit and the key input circuit are all connected to the MCU main control circuit;

[0008] The intelligent switch module circuit is used for opening and closing control of the main circuit, and at the same time detecting the channel current, voltage and its own temperature value;

[0009] The DIP switch input circuit is used to control the channel current setting and anti-false triggering function;

[0010] The key input circuit is used to open, close or reset the corresponding channel through a mechanical button;

[0011] The MCU main control circuit is used to open or close the channel according to the protection current value set by the dip switch input circuit and the switch instruction of the key input circuit, and to judge the collected current and voltage values, thereby realizing overcurrent protection and overvoltage and undervoltage protection, and performing temperature segmentation compensation according to the temperature value.

[0012] Preferably, it also includes an auxiliary signal output circuit, which is connected to the MCU main control circuit and is used to define the function of the auxiliary channel.

[0013] Preferably, it also includes a signal indicator light circuit, which is connected to the MCU main control circuit and is used to indicate the working status of the DC electronic circuit breaker.

[0014] Preferably, it also includes a main circuit output voltage sampling circuit, and the main circuit output voltage sampling circuit is connected to the intelligent switch module circuit and the MCU main control circuit respectively;

[0015] The main circuit output voltage sampling circuit is used to divide, filter and limit the voltage output by the intelligent switch module circuit and then send it to the MCU main control circuit for ADC sampling.

[0016] Preferably, the intelligent switch module circuit includes a push-pull circuit, a main control loop and an amplifier circuit;

[0017] The push-pull circuit includes an NPN transistor Q3, a PNP transistor Q5 and a resistor R6, the collector of the NPN transistor Q3 is connected to the power input terminal, the base of the NPN transistor Q3 is connected to the resistor R6, the collector of the PNP transistor Q5 is grounded, the base of the PNP transistor Q5 is connected to the connection node between the resistor R6 and the base of the NPN transistor Q3, and the other end of the resistor R6 is connected to the MCU main control circuit;

[0018] The main control loop includes a fuse F1, an NMOS tube Q1, a resistor R4 and a diode D10, wherein the fuse F1 is connected to the source of the NMOS tube Q1, the gate of the NMOS tube Q1 is connected to the connection node of the emitter of the NPN transistor Q3 and the emitter of the PNP transistor Q5 through the resistor R4, the anode of the diode D10 is connected to the connection node of the resistor R4 and the gate of the NMOS tube Q1, and the cathode of the diode D10 is connected to the connection node of the emitter of the NPN transistor Q3 and the emitter of the PNP transistor Q5;

[0019] The amplifier circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R5, a diode D9 and an operational amplifier U1, one end of the resistor R1 is connected to the connection node between the fuse F1 and the source of the NMOS tube Q1, and the other end is connected to the non-inverting input terminal of the operational amplifier U1, one end of the resistor R2 is connected to the drain of the NMOS tube Q1, and the other end is connected to the inverting input terminal of the operational amplifier U1, the diode D9 is connected between the resistor R1 and the resistor R2, the resistor R3 is connected to the connection node between the resistor R1 and the non-inverting input terminal of the operational amplifier U1, one end of the resistor R5 is connected to the output terminal of the operational amplifier U1, and the other end is connected to the connection node between the resistor R2 and the inverting input terminal of the operational amplifier U1.

[0020] Preferably, the intelligent switch module circuit further includes an NTC temperature sensor for monitoring the temperature of the NMOS tube Q1.

[0021] Preferably, the dip switch input circuit includes 10 states. In state 0, the channel is in an anti-false trigger state, and the channel cannot be opened by pressing the mechanical button at this time; states 1-9 are current setting states, which correspond to different current values, and the channel is opened or closed by pressing the mechanical button.

[0022] Preferably, the auxiliary signal output circuit includes a resistor R27, an optocoupler and a diode D39, the positive electrode and the negative electrode of the diode D39 are respectively connected to the collector and the emitter of the optocoupler, the anode of the optocoupler is connected to the power supply, and the cathode of the optocoupler is connected to the MCU main control circuit through the resistor R27.

[0023] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a multifunctional DC electronic circuit breaker without mechanical contacts, which has the following advantages:

[0024] 1) There is no mechanical contact, no arc or tripping noise during operation, no energy storage mechanism, and easy operation.

[0025] 2) Designed with short circuit (long delay fuse), overcurrent, overvoltage and undervoltage protection.

