Carrying type automobile electronic fuse

Abstract

A carrying type automobile electronic fuse is characterized in that a starting circuit is arranged, the input end of the starting circuit obtains an input power source, and the output end of the starting circuit outputs working voltage to a load; the starting circuit is provided with a current detection end which is connected with the overcurrent protection circuit. The output end of the overcurrent protection circuit is connected with the overcurrent input end of the logic judgment circuit. The starting circuit is provided with a voltage detection end which is connected with the overvoltage protection circuit and the under-voltage protection circuit, the output end of the overvoltage protection circuit is connected with the overvoltage input end of the logic judgment circuit, and the output end of the under-voltage protection circuit is connected with the under-voltage input end of the logic judgment circuit; the heating element of the starting circuit is connected with a temperature sensor of an over-temperature protection circuit, and the output end of the over-temperature protection circuit is connected with the over-temperature input end of the logic judgment circuit; the output end of the logic judgment circuit is connected with the input end of the control starting isolation circuit, and the control starting isolation circuit controls the starting circuit. The power supply has the effects of overvoltage, undervoltage, overcurrent, over-temperature and short-circuit protection functions, low use cost and software parameter adjustment function.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic fuse technical field especially, it is a kind of vehicle electronic fuse of mounting type. BACKGROUND

[0002] Fuse is also called fuse, and its main is overload protection function. The purpose of automobile fuse is similar to the function of household fuse, and the fuse is correctly placed in the circuit, and when the current abnormally rises to a certain height and heat, the fuse itself is fused to cut off the current, protecting the safe operation of the circuit.

[0003] Traditional fuse function is single, can only be used as current-limiting off type fuse, and replacement operability is poor, because it is mostly installed in the automobile internal fuse box, therefore needs to be replaced only by disassembling shell and unloading fastening screw, and the current market mainstream integrated electronic fuse is high in cost, function is limited and poor in thermal management effect.

[0004] Prior art defects: the existing fuse is either single function and poor in replacement operability, or high in cost, function is limited and poor in thermal management effect. INVENTION CONTENTS

[0005] The vehicle electronic fuse of mounting type provided by the utility model has overvoltage, undervoltage, overcurrent and overtemperature protection functions.

[0006] To achieve the above-mentioned purpose, the vehicle electronic fuse of mounting type provided by the utility model, the key is: startup circuit, overcurrent protection circuit, overtemperature protection circuit, undervoltage protection circuit, overvoltage protection circuit, logic judgment circuit and control startup isolation circuit are arranged.

[0007] The input end of the startup circuit obtains input power supply, and the output end outputs working voltage to load;

[0008] The startup circuit is provided with current detection end connected with overcurrent protection circuit, and the output end of the overcurrent protection circuit is connected with overcurrent input end of the logic judgment circuit;

[0009] The startup circuit is provided with voltage detection end connected with overvoltage protection circuit and undervoltage protection circuit, the output end of the overvoltage protection circuit is connected with overvoltage input end of the logic judgment circuit, and the output end of the undervoltage protection circuit is connected with undervoltage input end of the logic judgment circuit;

[0010] The temperature sensor of overtemperature protection circuit is connected to the heating element of the startup circuit, and the output end of the overtemperature protection circuit is connected with overtemperature input end of the logic judgment circuit;

[0011] The output end of the logic judgment circuit is connected with the input end of control startup isolation circuit, and the output end of the control startup isolation circuit controls the startup circuit.

[0012] By the above design, the overcurrent protection circuit, the overtemperature protection circuit, the undervoltage protection circuit and the overvoltage protection circuit are used to realize the overcurrent, overtemperature, undervoltage, overvoltage and short circuit protection functions of the circuit.

[0013] When the circuit is not in any of the overcurrent, overtemperature, undervoltage and overvoltage states, the logic judgment circuit outputs a high-level signal to the control start isolation circuit, the control start isolation circuit is turned on, and then a high-level signal is output to control the stable output of the start circuit; otherwise, the logic judgment circuit outputs a low-level signal to the control start isolation circuit, the control start isolation circuit is turned off, and then the start circuit is closed, the voltage output is stopped, and the protection function is achieved.

[0014] As a preferred, the start circuit is provided with a MOS tube Q2, the source electrode of the MOS tube Q2 is connected to the input power supply, the gate electrode is connected to the input power supply through a voltage dividing resistor R1, and the gate electrode is also connected to a low-level through a voltage dividing resistor R2, and the drain electrode of the MOS tube Q2 is connected to a load through a resistor R11.

[0015] The front end of the resistor R11 is provided with a first current detection end, and the rear end is provided with a second current detection end and a voltage detection end; and the MOS tube Q2 is connected with a temperature sensor.

[0016] The MOS tube Q2 is turned on through the judgment of the gate-source voltage Vgs and the threshold voltage, and the start circuit outputs a working voltage to the load.

[0017] As a preferred, the overcurrent protection circuit is provided with a resistor R32, the front end of the resistor R32 is connected to the second current detection end, and the rear end is connected to the ground through a resistor R33; the common end of the resistor R32 and the resistor R33 is connected to the positive input end of an operational amplifier U2A, the negative input end of the operational amplifier U2A is connected to the ground through a resistor R35, and the negative input end of the operational amplifier U2A is also connected to the output end of the operational amplifier U2A through a resistor R34, and the output end is connected to the negative input end of an operational amplifier U2B through a resistor R31.

[0018] The negative input end of the operational amplifier U2B is also connected to the output end through a resistor R29, the positive input end of the operational amplifier U2B is connected to the first current detection end through a resistor R17, and the positive input end is also connected to the ground through a resistor R18 and a resistor R19 in sequence, and the output end of the operational amplifier U2B is connected to the positive input end of an operational amplifier U4B through a resistor R23.

