A high-precision fuse control circuit and method

Abstract

This invention belongs to the technical field of circuit design, specifically relating to a high-precision fuse control circuit. It includes an electrically connected reference voltage acquisition module, an electrical signal acquisition module, a voltage comparison module, a main control module, and a constant current trigger circuit. The reference voltage acquisition module provides the acquired voltage value, the electrical signal acquisition module provides a voltage detection value after gain amplification, the voltage comparison module compares the acquired voltage value and the voltage detection value, the main control module acquires analog and digital signals, and the constant current trigger circuit outputs the required electrical signal. The circuit of this invention has high response accuracy, enabling safe, accurate, and rapid response. Furthermore, its signal acquisition performance is superior, providing a stable reference potential to avoid interference from harmful electromagnetic fields. The circuit also achieves constant current output, thereby protecting the power supply system. In addition, this invention also provides a high-precision fuse control method.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit design, and in particular relates to a high-precision fuse control circuit and method. Background Art

[0002] Fuses are commonly used electrical components that can protect circuits. Moreover, fuses can be widely used in high and low voltage power distribution systems and control systems as well as electrical equipment. As a short circuit and overcurrent protector, they are one of the most commonly used protection devices. At the same time, with the development and gradual popularization of new energy vehicles, new energy vehicles use a large number of battery packs. When a short circuit occurs in the battery pack, the existing circuit not only has a weak monitoring capability for the corresponding short-circuit electrical signal, but also has low response accuracy and poor controllability. In addition, the existing circuit also has the problem of poor operating logic capability, and cannot safely and accurately perform the required fuse response in an anti-interference manner. To this end, it is urgent to propose a new technical solution to solve the above problems. Summary of the invention

[0003] One of the purposes of the present invention is to address the deficiencies in the prior art and to provide a high-precision fuse control circuit, which can respond safely and accurately in fuse control to trigger the required fuse. At the same time, its signal acquisition performance is better, and the signal has a stable reference potential, thereby avoiding interference from harmful electromagnetic fields. In addition, the circuit also achieves constant current output, thereby protecting the power supply system.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A high-precision fuse control circuit, comprising:

[0006] A reference voltage acquisition module, having a voltage reference chip, for providing an acquisition voltage value;

[0007] The electrical signal acquisition module has a first operational amplifier unit for providing a voltage detection value after gain amplification;

[0008] A voltage comparison module, comprising a second operational amplifier unit and a digital signal output unit electrically connected, wherein the voltage reference chip and the first operational amplifier unit are electrically connected to an input end of the second operational amplifier unit, respectively, to compare the collected voltage value with the voltage detection value;

[0009] A main control module, electrically connected to the first operational amplifier unit and the digital signal output unit, respectively, and used for collecting analog signals and digital signals;

[0010] The constant current trigger circuit comprises an electrically connected driving module and a constant current output module, wherein the input end of the driving module is electrically connected to the main control module, and the output ends of the driving module and the constant current output module are used to output the required electrical signals.

[0011] Furthermore, the electrical signal acquisition module also has a shunt, a first resistor and a first filtering unit connected in sequence, the first operational amplifier unit is respectively connected to the first filtering unit and the second operational amplifier unit, and the first operational amplifier unit is connected to the ADC signal end of the main control module through the second resistor.

[0012] Furthermore, the digital signal output unit has an optical coupler, and the optical coupler is electrically connected to the output end of the second operational amplifier unit and the INT0 signal end of the main control module respectively.

[0013] Furthermore, the driving module includes a first field effect unit and a second field effect unit electrically connected, the constant current output module includes a third operational amplifier unit and a third field effect unit electrically connected, and the second field effect unit is connected to the third field effect unit through the third operational amplifier unit.

[0014] Furthermore, the PS_ON signal terminal of the main control module is connected to the gate of the first field effect unit through a first modulation resistor, the drain of the first field effect unit is connected to the gate of the second field effect unit through a second modulation resistor, and the drain of the second field effect unit is connected to the third operational amplifier unit.