[0026] 3) Auxiliary signals are designed to output control signals of different functions according to requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 A principle block diagram of a multifunctional DC electronic circuit breaker without mechanical contacts provided by the present invention.

[0029] Figure 2 A specific circuit diagram of the MCU main control circuit provided by the present invention.

[0030] Figure 3 This is a specific circuit diagram of the intelligent switch module circuit provided by the present invention.

[0031] Figure 4 The present invention provides a specific circuit diagram of the DIP switch input circuit.

[0032] Figure 5 This is a specific circuit diagram of the key input circuit provided by the present invention.

[0033] Figure 6 A specific circuit diagram of the auxiliary signal output circuit provided by the present invention.

[0034] Figure 7 This is a specific circuit diagram of the signal indicator light circuit provided by the present invention.

[0035] Figure 8 This is a specific circuit diagram of the main loop output voltage sampling circuit provided by the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0037] The embodiment of the present invention discloses a multifunctional DC electronic circuit breaker without mechanical contacts, such as Figure 1As shown, it includes: an MCU main control circuit, an intelligent switch module circuit, a dip switch input circuit and a key input circuit, and the intelligent switch module circuit, the dip switch input circuit and the key input circuit are all connected to the MCU main control circuit;

[0038] The intelligent switch module circuit is used to control the opening and closing of the main circuit, and detect the channel current, voltage and its own temperature value at the same time;

[0039] The DIP switch input circuit is used to control the channel current setting and prevent false triggering functions;

[0040] The key input circuit is used to open, close or reset the corresponding channel through a mechanical button;

[0041] The MCU main control circuit is used to open or close the channel according to the protection current value set by the dip switch input circuit and the switch instruction of the key input circuit, and to judge the collected current and voltage values, thereby realizing overcurrent protection and overvoltage and undervoltage protection, and performing temperature segmentation compensation according to the temperature value.

[0042] Overcurrent protection: After each current and voltage signal sampling, the MCU main control circuit makes a judgment on the current and voltage values ​​of the channel. When the ADC value of the current is greater than the set current value, the overcurrent protection mechanism is triggered, and the MCU main control circuit starts to calculate the delayed trip time and monitor the current change rate at the same time. When the trip time is reached or the current change value is greater than the limit value, the trip is triggered.

[0043] Overvoltage and undervoltage protection: When the voltage value is higher than the upper limit or lower than the lower limit, the corresponding channel is closed. When the voltage is lower than the upper limit recovery voltage and higher than the lower limit recovery voltage, it returns to the closed state. At this time, pressing the button can open the channel.

[0044] It also includes a signal indicator circuit, which is connected to the MCU main control circuit and is used to indicate the working status of the DC electronic circuit breaker. Figure 7 As shown, the status indicator is driven by a serial-input and parallel-output 74HC595 chip. The driver chip is connected to the MCU main control circuit through DS, SCLK, and RCLK signals. The MCU main control circuit is shown in Figure 2 shown.

[0045] The main circuit output voltage sampling circuit is also included, and the main circuit output voltage sampling circuit is connected to the intelligent switch module circuit and the MCU main control circuit respectively; the main circuit output voltage sampling circuit is used to divide, filter and limit the voltage output by the intelligent switch module circuit and then send it to the MCU main control circuit to realize ADC sampling, such as Figure 8 shown.

[0046] Specifically, the present invention is a four-channel DC electronic circuit breaker, each channel corresponds to a signal indicator circuit with a red LED and a green LED, a dip switch input circuit, an intelligent switch module circuit, and a main circuit output voltage sampling circuit.

[0047] The DIP switch input circuit includes 10 states. In state 0, the channel is in the anti-false trigger state. At this time, pressing the mechanical button cannot open the channel. States 1-9 are current setting states, corresponding to different current values, 1A, 2A, 3A, 4A, 5A, 6A, 7A, 8A, and 10A. At this time, pressing the mechanical button can open or close the channel. The green indicator light is on in the open state, and the red indicator light is on in the closed state. Figure 4 As shown, D16-D30 and SW12-SW15 form a 4*4 switch matrix, and the row and column signals of the matrix are led to the CodeSW pin of the MCU main control circuit to read the input status.

[0048] The input circuit of the code switch of the present invention has the function of preventing misoperation, which overcomes the problem that the traditional circuit breaker does not have the function of preventing misoperation and may bring additional safety risks due to mis-power transmission.