[0019] The negative input terminal of the operational amplifier U4B obtains the over-current protection parameter, and the negative input terminal is also connected with the ground through a capacitor C15. The output terminal of the operational amplifier U4B is connected with the 5V power supply through a resistor R22, and the output terminal is also connected with the ground through a capacitor C14, and the output terminal is also connected with the ground through a bidirectional breakdown diode D5. The output terminal of the operational amplifier U4B is also connected with the gate of a MOS tube Q3 through a resistor R26, the drain of the MOS tube Q3 is connected with the ground, and the source of the MOS tube Q3 is connected with the logic judgment circuit. The source of the MOS tube Q3 is also connected with the 5V power supply through a resistor R20.

[0020] The operational amplifier U4B is used as a comparator for comparing the output voltage value of the operational amplifier U2B with the over-current protection parameter. When the output signal of the operational amplifier U4B is a low level, it indicates that the circuit is normal and is not in an over-current state. Otherwise, it is in an over-current state.

[0021] The MOS tube Q3 is turned on when the output signal of the operational amplifier U4B is a low level, and then a high level signal is output to the logic judgment circuit. The MOS tube Q3 is turned off when the output signal of the operational amplifier U4B is a high level, and then a low level signal is output to the logic judgment circuit.

[0022] As a preferred, the over-temperature protection circuit is provided with a thermistor R52, the thermistor R52 is connected with the heating element of the starting circuit, the front end of the thermistor R52 is connected with the 5V power supply, and the rear end is connected with the ground through a resistor R48. The common end of the thermistor R52 and the resistor R48 is connected with the positive input terminal of an operational amplifier U5A. The negative input terminal of the operational amplifier U5A is connected with the ground through a resistor R55, and the negative input terminal of the operational amplifier U5A is also connected with the output terminal of the operational amplifier U5A through a resistor R53. The output terminal of the operational amplifier U5A is connected with the negative input terminal of an operational amplifier U5B through a resistor R46.

[0023] The negative input terminal of the operational amplifier U5B is also connected with the output terminal through a resistor R45. The positive input terminal of the operational amplifier U5B is connected with the front end of the thermistor R52 through a resistor R40, and the positive input terminal is also connected with the ground through a resistor R41. The output terminal of the operational amplifier U5B is connected with the positive input terminal of an operational amplifier U4A through a resistor R39.

[0024] The negative input terminal of the operational amplifier U4A obtains the over-temperature protection parameter, and the negative input terminal is also connected with the ground through a capacitor C23. The output terminal of the operational amplifier U4A is connected with the logic judgment circuit. The output terminal of the operational amplifier U4A is also connected with the 5V power supply through a resistor R43, and the 5V power supply is connected with the ground through a capacitor C1. The output terminal of the operational amplifier U4A is also connected with the ground through a capacitor C21, and the output terminal is also connected with the ground through a bidirectional breakdown diode D6.

[0025] The operational amplifier U4A is used as a comparator for comparing the output voltage value of the operational amplifier U5B with the over-temperature protection parameter. When the output signal of the operational amplifier U4A is high, it indicates that the circuit is normal and not in an over-current state; otherwise, it is in an over-current state.

[0026] As preferred: the under-voltage protection circuit is provided with an operational amplifier U8A, the positive input terminal of the operational amplifier U8A is connected to the 5V power source through a resistor R66 and connected to the ground through a resistor R67; the negative input terminal of the operational amplifier U8A is connected to the ground through a resistor R73 and connected to the output terminal of the operational amplifier U8A through a resistor R71, and the output terminal is connected to the negative input terminal of the operational amplifier U8B through a resistor R64;

[0027] The negative input terminal of the operational amplifier U8B is also connected to the output terminal through a resistor R63, the positive input terminal of the operational amplifier U8B is connected to the voltage detection terminal through a resistor R56 and connected to the ground through a resistor R57, and the output terminal of the operational amplifier U8B is connected to the positive input terminal of the operational amplifier U9B through a resistor R60;

[0028] The negative input terminal of the operational amplifier U9B obtains the under-voltage protection parameter, and the negative input terminal is also connected to the ground through a capacitor C34; the output terminal of the operational amplifier U9B is connected to the logic judgment circuit, and the output terminal of the operational amplifier U9B is connected to the 5V power source through a resistor R59, and the output terminal of the operational amplifier U9B is connected to the ground through a capacitor C32, and the output terminal is also connected to the ground through a bidirectional breakdown diode D8.

[0029] The operational amplifier U9B is used as a comparator for comparing the output voltage value of the operational amplifier U8B with the under-voltage protection parameter. When the output signal of the operational amplifier U9B is high, it indicates that the circuit is normal and not in an under-voltage state; otherwise, it is in an under-voltage state.

[0030] The over-voltage protection circuit is provided with a resistor R80, the front end of the resistor R80 is connected to the voltage detection terminal, and the rear end is connected to the ground through a resistor R81; the common end of the resistor R80 and the resistor R81 is connected to the positive input terminal of the operational amplifier U12A, the negative input terminal of the operational amplifier U12A is connected to the ground through a resistor R83, and the negative input terminal of the operational amplifier U12A is also connected to the output terminal of the operational amplifier U12A through a resistor R82, and the output terminal is connected to the negative input terminal of the operational amplifier U12B through a resistor R79;

[0031] The negative input terminal of the operational amplifier U12B is connected to the output terminal through a resistor R78, and the positive input terminal of the operational amplifier U12B is connected to a 5V power source through a resistor R75 and to the ground through a resistor R76, and the output terminal of the operational amplifier U12B is connected to the positive input terminal of the operational amplifier U9A through a resistor R74;

[0032] The negative input terminal of the operational amplifier U9A is connected to the overvoltage protection parameter, and the negative input terminal is connected to the ground through a capacitor C45, the output terminal of the operational amplifier U9A is connected to the logic judgment circuit, the output terminal of the operational amplifier U9A is connected to a 5V power source through a resistor R77, and the output terminal of the operational amplifier U9A is connected to the ground through a capacitor C43 and to the ground through a bidirectional breakdown diode D10.