[0015] Furthermore, the in-phase input terminal of the third operational amplifier unit is connected to an RC parallel unit, and the reference voltage signal terminal of the reference voltage acquisition module is sequentially connected to the RC parallel unit and the in-phase input terminal through a third modulation resistor.

[0016] Furthermore, the inverting input terminal of the third operational amplifier unit is sequentially connected to a fourth modulation resistor, a fifth modulation resistor and a ground signal terminal, and the series terminal of the fourth modulation resistor and the fifth modulation resistor is connected to the source of the third field effect unit.

[0017] Furthermore, the output end of the third operational amplifier unit is connected to the gate of the third field effect unit through a sixth modulation resistor.

[0018] Furthermore, the reference voltage acquisition module has a second filtering unit electrically connected to the voltage reference chip, the voltage reference chip is located between the second filtering unit and the second operational amplifier unit, and the input end of the voltage reference chip and the RC parallel unit are both connected to the ground signal end.

[0019] The second object of the present invention is to provide a high-precision fuse control method, comprising the following steps:

[0020] S1, connect the reference voltage acquisition module and the electrical signal acquisition module to the comparison module respectively, and then connect the electrical signal acquisition module and the comparison module to the main control module respectively to collect the required analog signals and digital signals;

[0021] S2, connecting the main control module to the driving module of the constant current trigger circuit, and outputting a safety electrical signal or a trigger electrical signal at the output end of the driving module of the constant current trigger circuit and the constant current output module.

[0022] The beneficial effects of the present invention are as follows: 1) The fuse control circuit of the present invention comprises an electrically connected reference voltage acquisition module, an electrical signal acquisition module, a voltage comparison module, a main control module and a constant current trigger circuit, wherein the reference voltage acquisition module is used to provide an acquisition voltage value, the electrical signal acquisition module is used to provide a voltage detection value after gain amplification, the voltage comparison module is used to compare the acquisition voltage value and the voltage detection value, the main control module is used to acquire analog signals and digital signals, and the constant current trigger circuit is used to output the required electrical signal to achieve the required fuse control. Under the logical operation of the main control module, the constant current trigger circuit and other modules, the overall operation of the circuit The logic is strong, the hardware can be real-time logical, and respond to the output at high speed and high precision, thereby triggering the required fuse; 2) The main control module of the present invention can analyze digital signals and analog signals at the same time, so as to solve some special or complex situations; 3) The reference voltage acquisition module of the present invention has a voltage reference chip, which can adopt negative terminal acquisition to make the signal acquisition performance better, and the signal can have a stable reference potential, thereby avoiding interference from harmful electromagnetic fields; 4) The constant current trigger circuit of the present invention includes an electrically connected drive module and a constant current output module, which can achieve constant current output, thereby protecting the power supply system of the control circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a circuit diagram of an electrical signal acquisition module, a reference voltage acquisition module and a voltage comparison module in a fuse control circuit.

[0024] Figure 1a for Figure 1 Circuit diagram of the electrical signal acquisition module in .

[0025] Figure 1b for Figure 1 Circuit diagram of the reference voltage acquisition module in .

[0026] Figure 1c for Figure 1 Circuit diagram of the voltage comparison module in .

[0027] Figure 2 It is a circuit diagram of the main control module in the fuse control circuit of the present invention.

[0028] Figure 3 The circuit diagram of the constant current trigger circuit in the fuse control circuit of the present invention.

[0029] Figure 3a This is a circuit diagram of the first field effect unit in the constant current trigger circuit.

[0030] Figure 3b This is a circuit diagram of the second field effect unit in the constant current trigger circuit.

[0031] Figure 3c This is the circuit diagram of the constant current output module in the constant current trigger circuit.

[0032] Figure 4 It is a circuit diagram of a power supply module in the fuse control circuit of the present invention.