[0049] Key input circuit, such as Figure 5 As shown, the key signal is directly led to the KeyIn pin of the MCU main control circuit for status reading.

[0050] like Figure 3 As shown, the intelligent switch module circuit includes a push-pull circuit, a main control loop and an amplifier circuit;

[0051] The push-pull circuit includes an NPN transistor Q3, a PNP transistor Q5 and a resistor R6, the collector of the NPN transistor Q3 is connected to the power input terminal, the base of the NPN transistor Q3 is connected to the resistor R6, the collector of the PNP transistor Q5 is grounded, the base of the PNP transistor Q5 is connected to the connection node of the resistor R6 and the base of the NPN transistor Q3, and the other end of the resistor R6 is connected to the MCU main control circuit;

[0052] The main control circuit includes a fuse F1, an NMOS tube Q1, a resistor R4 and a diode D10. The fuse F1 is connected to the source of the NMOS tube Q1. The gate of the NMOS tube Q1 is connected to the connection node of the emitter of the NPN transistor Q3 and the emitter of the PNP transistor Q5 through the resistor R4. The anode of the diode D10 is connected to the connection node of the resistor R4 and the gate of the NMOS tube Q1. The cathode of the diode D10 is connected to the connection node of the emitter of the NPN transistor Q3 and the emitter of the PNP transistor Q5.

[0053] The amplifier circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R5, a diode D9 and an operational amplifier U1. One end of the resistor R1 is connected to a connection node between the fuse F1 and the source of the NMOS tube Q1, and the other end is connected to the non-inverting input terminal of the operational amplifier U1. One end of the resistor R2 is connected to the drain of the NMOS tube Q1, and the other end is connected to the inverting input terminal of the operational amplifier U1. The diode D9 is connected between the resistor R1 and the resistor R2. The resistor R3 is connected to a connection node between the resistor R1 and the non-inverting input terminal of the operational amplifier U1. One end of the resistor R5 is connected to the output terminal of the operational amplifier U1, and the other end is connected to a connection node between the resistor R2 and the inverting input terminal of the operational amplifier U1.

[0054] It also includes TH1, which is an NTC temperature sensor used to monitor the temperature of NMOS tube Q1. Temperature changes will cause the resistance value of TH1 to change, thereby affecting the current distribution in the circuit and further affecting the ADC sampling value.

[0055] The current sampling loop, the internal resistance voltage drop of the NMOS tube Q1 in the intelligent switch module circuit is amplified by the resistor R1, resistor R2, and diode D9 to the amplifier unit U1. The amplified current signal is amplified by Figure 1 The CS pin is output to the Isensor_1 pin of the MCU main control circuit for ADC sampling.

[0056] Voltage sampling loop, the VS pin of the intelligent switch module circuit outputs the current output voltage, which is led to Figure 8 The main circuit output voltage sampling circuit MainOut end is led to the Vsensor pin of the MCU main control circuit for ADC sampling after resistor voltage division, filtering and limiting.

[0057] The CI pin of the intelligent switch module is the switch control port, which is directly connected to the MCtrl of the MCU.

[0058] The resistor R6 in the intelligent switch module of the present invention is used to limit the base current and ensure the stable operation of Q3 and Q5. The NPN transistor Q3 and the PNP transistor Q5 are used to control the switch state of the NMOS tube Q1. When the MCU sends an "ON" signal, the NPN transistor Q3 is turned on and the PNP transistor Q5 is turned off, so that the gate voltage of Q1 increases, thereby turning on Q1. When the MCU sends an "OFF" signal, the NPN transistor Q3 is turned off and the PNP transistor Q5 is turned on, so that the gate voltage of Q1 decreases, thereby turning off Q1. The fuse F1 is used to protect the circuit from overcurrent damage. The NMOS tube Q1 is used as a switch control device for the main circuit, and the diode D10 is used to prevent the influence of reverse voltage on the circuit. The resistor R4 is used to limit the gate current of Q1. The resistor R5 is a feedback resistor used to adjust the gain of the amplifier. The operational amplifier U1 is used to amplify the internal resistance voltage drop signal of the NMOS tube to a suitable voltage range for MCU sampling.