[0033] The operational amplifier U9A is used as a comparator to compare the output voltage value of the operational amplifier U12B with the overvoltage protection parameter, and when the output signal of the operational amplifier U9A is high, it indicates that the circuit is normal and not in an overvoltage state; otherwise, it is in an overvoltage state.

[0034] As a preferred embodiment, the logic judgment circuit is provided with a logic judge U7 and a logic judge U10.

[0035] The overcurrent input terminal A2 of the logic judge U7 is connected to the overcurrent protection circuit, the overtemperature input terminal B2 is connected to the overtemperature protection circuit, and the undervoltage input terminal C2 is connected to the undervoltage protection circuit, and the output terminal of the logic judge U7 is connected to the first input terminal EN2 of the logic judge U10.

[0036] The overvoltage input terminal D2 of the logic judge U10 is connected to the overvoltage protection circuit, the IO input terminal IO2 of the logic judge U10 is connected to the IO control circuit, and the output terminal of the logic judge U10 is connected to the control start isolation circuit.

[0037] The logic judge U7 and the logic judge U10 are AND gate logic judges.

[0038] The logic judgment circuit is used for acquiring output signals of the overcurrent protection circuit, the overtemperature protection circuit, the undervoltage protection circuit, the overvoltage protection circuit and the IO control circuit. When the output signals of the overcurrent protection circuit, the overtemperature protection circuit, the undervoltage protection circuit, the overvoltage protection circuit and the IO control circuit are all high level signals, it indicates that the circuit is normal, the logic judgment circuit outputs a high level signal to the control start isolation circuit, and the control start isolation circuit controls the start circuit to continuously and stably output; when at least one of the output signals of the overcurrent protection circuit, the overtemperature protection circuit, the undervoltage protection circuit, the overvoltage protection circuit and the IO control circuit is a low level signal, the logic judgment circuit outputs a low level signal to the control start isolation circuit, the control start isolation circuit is turned off, and then the start circuit is turned off, so that the real-time protection of the overcurrent, overtemperature, undervoltage and overvoltage states of the circuit and the control of the working state of the load are realized.

[0039] As a preferred, the control start isolation circuit is provided with a photoelectric coupler D3, a positive input end of the photoelectric coupler D3 is connected with the logic judgment circuit, a negative input end of the photoelectric coupler D3 is connected with the ground through a resistor R15 in series, a positive output end of the photoelectric coupler D3 is connected with a 5V power supply through a resistor R14 in series, a negative output end of the photoelectric coupler D3 is connected with the ground through a resistor R16 and a capacitor C8 in series, a common end of the resistor R16 and the capacitor C8 is connected with a gate of a MOS tube Q1, the MOS tube Q1 is connected between the voltage dividing resistor R2 and a low level, wherein a source of the MOS tube Q1 is connected with the voltage dividing resistor R2, and a drain of the MOS tube Q1 is connected with the low level. The drain is further connected with the ground through a resistor R3 in series, the resistor R3 is a zero-ohm resistor, which is used for isolating the power ground and the analog ground.

[0040] The control start isolation circuit is used for controlling the conduction and the turn-off of the start circuit according to the output signal of the logic judgment circuit. When the logic judgment circuit signal acquired by the photoelectric coupler D3 is a high level signal, the photoelectric coupler D3 conducts and outputs a high level signal to the gate of the MOS tube Q1, the MOS tube Q1 conducts, and then the gate voltage of the MOS tube Q2 is pulled down, the MOS tube Q2 conducts, and the start circuit outputs a working voltage to the load.

[0041] The resistor R16 and the capacitor C8 have an RC delay function, which is used for controlling the delay conduction of the start circuit.

[0042] As a preferred, an ADC sampling circuit is further provided, the ADC sampling circuit is provided with a resistor R6, a front end of the resistor R6 is connected with the start circuit, a rear end of the resistor R6 is connected with an ADC sampling end of an MCU controller through a resistor R7 in series, the rear end of the resistor R6 is further connected with the ground through a resistor R12 in series, the rear end of the resistor R6 is further connected with the ground through a capacitor C3 in series, the rear end of the resistor R6 is further connected with a cathode of a voltage stabilizing diode D2, and an anode of the voltage stabilizing diode D2 is connected with the ground.

[0043] The ADC sampling circuit is used for sampling the output voltage of the starting circuit, so that the MCU controller can monitor the output voltage of the starting circuit in real time; the ADC sampling circuit collects the voltage division values of the voltage division resistors R6 and R12 in real time, and then monitors the output voltage of the starting circuit in real time through the voltage division values.

[0044] As preferred, the IO control circuit is provided with a resistor R37, a front end of the resistor R37 is connected to an IO signal output end of the MCU controller, a back end of the resistor R37 is connected to a base of a NPN type triode Q4, the back end is also connected to ground through a capacitor C18, the back end is also connected to ground through a resistor R38, a collector of the triode Q4 is connected to a 5V power supply through a resistor R36, an emitter of the triode Q4 is connected to the logic judgment circuit, the emitter of the triode Q4 is also connected to ground through a resistor R42, and the emitter of the triode Q4 is also connected to ground through a capacitor C20.

[0045] The MCU controller is used for controlling the working state of the load through the IO control circuit, when the IO control circuit outputs a high level, the working voltage is provided for the load, and the load normally works; when the IO control circuit outputs a low level, the power supply for the load is stopped, and the load does not work.

[0046] As preferred, a parameter setting circuit is further provided, the parameter setting circuit is provided with an overcurrent protection parameter setting circuit, an overtemperature protection parameter setting circuit, an undervoltage protection parameter setting circuit and an overvoltage protection parameter setting circuit.