[0033] Figure 5 It is a schematic diagram of the fuse control circuit of the present invention. DETAILED DESCRIPTION

[0034] If certain words are used in the specification and claims to refer to specific components, those skilled in the art should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. As mentioned throughout the specification and claims, "including" is an open term and should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0035] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", "horizontal", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0036] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0037] The following is combined with Figures 1 to 5The present invention is further described in detail with reference to the following specific embodiments, but is not intended to limit the present invention.

[0038] A high-precision fuse control circuit, such as Figure 5 As shown, it includes an electrically connected reference voltage acquisition module, an electrical signal acquisition module, a voltage comparison module, a main control module and a constant current trigger circuit, wherein the reference voltage acquisition module is used to provide an acquisition voltage value, the electrical signal acquisition module is used to provide a voltage detection value after gain amplification, the voltage comparison module is used to compare the acquisition voltage value and the voltage detection value, the main control module is used to acquire analog signals and digital signals, and the constant current trigger circuit is used to output the required electrical signal, thereby realizing the corresponding fuse control. In the specific circuit, the reference voltage acquisition module has a voltage reference chip that can provide a reference voltage, and the electrical signal acquisition module includes a shunt, a first resistor R1, a first filtering unit and a first operational amplifier unit U1-A that are connected in sequence. When current passes through the precision resistor shunt, a voltage signal is obtained according to Ohm's law, and then through Figure 1a The circuit makes high gain amplification for comparison and judgment. The voltage comparison module includes a second operational amplifier unit and a digital signal output unit electrically connected. The voltage reference chip and the first operational amplifier unit U1-A are respectively electrically connected to the input end of the second operational amplifier unit to compare the collected voltage value and the voltage detection value. The main control module is respectively electrically connected to the first operational amplifier unit U1-A and the digital signal output unit. The first operational amplifier unit U1-A outputs an analog signal for the main control module to analyze the real-time current situation. The second operational amplifier unit Figure 1a The circuit results are Figure 1b After real-time comparison of the circuit results, the digital level signal is output through the digital signal output unit and sent to the main control module. The constant current trigger circuit includes an electrically connected drive module and a constant current output module. The input end of the drive module is electrically connected to the main control module. After the main control module analyzes the received signal, it drives the MOS tube in the constant current trigger circuit through the PS_ON digital signal. In the constant current output module, the sampling resistor and the reference voltage are calculated to make the output current constant at 1.25A. This not only protects the stability of the power supply system, but also controls the electrical signals at the output ends of the drive module and the constant current output module. Under the electrical control logic of the above circuit, the required fuse is triggered.

[0039] See also Figure 1 and Figure 1aIn the electrical signal acquisition module of the fuse control circuit, the first operational amplifier unit U1-A is connected to the first filtering unit and the second operational amplifier unit U1-B respectively, and the first operational amplifier unit U1-A is connected to the ADC signal end of the main control module through the second resistor R8. Among them, the first filtering unit includes an electrically connected capacitor C4, a resistor R12 and a capacitor C5, a shunt, a resistor R1, a capacitor C4 and a capacitor C5 are connected in parallel in sequence, the resistor R12 is connected to the capacitor C4 and the capacitor C5 respectively, one end of the resistor R12 and one end of the capacitor C5 are connected to the in-phase input terminal of the first operational amplifier unit U1-A, the other end of the capacitor C5 is connected to the inverting input terminal of the first operational amplifier unit U1-A through the resistor R13, one end of the shunt, one end of the resistor R1, one end of the capacitor C4, the other end of the capacitor C5, one end of the resistor R13 and one of the pins of the first operational amplifier unit U1-A are connected to the ground signal terminal, and at the same time, another pin of the first operational amplifier unit U1-A is connected to a 12V DC voltage, and the 12V DC voltage can be provided by a power supply module in the circuit, and the output terminal and the inverting input terminal of the first operational amplifier unit U1-A are connected with a resistor R14.