[0059] The present invention controls the switch state of Q1 through Q3 and Q5 to realize the on-off of the main circuit, uses the internal resistance voltage drop of the NMOS tube to sample the current, and amplifies the signal to the range that can be read by the ADC through the amplifier circuit. The temperature change is monitored by the NTC temperature sensor (TH1), and the temperature compensation is performed by the segmented multi-point compensation algorithm to ensure the measurement accuracy. Due to the parameter differences of the NMOS tube, the on-resistance of different NMOS tubes is not the same, and the on-resistance is also affected by the temperature, so it is necessary to compensate and correct it through the algorithm. When leaving the factory, a certain amount of current is passed through each channel, and the size of its ADC value is read through the debugging interface, and the range is calibrated by the upper computer software. During the aging process, the rated current is passed through each circuit, and the change of its ADC value during the temperature rise process is recorded, and the recorded data is used to perform temperature segmented compensation.

[0060] The present invention adopts an intelligent switch module as the main circuit control element. The element controls the on-off of the circuit current through an NMOS tube and has no mechanical contacts. This overcomes the disadvantages of the prior art that the mechanical contact design is used, the circuit breaker is prone to generate electric sparks during operation, and there are major safety hazards when used in flammable and explosive environments.

[0061] It also includes an auxiliary signal output circuit, which is connected to the MCU main control circuit and is used to define the function of the auxiliary channel. Figure 6As shown, the auxiliary signal output circuit includes a resistor R27, an optical coupler and a diode D39, the positive electrode and the negative electrode of the diode D39 are respectively connected to the collector and the emitter of the optical coupler, the anode of the optical coupler is connected to the power supply, and the cathode of the optical coupler is connected to the MCU main control circuit through the resistor R27. Specifically, the CO and OO terminals output signals to the outside, and the AUX_SIG signal is connected to the Ctrl_Out pin of the MCU main control circuit to control the auxiliary signal output.

[0062] The auxiliary signal output circuit can define the functions of the auxiliary channel according to the on-site control requirements, such as: output overcurrent status output, output undervoltage and overvoltage status output, load status output, etc. The default output is overcurrent status.

[0063] The working process of the present invention is as follows:

[0064] When powered on for the first time, all channels are in the closed state. At this time, the red LED in the signal indicator circuit is on and the green LED is off. When the dip switch is in the 0 position, it means that the channel is in the anti-false trigger state. At this time, pressing the mechanical button of the key input circuit will not turn on the corresponding channel. When the dip switch is in a non-0 state, when the MCU detects that the button is pressed, the MCU sets the CI signal of the corresponding intelligent switch module and records the channel opening state, so that the corresponding channel is turned on. At this time, the green LED is on and the red LED is off.

[0065] After the channel is opened, the CS interface of the intelligent switch module outputs a current signal, and the VS interface outputs a voltage signal. The CS signal is sampled by the ADC port of the MCU, and the VS signal is filtered and limited by the main circuit output voltage sampling circuit and then sent to the ADC port of the MCU for sampling. After each current and voltage signal sampling, the MCU makes a judgment on the current and voltage values ​​of the channel. When the ADC value of the current is greater than the set current value, the overcurrent protection mechanism is triggered, and the MCU starts to calculate the delayed trip time and monitor the current change rate at the same time. When the trip time is reached or the current change value is greater than the limit value, the trip is triggered. At this time, the MCU resets the CI pin of the intelligent switch module, closes the channel, and at the same time, the MCU opens the auxiliary channel and outputs an alarm signal. At this time, the red LED flashes and the green LED goes out, indicating an overcurrent state. The channel is in a forced cooling state, and the button cannot open the channel. After the forced cooling state, the red LED flashes and the green LED flashes, indicating that the channel is in a reset state. At this time, press the button of the corresponding channel to reset. After the reset, the channel remains in the open / closed state before the overcurrent. When all channels are in a non-alarm state, the MCU turns off the alarm signal of the auxiliary channel. While monitoring the current, the MCU filters the voltage value collected by the VS interface to remove surge and harmonic interference. When the voltage value is higher than the upper limit or lower than the lower limit, the corresponding channel is closed. When the voltage is lower than the upper limit recovery voltage and higher than the lower limit recovery voltage, it returns to the closed state. At this time, pressing the button can open the channel.

[0066] In the on state, when the button is pressed, the MCU resets the CI pin of the intelligent switch module and records the channel closing state. At this time, the red LED lights up and the green LED goes out.