[0047] The overcurrent protection parameter setting circuit, the overtemperature protection parameter setting circuit, the undervoltage protection parameter setting circuit and the overvoltage protection parameter setting circuit have the same structure, and are all provided with a resistor R13, a front end of the resistor R13 obtains a digital signal, and a back end of the resistor R13 is connected to a positive input end of an operational amplifier U1A, the back end of the resistor R13 is also connected to ground through a capacitor C6; an output end of the operational amplifier U1A is connected to an anode of a diode D1, the output end of the operational amplifier U1A is also connected to a negative input end through a resistor R5, and the negative input end is also connected to ground through a resistor R4;

[0048] A cathode of the diode D1 is connected to a front end of a resistor R9, a back end of the resistor R9 is connected to a front end of a resistor R10, the back end of the resistor R9 is also connected to ground through a capacitor C4, a back end of the resistor R10 is connected to a positive input end of an operational amplifier U1B, and the back end of the resistor R10 is also connected to ground through a capacitor C5.

[0049] The output end of the operational amplifier U1B is connected to the front end of the resistor R8, and the output end of the operational amplifier U1B is also connected to the ground through the capacitor C9 after being connected in series, the rear end of the resistor R8 is connected to the over-current protection circuit, the over-temperature protection circuit, the under-voltage protection circuit, the over-voltage protection circuit or the negative input end of the operational amplifier U1B, and the rear end of the resistor R8 is also connected to the ground through the capacitor C10 after being connected in series.

[0050] The parameter setting circuit is used for adjusting the over-current protection parameter, the over-temperature protection parameter, the under-voltage protection parameter and the over-voltage protection parameter according to actual conditions, so that the one kind of automobile electronic fuse can be adaptively adjusted according to the working voltage condition of different loads, and is adapted to the control protection of various loads, and has stronger practicability.

[0051] The utility model discloses beneficial effect:

[0052] 1. have overvoltage, under voltage, overcurrent, overtemperature and short circuit protection function simultaneously, and can automatically restore after overvoltage, under voltage, overcurrent, overtemperature and short circuit event end, and the use cost is lower;

[0053] 2. have the software parameter setting function, can modulate the protection parameter limit according to actual load, realize the adaptive adjustment of protection parameter, have the advantage of programmable, upgradeable and diagnosable, can satisfy different needs, and good compatibility with the intelligent system of vehicle is carried out;

[0054] 3. can real-time detection load working state;

[0055] 4. support portable replacement, and there is no electric shock risk when replacing traditional fuse.

[0056] 5. have longer service life, faster response speed, can effectively control transient voltage drop and large current problem;

[0057] 6. relatively small volume, help the optimization of whole car layout. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 It is the whole structure schematic diagram of the utility model;

[0059] Figure 2 It is the starting circuit and control starting isolation circuit diagram;

[0060] Figure 3 It is overcurrent protection circuit diagram;

[0061] Figure 4 It is overtemperature protection circuit diagram;

[0062] Figure 5 It is under-voltage protection circuit diagram;

[0063] Figure 6 for overvoltage protection circuit diagram;

[0064] Figure 7 for logic judgment circuit diagram;

[0065] Figure 8 for ADC sampling circuit diagram;

[0066] Figure 9 for IO control circuit diagram;

[0067] Figure 10 for parameter setting circuit diagram. DETAILED DESCRIPTION

[0068] The utility model will be further explained in detail below in combination with the drawings and specific examples. The following examples or drawings are used to explain the utility model, but not to limit the scope of the utility model.

[0069] As Figure 1 shown: a kind of mounted automobile electronic fuse, its key is: it is provided with starting circuit, overcurrent protection circuit, overtemperature protection circuit, undervoltage protection circuit, overvoltage protection circuit, logic judgment circuit and control starting isolation circuit;

[0070] The input end of the starting circuit obtains input power supply, and the output end outputs working voltage to load;

[0071] The starting circuit is provided with current detection end connected overcurrent protection circuit, and the output end of the overcurrent protection circuit is connected with the overcurrent input end of the logic judgment circuit;

[0072] The starting circuit is provided with voltage detection end connected overvoltage protection circuit and undervoltage protection circuit, the output end of the overvoltage protection circuit is connected with the overvoltage input end of the logic judgment circuit, and the output end of the undervoltage protection circuit is connected with the undervoltage input end of the logic judgment circuit;

[0073] The heating element of the starting circuit is connected with the temperature sensor of overtemperature protection circuit, and the output end of the overtemperature protection circuit is connected with the overtemperature input end of the logic judgment circuit;

[0074] The output end of the logic judgment circuit is connected with the input end of control starting isolation circuit, and the output end of the control starting isolation circuit controls the starting circuit.

[0075] It is also provided with ADC sampling circuit, IO control circuit and parameter setting circuit;

[0076] The sampling end of the ADC sampling circuit is connected with the voltage detection end, and the output end of the ADC sampling circuit is connected with MCU controller;The IO control input end of the IO control circuit is connected with MCU controller, and the output end is connected with the logic judgment circuit.

[0077] The parameter setting circuit includes an overcurrent protection parameter setting circuit, an overtemperature protection parameter setting circuit, an undervoltage protection parameter setting circuit, and an overvoltage protection parameter setting circuit, which provide corresponding protection parameters for each protection circuit.

[0078] like Figure 2 As shown: The startup circuit is equipped with a MOSFET Q2. The source of the MOSFET Q2 is connected to the input power supply, and the gate is connected to the input power supply after being connected in series with a voltage divider resistor R1. The gate is also connected to a low level after being connected in series with a voltage divider resistor R2. The drain of the MOSFET Q2 is connected to the load after being connected in series with a resistor R11.

[0079] The resistor R11 has a first current detection terminal at its front end and a second current detection terminal and a voltage detection terminal at its rear end; the MOSFET Q2 is connected to a temperature sensor.