[0040] See also Figure 1 and Figure 1b In the reference voltage acquisition module of the fuse control circuit, the reference voltage acquisition module has a second filtering unit electrically connected to the voltage reference chip U2, and the voltage reference chip U2 is located between the second filtering unit and the second operational amplifier unit U1-B, wherein the model of the voltage reference chip U2 is TL431AIDBZR, and the second filtering unit includes an electrically connected capacitor C1 and a resistor R5, one end of the capacitor C1 and one end of the resistor R5 are connected with a 5V DC voltage, and the 5V DC voltage can be obtained by a power supply module in the circuit after a 12V to 5V DC conversion, the other end of the capacitor C1 and the input end of the voltage reference chip U2 are connected with a ground signal end, the other end of the resistor R5 is connected to the voltage reference chip U2 and the VREF signal end, and the output end of the voltage reference chip U2 can output a 2.5V DC voltage.

[0041] See also Figure 1 and Figure 1c In the voltage comparison module of the fuse control circuit, the digital signal output unit in the circuit has an optical coupler OS1, wherein the input end of the optical coupler OS1 is connected to a 12V DC voltage through a resistor R7, and the 12V DC voltage can be provided by a power supply module in the circuit. In the circuit, the optical coupler OS1 is electrically connected to the output end of the second operational amplifier unit U1-B and the INT0 signal end of the main control module, respectively, see Figure 1c, an LED is connected between the optocoupler OS1 and the second op amp unit U1-B, the pin of the optocoupler OS1 connected to the INT0 signal end is connected to a 5V DC voltage through a resistor R6, and the 5V DC voltage can be obtained by the power supply module in the circuit after a 12V to 5V DC conversion, and the other output pin of the optocoupler OS1 is connected to the ground signal end. In addition, the first op amp unit U1-A and the second op amp unit U1-B can use LM358 op amp chips, the first op amp unit U1-A is connected to the inverting input end of the second op amp unit U1-B, and the voltage reference chip U2 is connected to the non-inverting input end of the second op amp unit U1-B. By comparing the collected voltage value and the detected voltage value stably in this way, the digital level signal is transmitted to the control unit U6 in the main control module through the optocoupler OS1, and the control unit U6 processes the digital level signal and then transmits the required voltage to the drive module.

[0042] See also Figure 2 In the main control module of the fuse control circuit, the control unit U6 can be a single chip microcomputer of model STC8G1K17A. On the one hand, the control unit U6 collects the analog signal output by the first operational amplifier unit U1-A through the ADC signal terminal, and on the other hand, the control unit U6 collects the digital level signal output by the optical coupler OS1 through the INT0 signal terminal. When the circuit is running, the corresponding control program can be input to the control unit U6. Among them, the main control module has an interface J3 electrically connected to the control unit U6, so that the required program can be input from the interface J3 to the TX1 signal terminal and the RX1 signal terminal of the control unit U6. In addition, the VCC signal terminal of the control unit U6 is connected to the 5V DC voltage through the resistor R17, and the VCC signal terminal of the control unit U6 is connected to the VREF signal terminal through the resistor R18, which ensures the normal operation of the circuit and reliable and safe operation.

[0043] See also Figure 3 In the constant current trigger circuit of the fuse control circuit, the driving module includes a first field effect unit Q5 and a second field effect unit Q2 that are electrically connected, the constant current output module includes a third operational amplifier unit U3-A and a third field effect unit Q3 that are electrically connected, and the second field effect unit Q2 is connected to the third field effect unit Q3 through the third operational amplifier unit U3-A.

[0044] See also Figure 3 and Figure 3aThe PS_ON signal end of the main control module is connected to the gate of the first field effect unit Q5 through the first modulation resistor R16, and the control unit U6 of the main control module drives the first field effect unit Q5 and the second field effect unit Q2 through the PS_ON digital signal. One end of the resistor R15 is connected to the gate of the first field effect unit Q5, and the other end of the resistor R15 is connected to the ground signal end, wherein the first field effect unit Q5 can be an N-channel enhancement MOS tube with model 2N7002.