[0067] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0068] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multifunctional DC electronic circuit breaker without mechanical contacts, characterized in that: include: MCU main control circuit, intelligent switch module circuit, DIP switch input circuit and key input circuit, wherein the intelligent switch module circuit, the DIP switch input circuit and the key input circuit are all connected to the MCU main control circuit; The intelligent switch module circuit is used for opening and closing control of the main circuit, and at the same time detecting the channel current, voltage and its own temperature value; The DIP switch input circuit is used to control the channel current setting and anti-false triggering function; The key input circuit is used to open, close or reset the corresponding channel through a mechanical button; The MCU main control circuit is used to open or close the channel according to the protection current value set by the dip switch input circuit and the switch instruction of the key input circuit, and to judge the collected current and voltage values, thereby realizing overcurrent protection and overvoltage and undervoltage protection, and performing temperature segmentation compensation according to the temperature value.

2. A multifunctional DC electronic circuit breaker without mechanical contacts according to claim 1, characterized in that: It also includes an auxiliary signal output circuit, which is connected to the MCU main control circuit and is used to define the function of the auxiliary channel.

3. A multifunctional DC electronic circuit breaker without mechanical contacts according to claim 1, characterized in that: It also includes a signal indicator light circuit, which is connected to the MCU main control circuit and is used for indicating the working status of the DC electronic circuit breaker.

4. The multifunctional DC electronic circuit breaker without mechanical contacts according to claim 1, characterized in that: It also includes a main circuit output voltage sampling circuit, which is connected to the intelligent switch module circuit and the MCU main control circuit respectively; The main circuit output voltage sampling circuit is used to divide, filter and limit the voltage output by the intelligent switch module circuit and then send it to the MCU main control circuit for ADC sampling.

5. The multifunctional DC electronic circuit breaker without mechanical contacts according to claim 1, characterized in that: The intelligent switch module circuit includes a push-pull circuit, a main control loop and an amplifier circuit; The push-pull circuit includes an NPN transistor Q3, a PNP transistor Q5 and a resistor R6, the collector of the NPN transistor Q3 is connected to the power input terminal, the base of the NPN transistor Q3 is connected to the resistor R6, the collector of the PNP transistor Q5 is grounded, the base of the PNP transistor Q5 is connected to the connection node between the resistor R6 and the base of the NPN transistor Q3, and the other end of the resistor R6 is connected to the MCU main control circuit; The main control loop includes a fuse F1, an NMOS tube Q1, a resistor R4 and a diode D10, wherein the fuse F1 is connected to the source of the NMOS tube Q1, the gate of the NMOS tube Q1 is connected to the connection node of the emitter of the NPN transistor Q3 and the emitter of the PNP transistor Q5 through the resistor R4, the anode of the diode D10 is connected to the connection node of the resistor R4 and the gate of the NMOS tube Q1, and the cathode of the diode D10 is connected to the connection node of the emitter of the NPN transistor Q3 and the emitter of the PNP transistor Q5; The amplifier circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R5, a diode D9 and an operational amplifier U1, one end of the resistor R1 is connected to the connection node between the fuse F1 and the source of the NMOS tube Q1, and the other end is connected to the non-inverting input terminal of the operational amplifier U1, one end of the resistor R2 is connected to the drain of the NMOS tube Q1, and the other end is connected to the inverting input terminal of the operational amplifier U1, the diode D9 is connected between the resistor R1 and the resistor R2, the resistor R3 is connected to the connection node between the resistor R1 and the non-inverting input terminal of the operational amplifier U1, one end of the resistor R5 is connected to the output terminal of the operational amplifier U1, and the other end is connected to the connection node between the resistor R2 and the inverting input terminal of the operational amplifier U1.

6. A multifunctional DC electronic circuit breaker without mechanical contacts according to claim 5, characterized in that: The intelligent switch module circuit also includes an NTC temperature sensor for monitoring the temperature of the NMOS tube Q1.

7. A multifunctional DC electronic circuit breaker without mechanical contacts according to claim 1, characterized in that: The dip switch input circuit includes 10 states. In state 0, the channel is in an anti-false trigger state, and the channel cannot be opened by pressing the mechanical button; states 1-9 are current setting states, corresponding to different current values, and the channel is opened or closed by pressing the mechanical button.

8. The multifunctional DC electronic circuit breaker without mechanical contacts according to claim 2, characterized in that: The auxiliary signal output circuit includes a resistor R27, an optocoupler and a diode D39, wherein the positive electrode and the negative electrode of the diode D39 are respectively connected to the collector and the emitter of the optocoupler, the anode of the optocoupler is connected to a power supply, and the cathode of the optocoupler is connected to the MCU main control circuit through the resistor R27.

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