[0080] like Figure 3 As shown: The overcurrent protection circuit includes a resistor R32. The front end of the resistor R32 is connected to the second current detection terminal, and the rear end is connected to ground via a series resistor R33. The common terminal of the resistors R32 and R33 is connected to the positive input terminal of the operational amplifier U2A. The negative input terminal of the operational amplifier U2A is connected to ground via a series resistor R35. The negative input terminal of the operational amplifier U2A is also connected to the output terminal via a series resistor R34. The output terminal is then connected to the negative input terminal of the operational amplifier U2B via a series resistor R31.

[0081] The negative input terminal of the operational amplifier U2B is connected in series with a resistor R29 and then to the output terminal. The positive input terminal of the operational amplifier U2B is connected in series with a resistor R17 and then to the first current detection terminal. The positive input terminal is also connected in series with resistors R18 and R19 and then to ground. The output terminal of the operational amplifier U2B is connected in series with a resistor R23 and then to the positive input terminal of the operational amplifier U4B.

[0082] The negative input terminal of the operational amplifier U4B obtains overcurrent protection parameters. This negative input terminal is also connected to ground via capacitor C15. The output terminal of the operational amplifier U4B is connected to a 5V power supply via resistor R22. This output terminal is also connected to ground via capacitor C14. This output terminal is also connected to ground via bidirectional breakdown diode D5. The output terminal of the operational amplifier U4B is also connected to the gate of MOSFET Q3 via resistor R26. The drain of MOSFET Q3 is grounded, and the source is connected to the logic judgment circuit. The source of MOSFET Q3 is also connected to a 5V power supply via resistor R20.

[0083] like Figure 4As shown: the over-temperature protection circuit is provided with a thermistor R52, the thermistor R52 connects the starting circuit heating element, the front end of the thermistor R52 is connected to 5V power supply, and the rear end is connected to ground through a resistor R48; the common end of the thermistor R52 and the resistor R48 is connected to the positive input end of the operational amplifier U5A, the negative input end of the operational amplifier U5A is connected to ground through a resistor R55, and the negative input end of the operational amplifier U5A is also connected to the output end of the operational amplifier U5A through a resistor R53, and the output end is connected to the negative input end of the operational amplifier U5B through a resistor R46;

[0084] The negative input end of the operational amplifier U5B is also connected to the output end through a resistor R45, the positive input end of the operational amplifier U5B is connected to the front end of the thermistor R52 through a resistor R40, and the positive input end is also connected to ground through a resistor R41, and the output end of the operational amplifier U5B is connected to the positive input end of the operational amplifier U4A through a resistor R39;

[0085] The negative input end of the operational amplifier U4A obtains the over-temperature protection parameter, and the negative input end is also connected to ground through a capacitor C23, the output end of the operational amplifier U4A is connected to the logic judgment circuit, the output end of the operational amplifier U4A is also connected to 5V power supply through a resistor R43, and the 5V power supply is connected to ground through a capacitor C1; the output end of the operational amplifier U4A is also connected to ground through a capacitor C21, and the output end is also connected to ground through a bidirectional breakdown diode D6.

[0086] As shown in Figure 5 The under-voltage protection circuit is provided with an operational amplifier U8A, the positive input end of the operational amplifier U8A is connected to 5V power supply through a resistor R66, and the positive input end is also connected to ground through a resistor R67; the negative input end of the operational amplifier U8A is connected to ground through a resistor R73, and the negative input end is also connected to the output end of the operational amplifier U8A through a resistor R71, and the output end is connected to the negative input end of the operational amplifier U8B through a resistor R64;

[0087] The negative input end of the operational amplifier U8B is also connected to the output end through a resistor R63, the positive input end of the operational amplifier U8B is connected to the voltage detection end through a resistor R56, and the positive input end is also connected to ground through a resistor R57; the output end of the operational amplifier U8B is connected to the positive input end of the operational amplifier U9B through a resistor R60;

[0088] The negative input end of the operational amplifier U9B obtains the under-voltage protection parameter, and the negative input end is also connected to the ground through a capacitor C34 in series; the output end of the operational amplifier U9B is connected to the logic judgment circuit; the output end of the operational amplifier U9B is also connected to a 5V power supply through a resistor R59 in series; the output end of the operational amplifier U9B is also connected to the ground through a capacitor C32 in series, and the output end is also connected to the ground through a bidirectional breakdown diode D8 in series.

[0089] As shown in Figure 6 The over-voltage protection circuit is provided with a resistor R80, the front end of the resistor R80 is connected to the voltage detection end, and the rear end is connected to the ground through a resistor R81 in series; the common end of the resistor R80 and the resistor R81 is connected to the positive input end of an operational amplifier U12A, the negative input end of the operational amplifier U12A is connected to the ground through a resistor R83 in series, and the negative input end of the operational amplifier U12A is also connected to the output end of the operational amplifier U12A through a resistor R82 in series, and the output end is connected to the negative input end of an operational amplifier U12B through a resistor R79 in series;

[0090] The negative input end of the operational amplifier U12B is also connected to the output end through a resistor R78 in series, the positive input end of the operational amplifier U12B is connected to a 5V power supply through a resistor R75 in series, the positive input end is also connected to the ground through a resistor R76 in series, and the output end of the operational amplifier U12B is connected to the positive input end of an operational amplifier U9A through a resistor R74 in series;

[0091] The negative input end of the operational amplifier U9A obtains the over-voltage protection parameter, and the negative input end is also connected to the ground through a capacitor C45 in series; the output end of the operational amplifier U9A is connected to the logic judgment circuit; the output end of the operational amplifier U9A is also connected to a 5V power supply through a resistor R77 in series; the output end of the operational amplifier U9A is also connected to the ground through a capacitor C43 in series, and the output end is also connected to the ground through a bidirectional breakdown diode D10 in series.