[0045] See also Figure 3 and Figure 3b , the drain of the first field effect unit Q5 is connected to the gate of the second field effect unit Q2 through the second modulation resistor R10, the second field effect unit Q2 can be a P-channel enhancement type MOS tube of model D413A, and the drain of the second field effect unit Q2 is connected to the third operational amplifier unit U3-A to provide a 12V DC voltage to the third operational amplifier unit U3-A. Among them, the source of the second field effect unit Q2 is connected to the 12V DC voltage, one end of the resistor R11 is connected to one end of the resistor R10 and the gate of the second field effect unit Q2, the other end of the resistor R11 is connected to the source of the second field effect unit Q2, one end of the capacitor C3 is connected to one end of the resistor R10 and the gate of the second field effect unit Q2, and the other end of the capacitor C3 is connected to the ground signal terminal.

[0046] See also Figure 3 and Figure 3c , the in-phase input terminal of the third operational amplifier unit U3-A is connected to the RC parallel unit, and the reference voltage signal terminal VREF of the reference voltage acquisition module is sequentially connected to the RC parallel unit and the in-phase input terminal of the third operational amplifier unit U3-A through the third modulation resistor R22. Specifically, the RC parallel unit includes a capacitor C2 and a resistor R23 connected in parallel, one end of the capacitor C2 and the resistor R23 is connected to the ground signal terminal, and the VREF signal terminal is connected to the in-phase input terminal of the third operational amplifier unit U3-A through the resistor R22, and the required DC voltage is input to the third operational amplifier unit U3-A by performing calculation with the reference voltage through the resistor R22.

[0047] In addition, the inverting input terminal of the third operational amplifier unit U3-A is connected to the fourth modulation resistor R2, the fifth modulation resistor R9 and the ground signal terminal in sequence, and the series connection terminal of the fourth modulation resistor R2 and the fifth modulation resistor R9 is connected to the source of the third field effect unit Q3, see Figure 3cA resistor R4 is connected between a pin of the third operational amplifier unit U3-A connected to the ground signal terminal and the gate of the third field effect unit Q3, and the output terminal of the third operational amplifier unit U3-A is connected to the gate of the third field effect unit Q3 through the sixth modulation resistor R3. The third operational amplifier unit U3-A can use an LM358 operational amplifier chip, and the third field effect unit Q3 can be an N-channel enhancement MOS tube of model IRFR120N. Under the above circuit operation logic, the output current is kept constant at 1.25A by operating the resistor and the reference voltage to ensure the safe operation of the circuit.

[0048] In some embodiments, see Figure 4 The fuse control circuit includes a power supply module, which has an LM7805CT voltage regulator chip to ensure that the 12V DC voltage is stably converted into a 5V DC voltage.

[0049] A high-precision fuse control method comprises the following steps:

[0050] S1, connect the reference voltage acquisition module and the electrical signal acquisition module to the comparison module respectively, and then connect the electrical signal acquisition module and the comparison module to the main control module respectively to collect the required analog signals and digital signals;

[0051] S2, connecting the main control module to the driving module of the constant current trigger circuit, and outputting a safety electrical signal or a trigger electrical signal at the output end of the driving module of the constant current trigger circuit and the constant current output module.

[0052] When detecting whether a short circuit occurs in the battery pack, the battery pack to be detected is connected to the input end of the shunt, and the fuse is connected to the drain of the second field effect unit Q2 and the drain of the third field effect unit Q3. Through the electrically connected reference voltage acquisition module, electrical signal acquisition module, voltage comparison module, main control module and constant current trigger circuit, the reference voltage acquisition module is used to provide a collected voltage value, the electrical signal acquisition module is used to provide a voltage detection value after gain amplification, the voltage comparison module is used to compare the collected voltage value and the voltage detection value, the main control module is used to collect analog signals and digital signals, and the constant current trigger circuit is used to output the required electrical signal, thereby realizing corresponding fuse control. In this way, when a short circuit occurs in the battery pack, the fuse can be safely blown in the shortest time, so that the fuse control circuit can respond to the output at high speed and high precision, so that it can respond safely, accurately and quickly, and then trigger the required fuse.