[0092] As shown in Figure 7 The logic judgment circuit is provided with a logic judge U7 and a logic judge U10;

[0093] The over-current input end A2 of the logic judge U7 is connected to the over-current protection circuit, the over-temperature input end B2 is connected to the over-temperature protection circuit, and the under-voltage input end C2 is connected to the under-voltage protection circuit; the output end of the logic judge U7 is connected to the first input end EN2 of the logic judge U10;

[0094] The over-voltage input end D2 of the logic judge U10 is connected to the over-voltage protection circuit, the IO input end IO2 of the logic judge U10 is connected to the IO control circuit, and the output end of the logic judge U10 is connected to the control start isolation circuit.

[0095] As shown in Figure 2As shown in the figure: the control start isolation circuit is provided with a photoelectric coupler D3, the positive input end of the photoelectric coupler D3 is connected to the logic judgment circuit, the negative input end is connected to the ground through a resistor R15, the positive output end of the photoelectric coupler D3 is connected to a 5V power supply through a resistor R14, the negative output end is connected to the ground through a resistor R16 and a capacitor C8 in sequence, the common end of the resistor R16 and the capacitor C8 is connected to the gate of a MOS tube Q1, the MOS tube Q1 is connected between the voltage dividing resistor R2 and the low level, wherein the source of the MOS tube Q1 is connected to the voltage dividing resistor R2, and the drain is connected to the low level.

[0096] As shown in the figure: Figure 8 The ADC sampling circuit is provided with a resistor R6, the front end of the resistor R6 is connected to the start circuit, the rear end of the resistor R6 is connected to the ADC sampling end of the MCU controller through a resistor R7, the rear end of the resistor R6 is also connected to the ground through a resistor R12, the rear end of the resistor R6 is also connected to the cathode of a voltage stabilizing diode D2, and the anode of the voltage stabilizing diode D2 is connected to the ground.

[0097] As shown in the figure: Figure 9 The IO control circuit is provided with a resistor R37, the front end of the resistor R37 is connected to the IO signal output end of the MCU controller, the rear end of the resistor R37 is connected to the base of a NPN type triode Q4, the rear end is also connected to the ground through a capacitor C18, and the rear end is also connected to the ground through a resistor R38, the collector of the triode Q4 is connected to a 5V power supply through a resistor R36, and the emitter is connected to the logic judgment circuit, the emitter of the triode Q4 is also connected to the ground through a resistor R42, and the emitter is also connected to the ground through a capacitor C20.

[0098] As shown in the figure: Figure 10 The overcurrent protection parameter setting circuit, the overtemperature protection parameter setting circuit, the undervoltage protection parameter setting circuit and the overvoltage protection parameter setting circuit have the same structure, and are all provided with a resistor R13, the front end of the resistor R13 obtains a digital signal, and the rear end is connected to the positive input end of an operational amplifier U1A, the rear end of the resistor R13 is also connected to the ground through a capacitor C6; the output end of the operational amplifier U1A is connected to the anode of a diode D1, and the output end of the operational amplifier U1A is also connected to the negative input end through a resistor R5, and the negative input end is also connected to the ground through a resistor R4.

[0099] The cathode of the diode D1 is connected to the front end of a resistor R9, the rear end of the resistor R9 is connected to the front end of a resistor R10, the rear end of the resistor R9 is also connected to the ground through a capacitor C4, and the rear end of the resistor R10 is connected to the positive input end of an operational amplifier U1B, and the rear end of the resistor R10 is also connected to the ground through a capacitor C5.

[0100] The output end of the operational amplifier U1B is connected to the front end of the resistor R8, and the output end of the operational amplifier U1B is also connected to the ground through a capacitor C9, and the rear end of the resistor R8 is connected to the overcurrent protection circuit, the temperature protection circuit, the undervoltage protection circuit, the overvoltage protection circuit, or the negative input end of the operational amplifier U1B, and the rear end of the resistor R8 is also connected to the ground through a capacitor C10.

[0101] R13 and C6 form an RC low-pass filter, which converts the high-frequency PWM signal into an approximate DC voltage. This conversion is achieved by smoothing the PWM signal. The higher the duty cycle of the PWM signal, the higher the average voltage after filtering, and vice versa.

[0102] The operational amplifier U1A is configured as a non-inverting amplifier, which amplifies the signal smoothed by the RC filter. Its output voltage is in phase with the input voltage, and it can provide sufficient driving capability to the subsequent circuit.

[0103] The diode D1 acts as a rectifier circuit, which converts the signal into a single polarity or clips the high voltage to ensure that the output voltage is within the desired range. This can protect the subsequent circuit from damage caused by excessive voltage.

[0104] R9 and C4 form the first-stage RC low-pass filter, which further smooths the signal after D1 and removes high-frequency components, making the signal closer to a DC voltage.

[0105] R10 and C5 form the second-stage RC low-pass filter, which further stabilizes and filters the signal to ensure a smooth and ripple-free output voltage.

[0106] The operational amplifier U1B is configured as a voltage follower, which provides a high input impedance and a low output impedance buffer effect. Its output voltage is consistent with the input voltage, and the main purpose is to not change the signal level while stably driving the load.

[0107] The duty cycle of the PWM signal directly affects the voltage value after the RC low-pass filter. The higher the duty cycle, the higher the average voltage after filtering. After the first-stage operational amplifier amplification and buffer processing, the voltage signal passes through the rectifier diode and then passes through two-stage RC low-pass filters for further smoothing, and finally reaches the second-stage operational amplifier, which also acts as a voltage follower, outputting a stable DC voltage. By adjusting the duty cycle of the PWM signal, this circuit can output different DC voltages. The entire process includes low-pass filtering of the PWM signal, amplification and buffering, rectification, further filtering, and finally outputting a stable voltage through the voltage follower. This design ensures that the output voltage accurately reflects the change in the duty cycle of the PWM signal, while providing good signal stability and driving capability.

[0108] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A piggyback automotive electronic fuse, characterized by: The starting circuit is provided with a starting circuit, an overcurrent protection circuit, an overtemperature protection circuit, an undervoltage protection circuit, an overvoltage protection circuit, a logic judgment circuit and a control starting isolation circuit; The input end of the starting circuit obtains an input power supply, and the output end outputs a working voltage to a load; The starting circuit is provided with a current detection end connected to the overcurrent protection circuit, and the output end of the overcurrent protection circuit is connected to the overcurrent input end of the logic judgment circuit; The starting circuit is provided with a voltage detection end connected to the overvoltage protection circuit and the undervoltage protection circuit, the output end of the overvoltage protection circuit is connected to the overvoltage input end of the logic judgment circuit, and the output end of the undervoltage protection circuit is connected to the undervoltage input end of the logic judgment circuit; The starting circuit is provided with a temperature sensor connected to the overtemperature protection circuit, and the output end of the overtemperature protection circuit is connected to the overtemperature input end of the logic judgment circuit; The output end of the logic judgment circuit is connected to the input end of the control starting isolation circuit, and the output end of the control starting isolation circuit controls the starting circuit.

2. The piggyback automotive electronic fuse of claim 1, wherein: The starting circuit is provided with a MOS tube Q2, the source electrode of the MOS tube Q2 is connected to an input power supply, the gate electrode is connected to the input power supply through a voltage dividing resistor R1, and the gate electrode is also connected to a low voltage through a voltage dividing resistor R2, and the drain electrode of the MOS tube Q2 is connected to a load through a resistor R11. The front end of the resistor R11 is provided with a first current detection end, and the rear end is provided with a second current detection end and a voltage detection end; the MOS tube Q2 is connected with a temperature sensor.

3. The piggyback automotive electronic fuse of claim 2, wherein: The overcurrent protection circuit is provided with a resistor R32, the front end of the resistor R32 is connected to the second current detection end, and the rear end is connected to the ground through a resistor R33; the common end of the resistor R32 and the resistor R33 is connected to the positive input end of an operational amplifier U2A, the negative input end of the operational amplifier U2A is connected to the ground through a resistor R35, and the negative input end of the operational amplifier U2A is also connected to the output end of the operational amplifier U2A through a resistor R34, and the output end is connected to the negative input end of an operational amplifier U2B through a resistor R31; The negative input end of the operational amplifier U2B is also connected to the output end through a resistor R29, the positive input end of the operational amplifier U2B is connected to the first current detection end through a resistor R17, and the positive input end is also connected to the ground through a resistor R18 and a resistor R19 in sequence, and the output end of the operational amplifier U2B is connected to the positive input end of an operational amplifier U4B through a resistor R23; The negative input end of the operational amplifier U4B obtains an overcurrent protection parameter, and the negative input end is also connected to the ground through a capacitor C15, the output end of the operational amplifier U4B is connected to a 5V power supply through a resistor R22, the output end is also connected to the ground through a capacitor C14, the output end is also connected to the ground through a bidirectional breakdown diode D5, the output end of the operational amplifier U4B is also connected to the gate electrode of a MOS tube Q3 through a resistor R26, the drain electrode of the MOS tube Q3 is connected to the ground, the source electrode is connected to the logic judgment circuit, and the source electrode of the MOS tube Q3 is also connected to a 5V power supply through a resistor R20.

4. The piggyback automotive electronic fuse of claim 1, wherein: The over-temperature protection circuit is provided with a thermistor R52 connected to the starting circuit heat generating element, the front end of the thermistor R52 is connected to a 5V power supply, and the rear end is connected to the ground after connecting a resistor R48; the common end of the thermistor R52 and the resistor R48 is connected to the positive input end of an operational amplifier U5A, the negative input end of the operational amplifier U5A is connected to the ground after connecting a resistor R55, and the negative input end of the operational amplifier U5A is also connected to the output end of the operational amplifier U5A after connecting a resistor R53, and the output end is connected to the negative input end of an operational amplifier U5B after connecting a resistor R46; The negative input end of the operational amplifier U5B is also connected to the output end after connecting a resistor R45, the positive input end of the operational amplifier U5B is connected to the front end of the thermistor R52 after connecting a resistor R40, and the positive input end is also connected to the ground after connecting a resistor R41, and the output end of the operational amplifier U5B is connected to the positive input end of an operational amplifier U4A after connecting a resistor R39; The negative input end of the operational amplifier U4A obtains an over-temperature protection parameter, and the negative input end is also connected to the ground after connecting a capacitor C23, and the output end of the operational amplifier U4A is connected to the logic judgment circuit, and the output end of the operational amplifier U4A is also connected to a 5V power supply after connecting a resistor R43, and the 5V power supply is connected to the ground after connecting a capacitor C1; the output end of the operational amplifier U4A is also connected to the ground after connecting a capacitor C21, and the output end is also connected to the ground after connecting a bidirectional breakdown diode D6.