[0053] Obviously, the present invention can respond accurately and quickly with high precision, and thus trigger the required fuse with high precision and intelligence. At the same time, its signal acquisition performance is better, and the signal has a stable reference potential, thereby avoiding interference from harmful electromagnetic fields. Moreover, the circuit also realizes constant current output, thereby protecting the power supply system.

[0054] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A high-precision fuse control circuit, characterized in that: include: A reference voltage acquisition module, having a voltage reference chip, for providing an acquisition voltage value; The electrical signal acquisition module has a first operational amplifier unit for providing a voltage detection value after gain amplification; A voltage comparison module, comprising a second operational amplifier unit and a digital signal output unit electrically connected, wherein the voltage reference chip and the first operational amplifier unit are electrically connected to the input end of the second operational amplifier unit respectively to compare the collected voltage value with the voltage detection value, and the digital signal output unit has an optical coupler, and the optical coupler is electrically connected to the output end of the second operational amplifier unit; A main control module, electrically connected to the first operational amplifier unit and the digital signal output unit, respectively, for collecting analog signals and digital signals, and an INT0 signal terminal of the main control module is electrically connected to the optical coupler; A constant current trigger circuit, comprising an electrically connected driving module and a constant current output module, wherein the input end of the driving module is electrically connected to the main control module, the driving module comprises an electrically connected first field effect unit and a second field effect unit, the constant current output module comprises an electrically connected third operational amplifier unit and a third field effect unit, the second field effect unit is connected to the third field effect unit through the third operational amplifier unit, a PS_ON signal end of the main control module is connected to a gate of the first field effect unit through a first modulation resistor, a drain of the first field effect unit is connected to a gate of the second field effect unit through a second modulation resistor, and a drain of the second field effect unit is connected to the third operational amplifier unit; The output ends of the driving module and the constant current output module are used to output the required electrical signals to achieve the required fusing control.

2. The high-precision fuse control circuit according to claim 1, characterized in that: The electrical signal acquisition module also has a shunt, a first resistor and a first filtering unit connected in sequence, the first operational amplifier unit is respectively connected to the first filtering unit and the second operational amplifier unit, and the first operational amplifier unit is connected to the ADC signal end of the main control module through the second resistor.

3. The high-precision fuse control circuit according to claim 1, characterized in that: The in-phase input terminal of the third operational amplifier unit is connected to an RC parallel unit, and the reference voltage signal terminal of the reference voltage acquisition module is sequentially connected to the RC parallel unit and the in-phase input terminal through a third modulation resistor.

4. The high-precision fuse control circuit according to claim 1, characterized in that: The inverting input terminal of the third operational amplifier unit is sequentially connected to the fourth modulation resistor, the fifth modulation resistor and the ground signal terminal, and the series terminal of the fourth modulation resistor and the fifth modulation resistor is connected to the source of the third field effect unit.

5. The high-precision fuse control circuit according to claim 1, characterized in that: The output end of the third operational amplifier unit is connected to the gate of the third field effect unit through a sixth modulation resistor.

6. The high-precision fuse control circuit according to claim 3, characterized in that: The reference voltage acquisition module has a second filtering unit electrically connected to the voltage reference chip, the voltage reference chip is located between the second filtering unit and the second operational amplifier unit, and the input end of the voltage reference chip and the RC parallel unit are both connected to the ground signal end.

7. A high-precision fusing control method, used in the fusing control circuit according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1, respectively connect the reference voltage acquisition module and the electrical signal acquisition module to the comparison module, and then respectively connect the electrical signal acquisition module and the comparison module to the main control module to collect the required analog signals and digital signals; S2, connecting the main control module to the driving module of the constant current trigger circuit, and outputting a safety electrical signal or a trigger electrical signal at the output end of the driving module of the constant current trigger circuit and the constant current output module.

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