5. The piggyback automotive electronic fuse of claim 1, wherein: The under-voltage protection circuit is provided with an operational amplifier U8A, the positive input end of the operational amplifier U8A is connected to a 5V power supply after connecting a resistor R66, and the positive input end is also connected to the ground after connecting a resistor R67; the negative input end of the operational amplifier U8A is connected to the ground after connecting a resistor R73, and the negative input end is also connected to the output end of the operational amplifier U8A after connecting a resistor R71, and the output end is connected to the negative input end of an operational amplifier U8B after connecting a resistor R64; The negative input end of the operational amplifier U8B is also connected to the output end after connecting a resistor R63, and the positive input end of the operational amplifier U8B is connected to the voltage detection end after connecting a resistor R56, and the positive input end is also connected to the ground after connecting a resistor R57, and the output end of the operational amplifier U8B is connected to the positive input end of an operational amplifier U9B after connecting a resistor R60; The negative input end of the operational amplifier U9B obtains an under-voltage protection parameter, and the negative input end is also connected to the ground after connecting a capacitor C34, and the output end of the operational amplifier U9B is connected to the logic judgment circuit, and the output end of the operational amplifier U9B is also connected to a 5V power supply after connecting a resistor R59, and the output end of the operational amplifier U9B is also connected to the ground after connecting a capacitor C32, and the output end is also connected to the ground after connecting a bidirectional breakdown diode D8; The overvoltage protection circuit is provided with a resistor R80, the front end of the resistor R80 is connected to the voltage detection end, and the rear end is connected to the ground through a resistor R81; the common end of the resistor R80 and the resistor R81 is connected to the positive input end of an operational amplifier U12A, the negative input end of the operational amplifier U12A is connected to the ground through a resistor R83, and the negative input end of the operational amplifier U12A is also connected to the output end of the operational amplifier U12A through a resistor R82, and the output end is connected to the negative input end of an operational amplifier U12B through a resistor R79. The negative input end of the operational amplifier U12B is also connected to the output end through a resistor R78, the positive input end of the operational amplifier U12B is connected to a 5V power supply through a resistor R75, and the positive input end is also connected to the ground through a resistor R76; the output end of the operational amplifier U12B is connected to the positive input end of an operational amplifier U9A through a resistor R74. The negative input end of the operational amplifier U9A obtains an overvoltage protection parameter, the negative input end is also connected to the ground through a capacitor C45, the output end of the operational amplifier U9A is connected to the logic judgment circuit, the output end of the operational amplifier U9A is also connected to a 5V power supply through a resistor R77, the output end of the operational amplifier U9A is also connected to the ground through a capacitor C43, and the output end is also connected to the ground through a bidirectional breakdown diode D10.

6. The piggyback automotive electronic fuse of claim 1, wherein: The logic judgment circuit is provided with a logic judge U7 and a logic judge U10. The overcurrent input end A2 of the logic judge U7 is connected to the overcurrent protection circuit, the overtemperature input end B2 is connected to the overtemperature protection circuit, and the undervoltage input end C2 is connected to the undervoltage protection circuit; the output end of the logic judge U7 is connected to the first input end EN2 of the logic judge U10. The overvoltage input end D_2 of the logic judge U10 is connected to the overvoltage protection circuit, the IO input end IO2 of the logic judge U10 is connected to the IO control circuit, and the output end of the logic judge U10 is connected to the control start isolation circuit.

7. The on-board automotive electronic fuse of claim 2, wherein: The control start isolation circuit is provided with an optoelectronic coupler D3, the positive input end of the optoelectronic coupler D3 is connected to the logic judgment circuit, the negative input end is connected to the ground through a resistor R15, the positive output end of the optoelectronic coupler D3 is connected to a 5V power supply through a resistor R14, the negative output end is connected to the ground in sequence through a resistor R16 and a capacitor C8, the common end of the resistor R16 and the capacitor C8 is connected to the gate of a MOS tube Q1, and the MOS tube Q1 is connected between the voltage dividing resistor R2 and the low level, wherein the source of the MOS tube Q1 is connected to the voltage dividing resistor R2, and the drain is connected to the low level.

8. The piggyback automotive electronic fuse of claim 1, wherein: An ADC sampling circuit is also provided, the ADC sampling circuit is provided with a resistor R6, the front end of the resistor R6 is connected to the start circuit, the rear end is connected to the ADC sampling end of the MCU controller through a resistor R7, the rear end of the resistor R6 is also connected to the ground through a resistor R12, the rear end is also connected to the ground through a capacitor C3, the rear end of the resistor R6 is also connected to the cathode of a stabilizing diode D2, and the anode of the stabilizing diode D2 is connected to the ground.

9. The piggyback automotive electronic fuse of claim 8, wherein: The IO control circuit is provided with a resistor R37, a front end of the resistor R37 is connected with an IO signal output end of the MCU controller, a back end of the resistor R37 is connected with a base of a NPN type triode Q4, the back end is also connected with a ground through a capacitor C18, the back end is also connected with a ground through a resistor R38, a collector of the triode Q4 is connected with a 5V power supply through a resistor R36, an emitter of the triode Q4 is connected with the logic judgment circuit, the emitter of the triode Q4 is also connected with a ground through a resistor R42, and the emitter of the triode Q4 is also connected with a ground through a capacitor C20.

10. The piggyback automotive electronic fuse of claim 1, wherein: The parameter setting circuit is also provided, and the parameter setting circuit is provided with an overcurrent protection parameter setting circuit, an overtemperature protection parameter setting circuit, an undervoltage protection parameter setting circuit and an overvoltage protection parameter setting circuit; The overcurrent protection parameter setting circuit, the overtemperature protection parameter setting circuit, the undervoltage protection parameter setting circuit and the overvoltage protection parameter setting circuit are consistent in structure, and are all provided with a resistor R13, a front end of the resistor R13 obtains a digital signal, and a back end of the resistor R13 is connected with a positive input end of an operational amplifier U1A, and the back end of the resistor R13 is also connected with a ground through a capacitor C6; an output end of the operational amplifier U1A is connected with an anode of a diode D1, and the output end of the operational amplifier U1A is also connected with a negative input end of the operational amplifier U1A through a resistor R5 and a ground through a resistor R4; A cathode of the diode D1 is connected with a front end of a resistor R9, a back end of the resistor R9 is connected with a front end of a resistor R10, the back end of the resistor R9 is also connected with a ground through a capacitor C4, a back end of the resistor R10 is connected with a positive input end of an operational amplifier U1B, and the back end of the resistor R10 is also connected with a ground through a capacitor C5; An output end of the operational amplifier U1B is connected with a front end of a resistor R8, the output end of the operational amplifier U1B is also connected with a ground through a capacitor C9, the back end of the resistor R8 is connected with an overcurrent protection circuit, an overtemperature protection circuit, an undervoltage protection circuit or an overvoltage protection circuit, and the back end of the resistor R8 is also connected with a negative input end of the operational amplifier U1B, and the negative input end is also connected with a ground through a capacitor C10.

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